CA3150497A1 - Magnetic bearings and electric motors - Google Patents
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Abstract
Disclosed are various embodiments of a magnetic bearing, an electric stepper motor and an electric motor with positional sensing.
Description
MAGNETIC BEARINGS AND ELECTRIC MOTORS
CROSS REFERENCE TO RELATED APPLICATIONS
[001] This application claims priority to International Patent Application No.
PCT/US2021/042859, filed on July 22, 2021. This application further claims priority to U.S.
Continuation Patent Application No. 17/497,033 filed on October 8, 2021, U.S
Continuation Patent Application No. 17/501,424 filed October 14, 2021, and U.S.
Continuation Patent Application No. 17/534,390 filed November 23, 2021.
FIELD OF THE DISCLOSURE
CROSS REFERENCE TO RELATED APPLICATIONS
[001] This application claims priority to International Patent Application No.
PCT/US2021/042859, filed on July 22, 2021. This application further claims priority to U.S.
Continuation Patent Application No. 17/497,033 filed on October 8, 2021, U.S
Continuation Patent Application No. 17/501,424 filed October 14, 2021, and U.S.
Continuation Patent Application No. 17/534,390 filed November 23, 2021.
FIELD OF THE DISCLOSURE
[002] The present disclosure relates broadly to magnetic bearings and electric motors, which have inter alia a novel configuration of permanent magnets. In particular, this disclosure relates to a new type of magnetic bearing which uses piezoelectric elements to push permanent magnets or electromagnets together or pull them apart, allowing the magnetic bearing to withstand high amounts of torque with high efficiency. Novel configurations of permanent magnets allow the magnetic bearing to remain stable at load and over long operating times. In addition, this disclosure relates to a new type of electric stepper motor which uses piezoelectric elements to push permanent magnets or electromagnets together or pull them apart to create rotational force, delivering high amounts of torque with high efficiency and high precision.
Novel configurations of permanent magnets allow the motor assembly to deliver large amounts of torque while providing high precision while remaining stable at load and over long operating times. Yet further, this disclosure relates to a new type of electronic motor with a position sensor which uses piezoelectric elements to detect the interaction of permanent magnets or electromagnets. The sensor is integrated into a brushless electric motor design. Novel configurations of permanent magnets allow the motor assembly to deliver large amounts of torque while remaining stable at load and over long operating times but still delivering extremely precise and reliable sensor position information.
Date Recue/Date Received 2022-02-28 BACKGROUND
Novel configurations of permanent magnets allow the motor assembly to deliver large amounts of torque while providing high precision while remaining stable at load and over long operating times. Yet further, this disclosure relates to a new type of electronic motor with a position sensor which uses piezoelectric elements to detect the interaction of permanent magnets or electromagnets. The sensor is integrated into a brushless electric motor design. Novel configurations of permanent magnets allow the motor assembly to deliver large amounts of torque while remaining stable at load and over long operating times but still delivering extremely precise and reliable sensor position information.
Date Recue/Date Received 2022-02-28 BACKGROUND
[003] One aspect of the present disclosure relates to a magnetic bearing.
Magnetic bearings are well-known in the art: the fact that similar poles of a magnet repel each other has been used for everything up to and including levitating entire high-speed trains. The advantages of magnetic bearings are that they can be switched on and off, or varied in power as required by the load, and that they are entirely contact-free, which means that there is no physical friction between the bearing and the load as there would be when using a roller bearing, ball bearing, or other type conventional physical bearing.
Magnetic bearings are well-known in the art: the fact that similar poles of a magnet repel each other has been used for everything up to and including levitating entire high-speed trains. The advantages of magnetic bearings are that they can be switched on and off, or varied in power as required by the load, and that they are entirely contact-free, which means that there is no physical friction between the bearing and the load as there would be when using a roller bearing, ball bearing, or other type conventional physical bearing.
[004] While magnetic bearings were a large improvement over physical bearings in many ways, as they have less frictional load, they have many inefficiencies. Most magnetic bearings use electromagnets. Constantly power cycling and/or reversing the electromagnets causes electrical inefficiencies, and the windings of the electromagnets can suffer fatigue and/or heat breakdown which causes the bearing to become inefficient or stop functioning.
[005] Electromagnets are also fairly heavy and contribute to parasitic load and/or weight inefficiency.
[006] A magnetic bearing which did not use electromagnets and therefore was more efficient and more economical to build would be a useful invention. A magnetic bearing which did not use electromagnets and was therefore more efficient and economical to power would be a useful invention. A magnetic bearing which did not use electromagnets and was therefore more durable and reliable would be a useful invention. This aspect of the present disclosure, relating to a magnetic bearing, may at least partially address these concerns.
[007] Another aspect of the present disclosure relates to electric stepper motors. Electric stepper motors are well-known in the art: electric stepper motors date from the first half of the 20th Century.
[008] Stepper motors are electric motors which use gears or other physical positional detection means to switch the motor on and off when it moves through a fixed fraction of its full rotation. Traditionally, the gear uses a switching system of some kind and turns the motor off after it moves through a fixed fraction of its rotation. In such motors it is necessary to turn the motor on, let it advance one fixed fraction, and then turn it on again, repeating until it Date Recue/Date Received 2022-02-28 reaches the desired number of full or fractional rotations.
[009] For instance, if the fixed fraction is one-one-hundredth of a full rotation, and it is desired to rotate the motor through half a rotation, the motor must go through fifty "steps" of activation, movement, and deactivation. If it is desired to rotate the motor through two and a half rotations, the motor must go through two hundred and fifty steps. As is obvious, the more steps that are used, the more possibility for error or uncertainty enters into a given set of rotations. Also, gears wear, producing additional uncertainty and eventual failure in the precise rotation of the stepper motor.
[0010] Like most modern motors, most stepper motors use electromagnets to turn electrical energy into rotational energy. Electromagnets are expensive, heavy, and prone to multiple kinds of failure. They are also very energy- inefficient and uneconomical to operate.
[0011] An electric stepper motor which did not use gears or equivalent physical on/off controls and was therefore more durable and reliable would be a useful invention. An electric stepper motor which did not use electromagnets and therefore was more efficient and more economical to build would be a useful invention. An electric stepper motor which did not use electromagnets and was therefore more efficient and economical to power would be a useful invention. An electric stepper motor which did not use electromagnets andwas therefore more durable and reliable would be a useful invention. An electric stepper motor which did not use electromagnets and was therefore lighter than a motor of equivalent output which did use electromagnets would be a useful invention. This aspect of the present disclosure, relating to electric stepper motors, may at least partially address these concerns.
[0012] Another aspect of the present disclosure relates to a brushless electric motor with integrated positional sensing. Electric motors and positional sensing are well-known in the art:
the "brushless" type of electric motor dates from the latter half of the 20th Century and uses solid-state electronics to replace the physical commutator (polarity reversal switch) that allowed brush-type electric motors to function. Positional sensing, dating back to switches that tripped when an element of a larger machine physically engaged them, is likewise well-known in the art.
the "brushless" type of electric motor dates from the latter half of the 20th Century and uses solid-state electronics to replace the physical commutator (polarity reversal switch) that allowed brush-type electric motors to function. Positional sensing, dating back to switches that tripped when an element of a larger machine physically engaged them, is likewise well-known in the art.
[0013] While brushless motors were a large improvement in many ways, as they have less frictional load and fewer mechanical parts, they have many inefficiencies.
Constantly reversing Date Recue/Date Received 2022-02-28 the electromagnets causes electrical inefficiencies, and the windings of the electromagnets can suffer fatigue and/or heat breakdown which causes the motor to become inefficient or stop functioning. While brushless motors are typically more than 50% efficient in terms of mechanical energy out compared to electrical energy in, they do suffer from loss of energy due to various factors such as wire heating, resistance, et cetera. Brushless motors require intricately wound electromagnetic rotor and/or stator magnets which are expensive and inefficient to construct.
Constantly reversing Date Recue/Date Received 2022-02-28 the electromagnets causes electrical inefficiencies, and the windings of the electromagnets can suffer fatigue and/or heat breakdown which causes the motor to become inefficient or stop functioning. While brushless motors are typically more than 50% efficient in terms of mechanical energy out compared to electrical energy in, they do suffer from loss of energy due to various factors such as wire heating, resistance, et cetera. Brushless motors require intricately wound electromagnetic rotor and/or stator magnets which are expensive and inefficient to construct.
[0014] Electromagnets are also fairly heavy and contribute to parasitic load and/or weight inefficiency. Historically, positional sensing was done by some external detection means, such .. as a switch or counter. This adds complexity and expense. Traditional electric motors can also be used to detect countermotion by a load or torque: if something moves the rotor of an electric motor, it will induce a current in the motor. (As is well known to persons of ordinary skill in the art, if you turn a motor, you create a generator.) The current can be detected and used to indicate that the motor is being turned. However, traditional motors do not provide fine enough .. creation and detection of such currents to precisely identify the position of the motor's rotor or elements affixed to the rotor of the motor. In many applications, such as robotics, it would be extremely useful to be able to precisely detect the position/motion of the rotor of a motor or the elements affixed to the rotor of the motor.
[0015] An electric motor with positional sensing which did not use electromagnets and therefore was more efficient and more economical to build would be a useful invention. An electric motor with positional sensing which did not use electromagnets and was therefore more efficient and economical to power would be a useful invention. An electric motor with positional sensing which did not use electromagnets and was therefore more durable and reliable would be a useful invention. An electric motor with positional sensing which did not .. use electromagnets and was therefore lighter than a motor of equivalent output which did use electromagnets would be a useful invention. An electric motor with positional sensing which did not require external detection means and produced a precise measurement of the position and/or motion of the motor would be a useful invention. This aspect of the present disclosure, relating to a brushless electric motor with integrated positional sensing, may at least partially address these concerns.
Date Recue/Date Received 2022-02-28
Date Recue/Date Received 2022-02-28
[0016] This background information is provided to reveal information believed by the applicant to be of possible relevance. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art or forms part of the general common knowledge in the relevant art.
SUMMARY
SUMMARY
[0017] The following presents a simplified summary of the general inventive concept(s) described herein to provide a basic understanding of some aspects of the disclosure. This summary is not an extensive overview of the disclosure. It is not intended to restrict key or critical elements of embodiments of the disclosure or to delineate their scope beyond that which is explicitly or implicitly described by the following description and claims.
[0018] Generally, among the many objectives of the present disclosure is the provision of a magnetic bearing. One objective is the provision of a magnetic bearing which uses piezoelectric impulse and permanent magnets as a source of generating mechanical energy from electrical energy and using that mechanical energy to support and control the magnetic bearing. Another objective is the provision of a magnetic bearing which does not use electromagnets and is therefore more efficient and economical to construct. Another objective is the provision of a magnetic bearing which does not use electromagnets and is therefore more efficient and economical to operate. Yet another objective is the provision of a magnetic bearing which does not use electromagnets and is therefore more durable and easier to maintain.
Other advantages and objectives of the magnetic bearing disclosed will become clear by reading the application and the disclosures herein.
Other advantages and objectives of the magnetic bearing disclosed will become clear by reading the application and the disclosures herein.
[0019] In accordance with one aspect of the present disclosure, there is provided a magnetic bearing comprising: a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply; b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the Date Recue/Date Received 2022-02-28 variable gap changes; and d) a bearing assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that a magnetic repulsion force between the actuator magnets and the response magnets acts to maintain the size of the variable gap against a load.
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the Date Recue/Date Received 2022-02-28 variable gap changes; and d) a bearing assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that a magnetic repulsion force between the actuator magnets and the response magnets acts to maintain the size of the variable gap against a load.
[0020] In one embodiment, there is one and only one group of piezoelectric actuators, and the one and only one group of piezoelectric actuators comprises one and only one piezoelectric actuator, and there is one and only one group of actuator magnets, and the one and only one group of actuator magnets comprises two actuator magnets.
[0021] In one embodiment, the group of response magnets comprises a single piece of magnetic material, the single piece of magnetic material having a plurality of magnetic regions, each magnetic region having a local north pole and a local south pole.
[0022] In one embodiment, the magnetic bearing further comprises e) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0023] In one embodiment, there are two groups of piezoelectric actuators, further comprising:
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators forming a group of rotor piezoelectric actuators, each of the .. rotor piezoelectric actuators mechanically affixed to a rotor magnet.
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators forming a group of rotor piezoelectric actuators, each of the .. rotor piezoelectric actuators mechanically affixed to a rotor magnet.
[0024] In one embodiment, the magnetic bearing further comprises g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or Date Recue/Date Received 2022-02-28 more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0025] In one embodiment, each group of actuator magnets has two ends, and the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
[0026] In one embodiment, each group of actuator magnets has two ends, and the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
[0027] In one embodiment, the magnetic bearing further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0028] In one embodiment, the magnetic bearing further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0029] In one embodiment, the magnetic bearing further comprises f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such Date Recue/Date Received 2022-02-28 that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0030] In one embodiment, the magnetic bearing further comprises e) a group of elastic .. members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0031] In accordance with another aspect of the present disclosure, there is provided a magnetic bearing comprising: a) at least one group of static piezoelectric actuators, the at least one group of static piezoelectric actuators comprising at least one static piezoelectric actuator, all of the static piezoelectric actuators electrically connected to a power supply; b) a group of static magnets, the group of static magnets comprising at least one static magnet, each of the at least one static piezoelectric actuators mechanically affixed to the group of static magnets;
c) at least one group of mobile piezoelectric actuators, the at least one group of mobile piezoelectric actuators comprising at least one mobile piezoelectric actuator, all of the mobile piezoelectric actuators electrically connected to the power supply; d) a group of mobile magnets, the group of mobile magnets comprising at least one mobile magnet, each of the at least one mobile piezoelectric actuators mechanically affixed to the group of mobile magnets;
e) a motor assembly having a mobile assembly and a static assembly, the mobile assembly mechanically affixed to the group of mobile piezoelectric actuators, the static assembly mechanically affixed to the group of static piezoelectric actuators, such that there is a variable gap having a size between the group of mobile magnets and the group of static magnets and when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly.
c) at least one group of mobile piezoelectric actuators, the at least one group of mobile piezoelectric actuators comprising at least one mobile piezoelectric actuator, all of the mobile piezoelectric actuators electrically connected to the power supply; d) a group of mobile magnets, the group of mobile magnets comprising at least one mobile magnet, each of the at least one mobile piezoelectric actuators mechanically affixed to the group of mobile magnets;
e) a motor assembly having a mobile assembly and a static assembly, the mobile assembly mechanically affixed to the group of mobile piezoelectric actuators, the static assembly mechanically affixed to the group of static piezoelectric actuators, such that there is a variable gap having a size between the group of mobile magnets and the group of static magnets and when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly.
[0032] In one embodiment, the magnetic bearing further comprises f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of .. capacitor plates are energized by the power supply, they form a capacitor circuit with one or Date Recue/Date Received 2022-02-28 more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0033] In one embodiment, each group of static magnets and/or each group of mobile magnets is a group of magnets containing at least two magnets, and each group of magnets has two ends, and the magnets in each group of magnets overlap each other to produce a combined magnetic field, and each of the magnets in a group of magnets has a north pole and a south pole, and the south pole of any particular magnet is either physically proximate to one of the two ends, or to the north pole of another magnet in the same group of magnets, and the north pole of any particular magnet is either physically proximate to one of the two ends, or to the south pole of another magnet in the same group of magnets.
[0034] In one embodiment, the piezoelectric actuators are electrically connected to the power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by the power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
[0035] In one embodiment, the magnetic bearing further comprises e) a frequency controller, the frequency controller controlling the power supply such that the frequency controller can cause the power supply to apply a positive voltage or a negative voltage to one or more of the piezoelectric actuators.
[0036] In one embodiment, the magnetic bearing further comprises f) a heat sensor, the heat sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a detected temperature.
[0037] In one embodiment, the magnetic bearing further comprises f) a gap sensor, the gap sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a change in the size of the variable gap.
Date Recue/Date Received 2022-02-28
Date Recue/Date Received 2022-02-28
[0038] In one embodiment, the magnetic bearing further comprises f) an acceleration sensor, the acceleration sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a detected acceleration.
[0039] In one embodiment, the magnetic bearing further comprises f) a gap sensor, the gap sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a change in the size of the variable gap.
[0040] Generally, among the many objectives of the present disclosure is the provision of an electric stepper motor. One objective is the provision of an electric stepper motor which uses piezoelectric impulse and permanent magnets as a source of generating mechanical energy from electrical energy and rotating the motor through a very precise rotation.
Another objective is the provision of an electric stepper motor which does not use electromagnets and is therefore more efficient and economical to construct. Another objective is the provision of an electric stepper motor which does not use electromagnets and is therefore more efficient and economical to operate. Yet another objective is the provision of an electric stepper motor which does not use electromagnets and is therefore more durable and easier to maintain. Still another objective of an electric stepper motor which does not use electromagnets and is therefore lighter in weight than a traditional electric stepper motor of equivalent output.
Other advantages and objectives of the electric stepper motor will become clear by reading the application and the disclosures herein.
Another objective is the provision of an electric stepper motor which does not use electromagnets and is therefore more efficient and economical to construct. Another objective is the provision of an electric stepper motor which does not use electromagnets and is therefore more efficient and economical to operate. Yet another objective is the provision of an electric stepper motor which does not use electromagnets and is therefore more durable and easier to maintain. Still another objective of an electric stepper motor which does not use electromagnets and is therefore lighter in weight than a traditional electric stepper motor of equivalent output.
Other advantages and objectives of the electric stepper motor will become clear by reading the application and the disclosures herein.
[0041] In accordance with another aspect of the present disclosure, there is provided an electric stepper motor comprising: a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a switching power supply; b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the switching power supply, the size of the variable gap changes; d) a motor assembly including a mobile assembly and a static Date Recue/Date Received 2022-02-28 assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and e) a frequency controller, electrically connected to the switching power supply, which causes the switching power supply to energize, and then de-energize, some or all of the piezoelectric actuators a fixed number of times such that the mobile assembly moves a target fixed distance.
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the switching power supply, the size of the variable gap changes; d) a motor assembly including a mobile assembly and a static Date Recue/Date Received 2022-02-28 assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and e) a frequency controller, electrically connected to the switching power supply, which causes the switching power supply to energize, and then de-energize, some or all of the piezoelectric actuators a fixed number of times such that the mobile assembly moves a target fixed distance.
[0042] In one embodiment, there is one and only one group of piezoelectric actuators, and the one and only one group of piezoelectric actuators comprises one and only one piezoelectric actuator, and there is one and only one group of actuator magnets, and the one and only one group of actuator magnets comprises two actuator magnets.
[0043] In one embodiment, the group of response magnets comprises a single piece of magnetic material, the single piece of magnetic material having a plurality of magnetic regions, each magnetic region having a local north pole and a local south pole.
[0044] In one embodiment, the electric stepper motor further comprises f) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0045] In one embodiment, there are two groups of piezoelectric actuators, further comprising:
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators forming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators forming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
[0046] In one embodiment, the electric stepper motor further comprises g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator 3021P-MBE-CAD1 1]
Date Recue/Date Received 2022-02-28 capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
Date Recue/Date Received 2022-02-28 capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0047] In one embodiment, each group of actuator magnets has two ends, and the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
[0048] In one embodiment, the actuator magnets in each group of actuator magnets are secured by an adhesive, the adhesive securing the actuator magnets in a fixed orientation.
[0049] In one embodiment, the electric stepper motor further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0050] In one embodiment, the electric stepper motor further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0051] In one embodiment, the electric stepper motor further comprises f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
Date Recue/Date Received 2022-02-28
Date Recue/Date Received 2022-02-28
[0052] In accordance with another aspect of the present disclosure, there is provided an electric stepper motor comprising: a) at least one group of static piezoelectric actuators, the at least one group of static piezoelectric actuators comprising at least one static piezoelectric actuator, all of the static piezoelectric actuators electrically connected to a switching power supply; b) a group of static magnets, the group of static magnets comprising at least one static magnet, each of the at least one static piezoelectric actuators mechanically affixed to the group of static magnets; c) at least one group of mobile piezoelectric actuators, the at least one group of mobile piezoelectric actuators comprising at least one mobile piezoelectric actuator, all of the mobile piezoelectric actuators electrically connected to the switching power supply; d) a group of mobile magnets, the group of mobile magnets comprising at least one mobile magnet, each of the at least one mobile piezoelectric actuators mechanically affixed to the group of mobile magnets; e) a motor assembly having a mobile assembly and a static assembly, the mobile assembly mechanically affixed to the group of mobile piezoelectric actuators, the static assembly mechanically affixed to the group of static piezoelectric actuators, such that there is a variable gap having a size between the group of mobile magnets and the group of static magnets and when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and f) a frequency controller, electrically connected to the switching power supply, which causes the switching power supply to energize, and then de-energize, some or all of the static piezoelectric actuators and/or some or all of the mobile piezoelectric actuators a fixed number of times such that the mobile assembly moves a target fixed distance.
[0053] In one embodiment, the electric stepper motor further comprises g) a group of elastic members, the elastic members mechanically affixed to at least one of the static or mobile piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0054] In one embodiment, the electric stepper motor further comprises f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they form a capacitor circuit Date Recue/Date Received 2022-02-28 with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0055] In one embodiment, each group of static magnets and/or each group of mobile magnets is a group of magnets containing at least two magnets, and each group of magnets has two .. ends, and the magnets in each group of magnets overlap each other to produce a combined magnetic field, and each of the magnets in a group of magnets has a north pole and a south pole, and the south pole of any particular magnet is either physically proximate to one of the two ends, or to the north pole of another magnet in the same group of magnets, and the north pole of any particular magnet is either physically proximate to one of the two ends, or to the south pole of another magnet in the same group of magnets.
[0056] In one embodiment, the piezoelectric actuators are electrically connected to the switching power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the switching power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by the switching power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
[0057] In one embodiment, the piezoelectric actuators are electrically connected to the switching power supply with a capacitive connection, such that a first capacitive surface electrically connected to at least one of the piezoelectric actuators forms a first terminal of a capacitor, and a second capacitive surface electrically connected to the switching power supply forms a second terminal of the capacitor, the first and second terminals separated by a gap, such that when the second capacitive surface is energized by the switching power supply, a current is induced in the first capacitive surface, energizing at least one piezoelectric actuator.
.. [0058] In one embodiment, the electric stepper motor further comprises f) a rotary position sensor which can detect an absolute rotary position of the mobile assembly.
[0059] In one embodiment, the rotary position sensor is operably attached to the frequency controller such that the frequency controller can use the absolute rotary position of the mobile assembly to determine when to switch the switching power supply on and off such that the .. mobile assembly moves the target fixed distance.
Date Recue/Date Received 2022-02-28 [0060] Generally, among the many objectives of the present disclosure is the provision of an electric motor with positional sensing. One objective is the provision of an electric motor with positional sensing which uses piezoelectric impulse and permanent magnets as a source of generating mechanical energy from electrical energy. Another objective is the provision of an electric motor with positional sensing which does not use electromagnets and is therefore more efficient and economical to construct. Another objective is the provision of an electric motor with positional sensing which does not use electromagnets and is therefore more efficient and economical to operate. Yet another objective is the provision of an electric motor with positional sensing which does not use electromagnets and is therefore more durable and easier to maintain. Still another objective is the provision of an electric motor with positional sensing which does not use electromagnets and is therefore lighter in weight than a traditional brushless electric motor of equivalent output. The disclosure also provides an electric motor with positional sensing which does not require external detection means and produces a precise measurement of the position and/or motion of the motor. Other advantages and objectives of the electric motor with positional sensing will become clear by reading the application and the disclosures herein.
[0061] In accordance with another aspect of the present disclosure, there is provided an electric motor with positional sensing comprising: a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply; b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets; c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes; d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and e) a counting device, which counts a number of times that one or more of the Date Recue/Date Received 2022-02-28 actuator magnets passes by one or more of the response magnets in turn from a known starting position, such that a relative position of the mobile assembly relative to the known starting position can be determined by using a ratio of an angle swept by a single actuator magnet or a single response magnet to a total diameter of the static assembly, the counting device being able to count the number of times whether the mobile assembly moves relative to the static assembly due to the plurality of piezoelectric actuators being energized by the power supply or due to an external load which imparts an external torque onto one or both of the static assembly or the mobile assembly.
[0062] In one embodiment, the counting device counts the number of times by detecting a back-current when the piezoelectric actuators are not energized by the power supply, the back current caused by the piezoelectric actuators being compressed as the actuator magnets move relative to the response magnets due to the external torque.
[0063] In one embodiment, the group of response magnets comprises a single piece of magnetic material, the single piece of magnetic material having a plurality of magnetic regions, each magnetic region having a local north pole and a local south pole.
[0064] In one embodiment, the electric motor with positional sensing comprises f) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0065] In one embodiment, there are two groups of piezoelectric actuators, further comprising:
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators forming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
[0066] In one embodiment, the electric motor with positional sensing comprises g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and Date Recue/Date Received 2022-02-28 mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0067] In one embodiment, each group of actuator magnets has two ends, and the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group .. of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
[0068] In one embodiment, actuator magnets in each group of actuator magnets are secured by an adhesive, the adhesive securing the actuator magnets in a fixed orientation.
[0069] In one embodiment, there are two groups of piezoelectric actuators, further comprising:
f) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and g) a second group of piezoelectric actuators forming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
[0070] In one embodiment, each group of actuator magnets has two ends, and the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
[0071] In one embodiment, the actuator magnets in each group of actuator magnets are secured by an adhesive, the adhesive securing the actuator magnets in a fixed orientation.
Date Recue/Date Received 2022-02-28 [0072] In one embodiment, the electric motor with positional sensing further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0073] In one embodiment, the electric motor with positional sensing further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0074] In one embodiment, the electric motor with positional sensing further comprises f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0075] In one embodiment, the electric motor with positional sensing further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0076] In one embodiment, the piezoelectric actuators are electrically connected to the power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by Date Recue/Date Received 2022-02-28 the power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
[0077] In accordance with another aspect of the present disclosure, there is provided an electric motor with positional sensing comprising: a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply; b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets; c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes; d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and e) an induced-current sensor, which detects a back-current, the back-current being induced in the piezoelectric actuators when due to an external load imparting an external torque onto one or both of the static assembly or the mobile assembly, the mobile assembly moves relative to the static assembly.
[0078] In one embodiment, the electric motor with positional sensing further comprises f) a calibration memory device, which can store a plurality of calibration back-current values, the calibration back-current values obtained by using the induced-current sensor to measure the back-current at a plurality of times.
[0079] In one embodiment, the electric motor with positional sensing further comprises g) a calibration load, the calibration load comprising an external driving device which can be removably connected to the electric motor to impart a controllable external torque onto one or the other of the mobile assembly or the static assembly.
Date Recue/Date Received 2022-02-28 [0080] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply.
[0081] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply.
[0082] In one embodiment, the electric motor with positional sensing further comprises g) a position determining device, the position determining device dynamically receiving a plurality of operating back-current values from the induced-current sensor, the position determining device comparing the plurality of operating back-current values to the plurality of calibration back-current values to determine a relative position of the mobile assembly to the static assembly.
[0083] In one embodiment, the electric motor with positional sensing further comprises h) a position determining device, the position determining device dynamically receiving a plurality of operating back-current values from the induced-current sensor, the position determining device comparing the plurality of operating back-current values to the plurality of calibration back-current values to determine a relative position of the mobile assembly to the static assembly.
[0084] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply, and the position determining device compares the first plurality of calibration back-current values and the second plurality of calibration values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
[0085] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the Date Recue/Date Received 2022-02-28 piezoelectric actuators are energized by the power supply, and the position determining device compares the first plurality of calibration back-current values and the second plurality of calibration values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
[0086] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply, and the first plurality of calibration back-current values and the second plurality of calibration back-current values are combined into a plurality of average calibration back-current values, and the position determining device compares the plurality of average calibration back-current values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
[0087] In one embodiment, the electric motor with positional sensing further comprises a) a group of elastic members, the elastic members mechanically affixed to at least one of the static or mobile piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0088] In one embodiment, the electric motor with positional sensing further comprises f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0089] In one embodiment, each group of static magnets and/or each group of mobile magnets is a group of magnets containing at least two magnets, and each group of magnets has two ends, and the magnets in each group of magnets overlap each other to produce a combined magnetic field, and each of the magnets in a group of magnets has a north pole and a south Date Recue/Date Received 2022-02-28 pole, and the south pole of any particular magnet is either physically proximate to one of the two ends, or to the north pole of another magnet in the same group of magnets, and the north pole of any particular magnet is either physically proximate to one of the two ends, or to the south pole of another magnet in the same group of magnets.
[0090] In one embodiment, the piezoelectric actuators are electrically connected to the power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by the power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
BRIEF DESCRIPTION OF THE FIGURES
[0091] Several embodiments of the present disclosure will be provided, by way of examples only, with reference to the appended drawings, wherein:
[0092] FIGURE 1 depicts a perspective view of a magnetic bearing, in accordance with one aspect of the disclosure;
[0093] FIGURE 2 depicts an overhead view of a first alternate embodiment of the magnetic bearing depicted in Figure 1;
[0094] FIGURE 3 depicts a cutaway perspective view of the first alternate embodiment of the magnetic bearing depicted in Figure 2;
[0095] FIGURE 4 depicts a detail view of the interfacing stator and rotor elements of the first alternate embodiment of the magnetic bearing depicted in Figures 2 and 3;
[0096] FIGURE 5 depicts an exploded perspective view of the first alternate embodiment magnetic bearing assembly depicted in Figures 2 to 4;
[0097] FIGURE 6 depicts an overhead view of a second alternate embodiment of the magnetic bearing depicted in Figure 1;
Date Recue/Date Received 2022-02-28 [0098] FIGURE 7 depicts an exploded perspective view of the second alternate magnetic bearing assembly depicted in Figure 6;
[0099] FIGURE 8 depicts an alternate exploded perspective view of the second alternate magnetic bearing assembly depicted in Figures 6 and 7;
[00100] FIGURE 9 depicts a cutaway view of the second alternate magnetic bearing assembly depicted in Figures 6 to 8;
[00101] FIGURE 10 depicts a perspective view of a third alternate embodiment of the magnetic bearing depicted in Figure 1;
[00102] FIGURE 11 depicts a cross-sectional perspective view of the third alternate embodiment of the magnetic bearing depicted in Figure 10;
[00103] FIGURE 12 depicts a perspective view of an electric stepper motor, in accordance with another aspect of the disclosure;
[00104] FIGURE 13 depicts an overhead view of a first alternate embodiment of the electric stepper motor depicted in Figure 12;
[00105] FIGURE 14 depicts a cutaway perspective view of the first alternate embodiment of the electric stepper motor depicted in Figure 13;
[00106] FIGURE 15 depicts a detail view of the interfacing stator and rotor elements of the first alternate embodiment of the electric stepper motor depicted in Figures 13 and 14;
[00107] FIGURE 16 depicts an exploded perspective view of the first alternate embodiment electric stepper motor assembly depicted in Figures 13 to 15;
[00108] FIGURE 17 depicts an overhead view of a second alternate embodiment of the electric stepper motor depicted in Figure 12;
[00109] FIGURE 18 depicts an exploded perspective view of the second alternate electric stepper motor assembly depicted in Figure 17;
[00110] FIGURE 19 depicts an alternate exploded perspective view of the second alternate electric stepper motor assembly depicted in Figures 17 and 18;
Date Recue/Date Received 2022-02-28 [00111] FIGURE 20 depicts a cutaway view of the second alternate electric stepper motor assembly depicted in Figures 17 to 19;
[00112] FIGURE 21 depicts a perspective view of a third alternate embodiment of the electric stepper motor depicted in Figure 12;
[00113] FIGURE 22 depicts a cross-sectional perspective view of the third alternate embodiment of the electric stepper motor depicted in Figure 21;
[00114] FIGURE 23 depicts a perspective view of an electric motor with positional sensing in accordance with another aspect of the disclosure;
[00115] FIGURE 24 depicts an overhead view of a first alternate embodiment of the electric motor with positional sensing depicted in Figure 23;
[00116] FIGURE 25 depicts a cutaway perspective view of the first alternate embodiment of the electric motor with positional sensing depicted in Figure 24;
[00117] FIGURE 26 depicts a detail view of the interfacing stator and rotor elements of the first alternate embodiment electric motor with positional sensing depicted in Figures 24 and 25;
[00118] FIGURE 27 depicts an exploded perspective view of the first alternate embodiment electric motor with positional sensing assembly depicted in Figures 24 to 26;
[00119] FIGURE 28 depicts an overhead view of a second alternate embodiment of the electric motor with positional sensing depicted in Figure 23;
[00120] FIGURE 29 depicts an exploded perspective view of the second alternate electric motor with positional sensing assembly depicted in Figure 28;
[00121] FIGURE 30 depicts an alternate exploded perspective view of the second alternate electric motor with positional sensing assembly depicted in Figures 28 and 29;
[00122] FIGURE 31 depicts a cutaway view of the second alternate electric motor with positional sensing assembly depicted in Figures 28 to 30;
Date Recue/Date Received 2022-02-28 [00123] FIGURE 32 depicts a perspective view of a third alternate embodiment of the electric motor with positional sensing depicted in Figure 23; and [00124] FIGURE 33 depicts a cross-sectional perspective view of the third alternate embodiment of the electric motor with positional sensing depicted in Figure 32.
[00125] In the figures, like reference numerals denote like parts unless the contrary is indicated, as will become apparent from the detailed description.
[00126] Elements in the several figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be emphasized relative to other elements for facilitating understanding of the various presently disclosed embodiments. Also, common, but well-understood elements that are useful or necessary in commercially feasible embodiments are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present disclosure.
DETAILED DESCRIPTION
[00127] Various implementations and aspects of the specification will be described with reference to details discussed below. The following description and drawings are illustrative of the specification and are not to be construed as limiting the specification.
Numerous specific details are described to provide a thorough understanding of various implementations of the present specification. However, in certain instances, well-known or conventional details are not described in order to provide a concise discussion of implementations of the present .. specification.
[00128] Reference will now be made in detail to several embodiments of the disclosure that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms such as top, bottom, left, right, up, down, over, above, below, beneath, rear, and front, can be used with respect to the drawings. These and similar directional terms are not to be construed to limit the scope of the disclosure in any manner. The words attach, connect, couple, and similar terms with their inflectional Date Recue/Date Received 2022-02-28 morphemes do not necessarily denote direct or intermediate connections, but can also include connections through mediate elements or devices.
[00129] It should be noted that the sizes and configurations of the preferred embodiment(s) described in the drawings are exaggerated for clarity of disclosure: in actual practice, the tolerances between the elements of embodiments of the disclosure would be much more precise. It is a feature of the disclosure that it allows such very precise tolerances.
[00130] Various aspects of this application include magnetic bearings and electric motors, which will now be described.
MAGNETIC BEARING
[00131] In acccordance with one aspect of the disclosure, a magnetic bearing 10 will now be described in terms of a brushless electric motor such as is disclosed in U.S. Patent Application No. 16/941,477 filed July 28, 2020. The distinction between such a brushless electric motor and a magnetic bearing, in the context of this application, is that the bearing is active even when the motor is not energized, with these additional features:
[00132] If and when the load cannot be rotated at a desired rate by an external driving force, the piezoelectric actuators can be powered to add additional torque and serve as an auxiliary source of power.
[00133] If and when the load begins to rotate faster than is desired, the piezoelectric actuators can be powered to provide torque in the opposite direction of rotation, slowing the rotation of the load.
[00134] The piezoelectric actuators can be used to stabilize the spin of the load without adding any net torque or "drive."
[00135] The piezoelectric actuators can be used to recover some of the energy from the rotation of the load as they will provide a current if the load rotates freely.
[00136] For purposes of this aspect of the disclosure, piezoelectric actuators are described as being "electrically connected" to a power supply. Such a connection can be made via physical conductors (wires, PCB conductive paths, conductive inks, et cetera) or by any Date Recue/Date Received 2022-02-28 other reasonable means that allows the power supply to supply energy to the piezoelectric actuators and causes the piezoelectric effect to change the dimensions of the piezoelectric actuators. This includes, but is not limited to, electromagnetic induction or transfer by capacitance. It is required that the means of electrical connection be able to switch the .. piezoelectric actuators on and off and/or apply a current flow in one direction and then in the other direction fast enough to allow the motor to operate, as will be made clear in the specification below. This will be referred to generally as "rise" time ¨ the period of time it takes to energize the piezoelectric actuator and/or the capacitator powering it ¨ and the "fall"
time ¨ the period of time it takes to deenergize the piezoelectric actuator and/or the capacitor powering it.
[00137] For purposes of this aspect of the disclosure, the magnetic bearing, as embodied in a "motor," will generally have a group of components which remains static relative to a load, and a second group of components which will move relative to the first group of components.
The first group of components will be referred to collectively as a stator assembly, and the second group referred to collectively as a rotor assembly. Prefixing a component with the word "rotor" or "stator" indicates which group of components it belongs to in the embodiment/configuration which is currently being described. Piezoelectric actuators in the stator assembly are stator piezoelectric actuators (or simply stator actuators) and magnets affixed to stator piezoelectric actuators are stator magnets, and vice versa with regard to the rotor assembly.
[00138] At the same time, for purposes of this aspect of the disclosure, magnets can also be described as falling into one or both of two distinct types independent of whether they are part of the stator assembly or the rotor assembly. Actuator magnets are magnets which have/are having force imposed upon them by a piezoelectric actuator. Response magnets are magnets which have/are having force imposed upon them via magnetic field interactions with actuator magnets. If only one group of magnets is affixed to piezoelectric actuators, those are the actuator magnets, and the rest of the magnets in the motor are response magnets. If multiple groups of magnets are affixed to piezoelectric actuators, magnets affixed to a piezoelectric actuator which is being energized and causing it to impose force on those magnets are actuator magnets, and magnets which are not so affixed, or which are affixed to a piezoelectric actuator which is not being energized, are response magnets. It is possible for any given magnet to be an actuator magnet or a response magnet or both at any given time depending on the bearing Date Recue/Date Received 2022-02-28 controller's configuration and energization of the piezoelectric actuators. A
rotor magnet or a stator magnet may at any time be an actuator magnet, a response magnet, or both.
[00139] By referring to FIGURE 1, the basic nature of the magnetic bearing 10 can be easily understood. Outer rotor housing 11 surrounds optional mechanical bearing 12 which is free to rotate on balls 13, which bear the load between the motor and whatever it is mounted in and whatever it is driving.
[00140] It should be clearly understood that in the primary configuration of the magnetic bearing, the mechanical bearing elements (12 and 13) are provided only for supplemental bearing capability. They are not required. The magnetic bearing can function without them.
[00141] Inner rotor element 14 has multiple rotor magnets 15 having rotor north poles 15a and rotor south poles 15b. Any suitable magnet may be used for rotor magnets 15, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare-earth magnetic particles. Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00142] Stator assembly 19 consists of central hub 18, which supports multiple stator piezoelectric actuators 17. Stator piezoelectric actuators 17 have a magnet mount end 17a and a hub end 17b. Stator piezoelectric actuators 17 are connected to a switching power supply (not shown) which can energize the stator piezoelectric actuators at any reasonable driving frequency. When the stator piezoelectric actuators are energized, they expand, using the principle of piezoelectric expansion, also known as the piezoelectric effect, which is well known to persons of ordinary skill in the art. Stator piezoelectric actuators 17 are constructed so that their expansion is along their long axes: in other words, when the stator piezoelectric actuators are energized, the distance between magnet mount end 17b and hub end 17a increases.
[00143] Mounted to magnet mount ends 17b are stator magnets 16, having stator north poles 16a and stator south poles 16b. Any suitable magnet may be used for stator magnets 16, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare- earth magnetic particles. Electromagnets may also be Date Recue/Date Received 2022-02-28 used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00144] It is strongly preferred that the rotor magnets and the stator magnets have the same poles (north and north or south and south) in opposition at their closest points (as shown) but with proper configuration, it is possible to practice the invention with the rotor magnets and the stator magnets having opposite poles (north and south or south and north) in opposition.
If opposite poles are put into opposition, the motor may require an external initiating force and/or the stator piezoelectric actuators may be required to be energized in a staggered sequence. If reversible electromagnets are used for either the rotor magnets, the stator magnets, or both, the question of initial polarities is unimportant.
[00145] The preferred embodiment pictured in FIGURE 1 shows the invention ready to be practiced. The magnetic forces from the rotor magnets and the stator magnets are at a point of equilibrium where the magnets are in the lowest possible potential energy state with regard to the magnetic repulsion between the rotor magnets and the stator magnets.
Inner rotor element 14 will, absent the addition of energy from some exterior source, remain at this point of equilibrium indefinitely.
[00146] To practice this aspect of the disclosure, when a torque of some sort is imposed on the rotor assembly, the rotor may rotate, but the rotor magnets and the stator magnets will .. continue to repel each other, and a controlled, friction free rotation is provided by the bearing.
It should be noted that the components in FIGURE 1 are greatly simplified:
while the bearing as shown in FIGURE 1 would function, in practice the magnetic bearing would have far fewer gaps between the individual rotor magnets and the individual stator magnets (see e.g. FIGURE
6.) [00147] When additional control or torque ¨ either in the same direction of current rotation or opposed to the current rotation ¨ is required, stator piezoelectric actuators 17 are energized. This causes the distance between hub end 17b and magnet mount end 17a to increase, pushing stator magnet 16 closer to rotor magnet 15. This increases the magnetic repulsion between the rotor magnet and the stator magnet, disturbing the equilibrium between them.
Date Recue/Date Received 2022-02-28 [00148] The switching power supply is controlled by a frequency controller (not shown) which causes it to energize and de-energize stator piezoelectric actuators 17 at a frequency which maintains optimal rotational characteristics for the magnetic bearing.
Additional sensors can be linked to the frequency controller to enable such control. For instance, and without limiting the possible control means and methods:
[00149] If transient accelerations are detected, the frequency controller could energize those piezoelectric actuators on the appropriate side of the bearing to push the rotor back into a more centralized orientation, resisting the transient diametric accelerations; and/or [00150] If excessive heat is detected, the frequency controller could de- energize the piezoelectric actuators to increase the overall gap between the stator magnets and the rotor magnets, allowing more air to flow through the gap and provide additional cooling; and/or [00151] If the stator or rotor elements are detected to have expanded or contracted due to thermal changes, the frequency controller could energize or de-energize the piezoelectric actuators as needed to maintain a target gap between the rotor magnets and the stator magnets.
[00152] As is apparent, if desired the frequency controller can energize and de-energize the piezoelectric actuators in ways which can convert magnetic potential energy into rotational energy and accelerate or decelerate inner rotor element 14 in a rotational fashion. It is preferred, but not required, that sensors (not shown) be operably connected to the inner rotor element or otherwise be able to detect its angular velocity, and communicate it to the frequency controller such that the frequency controller can adjust the driving frequency to increase or decrease the force exerted by the stator magnets on the rotor magnets and thus either increase the speed of rotation (under constant load,) increase the applied torque (under increasing load,) or both.
[00153] If such sensors are used, the invention can also be used as an extremely precise stepper motor and/or rotational position sensor. It is preferred, but not required, that a sensor allowing absolute rotational position data also be incorporated into the invention if such a usage is desired. This allows the frequency controller to know where the inner rotor element is at the beginning and the end of a step cycle.
[00154] Once the equilibrium between the rotor magnets and the stator magnets is disturbed, the system will have more magnetic potential energy than before, which will cause Date Recue/Date Received 2022-02-28 the rotor magnets to exert a force on inner rotor 14. Inner rotor element 14 is free to rotate, so it will rotate in one direction or the other as impelled by the balance of forces. As will be shown in later figures, control of the shape and orientation of the rotor magnets and/or stator magnets will allow for a preferred direction of rotation.
[00155] Although the preferred embodiment is described as a magnetic bearing, which is designed to provide a highly controllable magnetic bearing between a load and a fixed base, it will be apparent to persons of ordinary skill in the art that since the piezoelectric effect works both ways ¨ electrical potential can be turned into mechanical force, and mechanical force can be turned into electrical potential ¨ that the preferred embodiment can also serve as a generator of electrical power if an external load forces the inner rotor element to rotate against the magnetic force attempting to hold it in equilibrium. Similarly, the preferred embodiment can also be used as a drive motor which also provides regenerative braking by switching from power in (during drive mode) to power out (during regenerative braking mode.) All of the alternate configurations/embodiments/methods of practice described in this paragraph are applicable to all of the embodiments of the invention disclosed in this application.
[00156] FIGURE 2 shows a first alternate embodiment of the magnetic bearing. The first alternate embodiment of the magnetic bearing works in the same general fashion as the embodiment of FIGURE 1, except where noted otherwise. It likewise would incorporate a switching power supply, frequency controller, and could incorporate sensors, et cetera.
[00157] Magnetic bearing 20 incorporates rotor piezoelectric actuators 27b, analogous to stator piezoelectric actuators 17 in FIGURE 1. Magnetic bearing 20 also incorporates stator piezoelectric actuators 27a. It is neither preferred nor required for either configuration to be applied with a single (inner and outer) group of piezoelectric actuators or a double (inner and outer) group of piezoelectric actuators: the two configurations are shown for clarity of disclosure.
[00158] When either stator piezoelectric actuators 27a or rotor piezoelectric actuators 27b are energized, rotor magnets 25 are pushed toward stator magnets 26, and as in FIGURE
1, magnetic repulsion is increased, incurring a force against the rotor piezoelectric actuators.
As the rotor piezoelectric actuators are affixed to outer casing 21, which is free to rotate relative to hub 29 on optional mechanical bearing 52 (not identified, see FIGURE 5) which includes Date Recue/Date Received 2022-02-28 race 22 containing balls 23, balls 23 bearing the load and allowing rotation of rotary center bearing element 24 relative to fixed center bearing element 28.
[00159] As with the previous embodiment, the elements of mechanical bearing 52 are optional. They are not required, and the magnetic bearing will function without them. They could also serve as a secondary bearing if for whatever reason it was desired that the hub elements could rotate independenly of the rotor elements. It is optional, if such a mechanical bearing is incorporated into the invention, to add mechanical or electrical features that allow it to only rotate in one direction. This would create a mechanical lock between the rotor elements and the hub elements such that the rotor could drive the hub if the rotor is rotating in the same direction as the hub, but if the magnetic bearing fails in such a way as to prevent the magnetic bearing from rotating, the hub elements would be free to rotate and come to a controlled stop, minimizing damage to the magnetic bearing assembly.
[00160] Depending on the desired method of operation, the stator piezoelectric actuators can be activated in concert with the rotor piezoelectric actuators, or only one or the other group of piezoelectric actuators can be active at any given time. If using the magnetic bearing to accelerate or decelerate the load, activating both at once can be used to increase torque/rotational velocity, whereas activating only one or the other can be used for lower output modes. Alternatively, one group of piezoelectric actuators can be wired to deliver input power (motor driving) and the other group wired to receive output power (generation/regenerative braking.) The groups of piezoelectric actuators can also be wired such that some of the actuators in each group are preferentially used to deliver input power and some are preferentially used to receive output power. Finally, all or fewer than all of the piezoelectric actuators in a particular group can be active at any given time to deliver any particular desired amount of input power or receive any particular desired amount of output power, allowing an additional means of controlling power flow and/or reducing electrical fatigue on the individual components as they are cycled in and out of service.
[00161] FIGURE 3 shows the first alternate embodiment in cutaway form.
Magnetic bearing 20, having the same components as in FIGURE 2, is surrounded by backing plate 33 and housing 31, while hollow shaft 32, which is operably affixed to hub 29 (see FIGURE 2) and/or rotary center bearing element 24, allows either delivery of mechanical rotational energy Date Recue/Date Received 2022-02-28 (motor mode) or input of mechanical rotational energy (generation/regenerative braking mode.) [00162] FIGURE 4 shows a pair of opposing piezoelectric actuators and their corresponding magnets in detail. Stator piezoelectric actuator 27b is affixed to stator magnet .. 25 which has stator north pole 25a and stator south pole 25b. Rotor piezoelectric actuator 27a is affixed to rotor magnet 26 which has rotor north pole 26a and rotor south pole 27a. It is preferred, but not required, that the rotor magnets and the stator magnets be asymmetrical to each other (that is, the rotor magnets are not symmetrical with the stator magnets, shown here as their being different sizes) to make it easier to overcome the tendency of the system to "lock"
into a position of minimized magnetic potential energy. Since the magnets are not symmetrical, when they are moved in relation to each other the corresponding magnetic fields will tend to push more in one direction than the other, overcoming such locking symmetry.
[00163] FIGURE 5 shows a more complete assembly of the first alternate embodiment of the invention for clarity of disclosure. Axial bolt 51 holds the assembly together and keeps the rotary elements on-center. Bearing 52 incorporates rotary center bearing element 24, race 22, balls 23, and fixed center bearing element 28. (See FIGURE 2 for more detail.) [00164] FIGURE 6 shows a second alternate embodiment of the magnetic bearing with a more complex configuration of rotor magnets and stator magnets. This configuration, while not required, is somewhat preferred as it provides multiple benefits to the practice of the invention at the price of higher complexity and cost of manufacture.
[00165] Magnetic bearing 60 comprises rotor assembly 614 and stator assembly 618.
Rotably affixing the rotor assembly to the stator assembly is bearing 652 which rotates around central point 611. Mechanically affixed to bearing 652 are one or more stator piezoelectric elements.
[00166] As with the previously described embodiments, the elements of mechanical bearing 652 are optional. They are not required, and the magnetic bearing will function without them.
[00167] Shown is a configuration with six such stator piezoelectric elements including stator piezoelectric element 619. Mechanically affixed to the stator piezoelectric elements are Date Recue/Date Received 2022-02-28 stator magnet elements such as stator magnet element 640. The stator magnet elements comprise one or more magnets having a north pole and a south pole, such as stator magnet 617 having stator magnet north pole 617a and stator magnet south pole 617b. There is a gap between the stator magnet elements and one or more rotor magnet elements.
Shown is a configuration with six such rotor magnet elements including rotor magnet element 642. Each rotor magnet element includes one or more rotor magnets such as rotor magnet 616, which has rotor magnet north pole 616a and rotor magnet south pole 616b.
[00168] It is not required that each rotor magnet element be exactly geometrically opposed to a stator magnet element at any particular time during operation or non-operation and in fact it is likely that the equilibrium during non-operation will result in some degree of offset. It is strongly preferred that there be a rotor magnet element for each stator magnet element, and vice versa. It is required that there be a gap between the rotor magnet elements and the stator magnet elements sufficient to allow the rotor magnet elements to move freely without contacting the stator magnet elements under any reasonable amount of bearing load, rotary speed, or transient vibratory load.
[00169] Although the configuration of magnets shown will be inherently stable due to magnetic attraction between the individual magnets, it is preferred that the magnets in each rotor magnet element and stator magnet element be epoxied or otherwise physically affixed to each other to maintain the desired alignment and prevent shifting under load or due to vibration or other transient phenomena.
[00170] It is strongly preferred, but not required, to use an overlapping configuration of magnets as shown in the rotor magnet elements and the stator magnet elements as this will minimize asymmetries in the overall magnetic field structure in the brushless magnetic motor.
[00171] FIGURE 7 shows a more complete assembly of the second alternate embodiment of the invention for clarity of disclosure along with the addition of an optional set of stator piezoelectric actuators as in FIGURE 2. (See FIGURE 6 for more detail.) Axial bolt 651 holds the assembly together and keeps the elements on-center. Capacitor array bolts 680 affix capacitor array 656 to base element 682 by means of threaded receivers 681. Although shown as traditional capacitive plates, any desired means of capacitive induction of current, such as vacuum-tube capacitors, can be used.
Date Recue/Date Received 2022-02-28 [00172] For purposes of this description, it is assumed that base element 682 is secured to something which is designated as static and therefore base element 682 forms part of a stator assembly. For example, if motor 60 were to be used to bear the load of the wheel of an electric vehicle, base element 682 would ultimately be statically affixed to the chassis of the vehicle, whereas housing 612 would ultimately be statically affixed to the wheel of the vehicle.
[00173] Capacitor array 680, which does not rotate relative to the stator assembly, includes capacitor plates such as capacitor plate 658, each capacitor plate separated by a gap such as capacitor gaps 657a and 657b. Capacitor array energizes rotor piezoelectric array 621, which includes one or more rotor piezoelectric actuators such as rotor piezoelectric actuator 621. The rotor piezoelectric actuators are mechanically affixed to one or more (optional) rotor magnet brackets 678, each rotor magnet bracket having a rotor circumferential surface 662, and (optional) rotor vertical guides 661a and 661b, with all of the rotor magnet brackets forming rotor magnet bracket assembly 660.
[00174] Mechanically affixed to the rotor piezoelectric actuators, either directly or via the (optional) rotor magnet brackets, are one or more rotor magnet elements such as rotor magnet element 642, each rotor magnet element comprising one or more rotor magnets such as rotor magnet 616, with all of the rotor magnet elements forming rotor magnet assembly 672.
[00175] During active operation of the piezoelectric actuators, the rotor piezoelectric actuators are energized, causing them to expand toward the center of motor 60 (since they cannot expand against the fixed position of the rest of the rotor assembly including ultimately housing 612) pushing the rotor magnet elements toward the stator magnet elements (see below) and imparting a magnetic force as explained in previous descriptions (see FIGURES 1, 2, and 6.) The rotor piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The rotor piezoelectric actuators can be energized without energizing the stator piezoelectric actuators (see below) or in concert with them.
[00176] Rotor magnet assembly 672 radially surrounds stator magnet assembly 670, the rotor magnet assembly separated from the stator magnet assembly by a gap (NOT
SHOWN, see FIGURE 9.) Stator magnet assembly 670 comprises one or more stator magnet elements such as stator magnet element 640, each stator magnet element comprising one or more stator Date Recue/Date Received 2022-02-28 magnets such as stator magnet 617. Stator magnet elements are mechanically affixed to stator piezoelectric assembly 669, which includes one or more stator piezoelectric actuators such as stator piezoelectric actuator 619, either directly or by means of (optional) stator magnet bracket assembly 655. (Optional) stator magnet bracket assembly 655 comprises one or more stator magnet brackets such as stator magnet bracket 676, each stator magnet bracket including a stator circumferential surface such as stator circumferential surface 654 and (optional) stator vertical guides 653a and 653b.
[00177] When energized, the stator piezoelectric actuators expand toward the outer circumference of motor 60 (since they cannot expand toward the fixed position of the rest of the stator assembly) pushing the stator magnet elements toward the rotor magnet elements and imparting a magnetic force as explained in previous descriptions (see FIGURES
1, 2, and 6.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632. The stator piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The stator piezoelectric actuators can be energized without energizing the rotor piezoelectric actuators or in concert with them.
[00178] FIGURE 8 shows the configuration of FIGURE 7 in an alternate phase of assembly for clarity of disclosure. Housing 612 is ready to be placed over the rest of the motor assembly, with capacitor array 656 ready to be secured to base element 682 with capacitor array bolts 680. The rotor and stator elements are assembled, for example rotor piezoelectric actuator affixed to rotor circumferential surface 662 and stator piezoelectric actuator affixed to stator circumferential surface 654, and both ready to be inserted into their respective assemblies.
[00179] FIGURE 9 shows the configuration of FIGURE 7 in a cutaway view for clarity of disclosure. Housing 612 is axially secured by axial bolt 651 but is free to rotate relative to base element 682 as they are mechanically connected only by bearings 652 and 683. Rotor magnet element 642 is separated from stator magnet element 640 by gap 690. The size of gap 690 can be changed by energizing stator piezoelectric actuator 619 and/or rotor piezoelectric actuator 621. As the piezoelectric actuators change the size of gap 690, the relative orientation of the magnetic fields of the rotor magnet elements and the stator magnet elements will change.
This will cause magnetic force to be exerted between magnet elements, but as only the rotor Date Recue/Date Received 2022-02-28 magnet elements (ultimately connected to housing 612) can move, the force will cause housing 612 to move, allowing rotary motion to be imparted to hollow shaft 632 and thus to an axle, a wheel, or any other rotary member or rotary load desired.
[00180] FIGURE 10 shows a third alternate embodiment of this aspect of the invention.
In this embodiment, rather than a plurality of distinctive magnets, the rotor magnets comprise a single piece of rotor magnetic material, which is structured to have a plurality of magnetic regions, each magnetic region having a north pole and a south pole. Similarly, there are two individual pieces of stator magnetic material having a plurality of magnetic regions. Each piece of stator magnetic material is attached to one end of a single piezoelectric actuator.
[00181] Magnetic bearing 80 comprises rotor assembly 82, stator magnet assemblies 84 and 87, and piezoelectric actuator 810 which is operably affixed to PCB 92 (NOT SHOWN:
See FIGURE 11.) Rotor assembly 82, which is free to rotate relative to all stator assembly components and is attached to whatever rotational load (NOT SHOWN) it is desired to bear with the bearing, is comprised of magnetic material (or can have an inner section of magnetic material surrounded by non-magnetic material as desired) which has magnetic regions, each magnetic region having a north pole and a south pole such as rotor north poles 82a and 82b and rotor south poles 83a and 83b. Opposite the rotor assembly's magnetic material, separated by a gap (See FIGURE 11) are stator magnet assemblies 84 and 87. It is possible to construct this embodiment of the invention with a single stator magnet assembly, but it is strongly preferred to use two symmetrical stator magnet assemblies as shown for purposes of balance and to maximize the piezoelectric actuator's efficiency. First stator magnet assembly 84, similarly to rotor section 82, is composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and rotor south poles 86a and 86b. Second stator magnet assembly 87, is likewise composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and stator south poles 86a and 86b.
[00182] FIGURE 11 shows a cutaway view of the third alternate embodiment of this aspect of the invention for additional clarity of disclosure. Magnetic bearing 80 has gap 91, which separates the various stator and rotor assemblies (see FIGURE 10) and allows the magnetic bearing to serve as a no-contact magnetic bearing so long as the planar load does not Date Recue/Date Received 2022-02-28 materially affect the gap as maintained by the magnet assembly and the stator magnet assemblies. This is an additional advantage of several of the embodiments and configurations of the invention disclosed herein. PCB 92 is a printed circuit board which is both mechanically and electrically affixed to piezoelectric actuator 810 and provides it with electrical potential from a switching power supply (NOT SHOWN).
[00183] If necessary, fluid can be forcibly circulated around the assemblies or even through the gap to cool the motor, but as many piezoelectric devices actually work better when they reach a relatively high operating temperature, the need for cooling will be minimal in many applications. This is another advantage of the invention. It is required that for all embodiments and configurations of the invention, that operating temperatures be kept low enough to avoid demagnetization of any permanent magnets which are used. This will vary as various kinds of magnetic material have different demagnetization thresholds.
(For example, some ferrite magnets can tolerate temperatures up to 250 C, whereas some rare-earth magnets can only tolerate temperatures up to 100 C.) [00184] To practice an embodiment of this aspect of the invention, an electrical potential is put across piezoelectric actuator 810, which is electrically connected to PCB 92. This causes piezoelectric actuator 810 to expand along its long axis, changing the relative position of the stator magnet assemblies and the rotor assembly. This in turn causes electromagnetic force to be exerted on the rotor assembly, which will rotate to a position which will minimize the magnetic potential energy between the rotor assembly and the stator assemblies. The electrical potential across piezoelectric actuator 810, is then removed and/or reversed, causing it to contract along its long axis, again changing the relative position of the various magnet assemblies. A switching power supply (NOT SHOWN) continuously cycles the electrical potential across the piezoelectric actuator to produce the desired magnetic bearing load and/or acceleration or deceleration as in previously described embodiments.
[00185] It is optional, but neither preferred nor required, for either the rotor assembly or the stator assembly, or both, to comprise multiple magnets as in earlier described configurations. (See FIGURE 1, FIGURE 2, and/or FIGURE 6.) So long as the rotor assembly and the stator assembly are configured as shown, the configuration of this third alternate embodiment incorporating a single piezoelectric actuator will function and provide the benefits of the invention.
Date Recue/Date Received 2022-02-28 [00186] Alternate configurations of this aspect of the disclosure, which can be applied to any of the described embodiments, will now be disclosed.
[00187] In a first alternate configuration of this aspect (NOT SHOWN) some or all of the rotor magnets, or some or all of the stator magnets, of either the preferred embodiment or the first alternate embodiment are replaced with electromagnets.
[00188] In a second alternate configuration of this aspect (NOT SHOWN) one or more elastic members is fitted into the motor assembly such that the piezoelectric actuators are working against the elastic members when they are energized, compressing them and creating elastic potential energy, so that when the piezoelectric actuator(s) is/are de-energized, the magnet(s) affixed to the piezoelectric actuator(s) return to their prior position more quickly and without the need to impose a reverse polarity potential across the piezoelectric actuator when the elastic potential energy provides impetus to the piezoelectric actuators.
[00189] In a third alternate configuration of this aspect (NOT SHOWN), the features of the first and second configurations are combined.
[00190] It will be apparent to those of ordinary skill in the art that while the invention and its preferred embodiments are described in terms of rotary bearings, the principles taught by the invention can be used to create linear bearings, such as reciprocating bearings, by using the basic principle of piezoelectric motivation of opposing magnetic elements to create a magnetic repulsion along a linear bearing interface instead of a rotary bearing interface. Thus, .. the claims below include both rotary configurations and linear configurations where and as appropriate.
ELECTRIC STEPPER MOTOR
[00191] In acccordance with another aspect of the disclosure, an electric stepper motor 10 will now be described.
[00192] For purposes of this aspect of the disclosure, piezoelectric actuators are described as being "electrically connected" to a switching power supply. Such a connection can be made via physical conductors (wires, PCB conductive paths, conductive inks, et cetera) or by any other reasonable means that allows the switching power supply to supply energy to the piezoelectric actuators and causes the piezoelectric effect to change the dimensions of the Date Recue/Date Received 2022-02-28 piezoelectric actuators. This includes, but is not limited to, electromagnetic induction or transfer by capacitance. It is required that the means of electrical connection be able to switch the piezoelectric actuators on and off and/or apply a current flow in one direction and then in the other direction fast enough to allow the motor to operate, as will be made clear in the specification below. This will be referred to generally as "rise" time ¨ the period of time it takes to energize the piezoelectric actuator and/or the capacitator powering it ¨ and the "fall"
time ¨ the period of time it takes to deenergize the piezoelectric actuator and/or the capacitor powering it.
[00193] For purposes of this aspect of the disclosure, motors will generally have a group of components which remains static relative to a load, and a second group of components which will move relative to the first group of components. The first group of components will be referred to collectively as a stator assembly, and the second group referred to collectively as a rotor assembly. Prefixing a component with the word "rotor" or "stator"
indicates which group of components it belongs to in the embodiment/configuration which is currently being described. Piezoelectric actuators in the stator assembly are stator piezoelectric actuators (or simply stator actuators) and magnets affixed to stator piezoelectric actuators are stator magnets, and vice versa with regard to the rotor assembly.
[00194] At the same time, for purposes of this aspect of the disclosure, magnets can also be described as falling into one or both of two distinct types independent of whether they are part of the stator assembly or the rotor assembly. Actuator magnets are magnets which have/are having force imposed upon them by a piezoelectric actuator. Response magnets are magnets which have/are having force imposed upon them via magnetic field interactions with actuator magnets. If only one group of magnets is affixed to piezoelectric actuators, those are the actuator magnets, and the rest of the magnets in the motor are response magnets. If multiple groups of magnets are affixed to piezoelectric actuators, magnets affixed to a piezoelectric actuator which is being energized and causing it to impose force on those magnets are actuator magnets, and magnets which are not so affixed, or which are affixed to a piezoelectric actuator which is not being energized, are response magnets. It is possible for any given magnet to be an actuator magnet or a response magnet or both at any given time depending on the motor controller's configuration and energization of the piezoelectric actuators. A
rotor magnet or a stator magnet may at any time be an actuator magnet, a response magnet, or both.
Date Recue/Date Received 2022-02-28 [00195] By referring to FIGURE 12, the basic nature of this aspect of the disclosure can be easily understood. Outer rotor housing 11 surrounds bearing 12 which is free to rotate on balls 13, which bear the load between the motor and whatever it is mounted in and whatever it is driving. Inner rotor element 14 has multiple rotor magnets 15 having rotor north poles 15a and rotor south poles 15b. Any suitable magnet may be used for rotor magnets 15, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare- earth magnetic particles. Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00196] Stator assembly 19 consists of central hub 18, which supports multiple stator piezoelectric actuators 17. Stator piezoelectric actuators 17 have a magnet mount end 17a and a hub end 17b. Stator piezoelectric actuators 17 are connected to a switching power supply (not shown) which can energize the stator piezoelectric actuators at any reasonable driving frequency. When the stator piezoelectric actuators are energized, they expand, using the principle of piezoelectric expansion, also known as the piezoelectric effect, which is well known to persons of ordinary skill in the art. Stator piezoelectric actuators 17 are constructed so that their expansion is along their long axes: in other words, when the stator piezoelectric actuators are energized, the distance between magnet mount end 17b and hub end 17a increases.
[00197] Mounted to magnet mount ends 17b are stator magnets 16, having stator north poles 16a and stator south poles 16b. Any suitable magnet may be used for stator magnets 16, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare- earth magnetic particles. Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00198] It is strongly preferred that the rotor magnets and the stator magnets have the same poles (north and north or south and south) in opposition at their closest points (as shown) but with proper configuration, it is possible to practice the invention with the rotor magnets and the stator magnets having opposite poles (north and south or south and north) in opposition.
Date Recue/Date Received 2022-02-28 If opposite poles are put into opposition, the motor may require an external initiating force and/or the stator piezoelectric actuators may be required to be energized in a staggered sequence. If reversible electromagnets are used for either the rotor magnets, the stator magnets, or both, the question of initial polarities is unimportant.
[00199] The preferred embodiment pictured in FIGURE 12 shows the invention ready to be practiced. The magnetic forces from the rotor magnets and the stator magnets are at a point of equilibrium where the magnets are in the lowest possible potential energy state with regard to the magnetic repulsion between the rotor magnets and the stator magnets. Inner rotor element 14 will, absent the addition of energy from some exterior source, remain at this point of equilibrium indefinitely.
[00200] To practice the invention, stator piezoelectric actuators 17 are energized. This causes the distance between hub end 17b and magnet mount end 17a to increase, pushing stator magnet 16 closer to rotor magnet 15. This increases the magnetic repulsion between the rotor magnet and the stator magnet, disturbing the equilibrium between them. In the configuration shown, it may be necessary to impart a slight initial rotational force and/or to energize the stator piezoelectric actuators in sequence so as to asymmetrically disturb the equilibrium of magnetic forces and allow rotation to begin.
[00201] Once the equilibrium between the rotor magnets and the stator magnets is disturbed, the system will have more magnetic potential energy than before, which will cause the rotor magnets to exert a force on inner rotor 14. Inner rotor element 14 is free to rotate, so it will rotate in one direction or the other as impelled by the balance of forces. As will be shown in later figures, control of the shape and orientation of the rotor magnets and/or stator magnets will allow for a preferred direction of rotation.
[00202] The switching power supply is controlled by a frequency controller (not shown) which causes it to energize and de-energize stator piezoelectric actuators 17 at a frequency which will continue to convert magnetic potential energy into rotational energy and accelerate inner rotor element 14 in a rotational fashion. It is preferred, but not required, that sensors (not shown) be operably connected to the inner rotor element or otherwise be able to detect its angular velocity, and communicate it to the frequency controller such that the frequency controller can adjust the driving frequency to increase or decrease the force exerted by the Date Recue/Date Received 2022-02-28 stator magnets on the rotor magnets and thus either increase the speed of rotation (under constant load,) increase the applied torque (under increasing load,) or both.
[00203] If such sensors are used, the utility of the invention as a precise stepper motor is further increased. It is preferred, but not required, that a sensor allowing absolute rotational position data also be incorporated into the invention if such a usage is desired. This allows the frequency controller to know where the inner rotor element is at the beginning and the end of a step cycle.
[00204]
With or without the sensors, the switching power supply energizes and de-energizes the stator piezoelectric actuators, with each energization/de-energization cycle imparting a fixed amount of energy into the rotation of the motor. Since the geometry of the stator magnets and the rotor magnets is known, in its simplest embodiment, the invention can be practiced as a stepper motor simply by sending a single energization/de-energization pulse to the stator piezoelectric actuators. This will cause the motor assembly to rotate through the arc-section occupied by a single set of opposing rotor/stator magnets. Once the stator piezoelectric actuators are de-energized, magnetic repulsion between the rotor magnets and the stator magnets will cause the rotation of the rotor to stop as the rotor magnets will not want to move "past" the stator magnets absent the impulse provided by the stator piezoelectric actuators. To get additional fractional rotations, additional energization/de-energization pulses can be sent, which will each produce an additional single rotation through such arc-section.
[00205] If the rotor and the external load on the rotor have too much inertia for the rotor and stator magnets to stop the rotor after the energization/de- energization cycles stop by simple magnetic repulsion, multiple methods of further precisely controlling the rotation of the electric stepper motor may be applied, including but not limited to:
1) It is preferred to use the stator piezoelectric actuators to apply a braking force to the rotor. The frequency controller can be used to cause the stator piezoelectric actuators to push the stator magnets toward the rotor magnets at the point in their rotation where it would tend to slow the rotation of the rotor, not accelerate it. As modern frequency controllers and switching power supplies are capable of very fast and very precise control of electrical circuits, this can provide very precise control of the acceleration/braking of the electric stepper motor.
Date Recue/Date Received 2022-02-28 2) An external brake (not shown) of some kind can be engaged whenever the stepper motor is not desired to be moving, such that as soon as the stator piezoelectric actuators are not being energized, sufficient friction to stop the rotation of the rotor (and the external load) is applied.
[00206] Although the preferred embodiment is described as an electric stepper motor, which is designed to convert electrical potential from a switching power supply into rotational energy, it will be apparent to persons of ordinary skill in the art that since the piezoelectric effect works both ways ¨ electrical potential can be turned into mechanical force, and mechanical force can be turned into electrical potential ¨ that the preferred embodiment can also serve as a generator of electrical power if an external load forces the inner rotor element to rotate against the magnetic force attempting to hold it in equilibrium.
[00207]
Similarly, the preferred embodiment can also be used as a drive motor which also provides regenerative braking by switching from power in (during drive mode) to power out (during regenerative braking mode.) All of the alternate configurations/embodiments/methods of practice described in this paragraph are applicable to all of the embodiments of the invention disclosed in this application.
[00208]
Additional embodiments of the electric stepper motor will now be described.
All of the additional embodiments are alternate configurations of the physical motor itself: the principles by which each embodiment can be used as an electric stepper motor is identical to that described above.
[00209]
FIGURE 13 shows a first alternate embodiment of the electric stepper motor.
The first alternate embodiment of the electric stepper motor works in the same general fashion as the embodiment of FIGURE 12, except where noted otherwise. It likewise would incorporate a switching power supply, frequency controller, and could incorporate sensors, et cetera.
[00210]
Electric stepper motor 20 incorporates rotor piezoelectric actuators 27b, analogous to stator piezoelectric actuators 17 in FIGURE 12. Electric stepper motor 20 also incorporates stator piezoelectric actuators 27a. It is neither preferred nor required for either configuration to be applied with a single (inner and outer) group of piezoelectric actuators or a Date Recue/Date Received 2022-02-28 double (inner and outer) group of piezoelectric actuators: the two configurations are shown for clarity of disclosure.
[00211] When either stator piezoelectric actuators 27a or rotor piezoelectric actuators 27b are energized, rotor magnets 25 are pushed toward stator magnets 26, and as in FIGURE
.. 12, magnetic repulsion is increased, incurring a force against the rotor piezoelectric actuators.
As the rotor piezoelectric actuators are affixed to outer casing 21, which is free to rotate relative to hub 29 on bearing 52 (not identified, see FIGURE 16) which includes race 22 containing balls 23, balls 23 bearing the load and allowing rotation of rotary center bearing element 24 relative to fixed center bearing element 28.
[00212] Depending on the desired method of operation, the stator piezoelectric actuators can be activated in concert with the rotor piezoelectric actuators, or only one or the other group of piezoelectric actuators can be active at any given time. Activating both at once can be used to increase torque/rotational velocity, whereas activating only one or the other can be used for lower output modes. Alternatively, one group of piezoelectric actuators can be wired to deliver input power (motor driving) and the other group wired to receive output power (generation/regenerative braking.) The groups of piezoelectric actuators can also be wired such that some of the actuators in each group are preferentially used to deliver input power and some are preferentially used to receive output power. Finally, all or fewer than all of the piezoelectric actuators in a particular group can be active at any given time to deliver any particular desired amount of input power or receive any particular desired amount of output power, allowing an additional means of controlling power flow and/or reducing electrical fatigue on the individual components as they are cycled in and out of service.
[00213] FIGURE 14 shows the first alternate embodiment in cutaway form.
Electric stepper motor 20, having the same components as in FIGURE 13, is surrounded by backing plate 33 and housing 31, while hollow shaft 32, which is operably affixed to hub 29 (see FIGURE 13) and/or rotary center bearing element 24, allows either delivery of mechanical rotational energy (motor mode) or input of mechanical rotational energy (generation/regenerative braking mode.) [00214] FIGURE 15 shows a pair of opposing piezoelectric actuators and their corresponding magnets in detail. Stator piezoelectric actuator 27b is affixed to stator magnet Date Recue/Date Received 2022-02-28 25 which has stator north pole 25a and stator south pole 25b. Rotor piezoelectric actuator 27a is affixed to rotor magnet 26 which has rotor north pole 26a and rotor south pole 27a. It is preferred, but not required, that the rotor magnets and the stator magnets be asymmetrical to each other (that is, the rotor magnets are not symmetrical with the stator magnets, shown here as their being different sizes) to make it easier to overcome the tendency of the system to "lock"
into a position of minimized magnetic potential energy. Since the magnets are not symmetrical, when they are moved in relation to each other the corresponding magnetic fields will tend to push more in one direction than the other, overcoming such locking symmetry.
However, if it is desired to mainly use pure magnetic repulsion as a braking force for steps of the stepper motor, it may be preferred to make the magnets as symmetrical as possible so as to maximize the efficiency of the individual attraction/repulsion of the individual rotor magnet/stator magnet pairs.
[00215] FIGURE 16 shows a more complete assembly of the first alternate embodiment of the invention for clarity of disclosure. Axial bolt 51 holds the assembly together and keeps the rotary elements on-center. Bearing 52 incorporates rotary center bearing element 24, race 22, balls 23, and fixed center bearing element 28. (See FIGURE 13 for more detail.) [00216] FIGURE 17 shows a second alternate embodiment of the electric stepper motor with a more complex configuration of rotor magnets and stator magnets. This configuration, while not required, is somewhat preferred as it provides multiple benefits to the practice of the invention at the price of higher complexity and cost of manufacture.
[00217] Electric stepper motor 60 comprises rotor assembly 614 and stator assembly 618. Rotably affixing the rotor assembly to the stator assembly is bearing 652 which rotates around central point 611. Mechanically affixed to bearing 652 are one or more stator piezoelectric elements. Shown is a configuration with six such stator piezoelectric elements including stator piezoelectric element 619. Mechanically affixed to the stator piezoelectric elements are stator magnet elements such as stator magnet element 640. The stator magnet elements comprise one or more magnets having a north pole and a south pole, such as stator magnet 617 having stator magnet north pole 617a and stator magnet south pole 617b. There is a gap between the stator magnet elements and one or more rotor magnet elements. Shown is a configuration with six such rotor magnet elements including rotor magnet element 642. Each Date Recue/Date Received 2022-02-28 rotor magnet element includes one or more rotor magnets such as rotor magnet 616, which has rotor magnet north pole 616a and rotor magnet south pole 616b.
[00218] To practice this aspect of the invention, as with prior described embodiments, one or more of the stator piezoelectric actuators, such as stator piezoelectric actuator 619, is energized by a switching power supply (NOT SHOWN) controlled by a frequency controller (NOT SHOWN) such that when, for example, stator piezoelectric actuator 619 is energized, it expands along axis of expansion 619a, causing the corresponding stator magnet element to get closer to one or more rotor magnet elements. This produces a change in the orientation of the magnetic fields of the stator and rotor magnetic elements, causing the corresponding stator magnetic element to exert a force on the rotor magnetic element which in turn causes the rotor magnet element to exert a force on the housing 612, causing it, along with the entire rotor assembly 614 to rotate around central point 611 on bearing 652 relative to stator assembly 618.
This rotational force is transmitted to an external load via hollow shaft 632 (NOT SHOWN, see FIGURE 18.) [00219] It is not required that each rotor magnet element be exactly geometrically opposed to a stator magnet element at any particular time during operation or non-operation and in fact it is likely that the equilibrium during non-operation will result in some degree of offset. It is strongly preferred that there be a rotor magnet element for each stator magnet element, and vice versa. It is required that there be a gap between the rotor magnet elements and the stator magnet elements sufficient to allow the rotor magnet elements to move freely without contacting the stator magnet elements under any reasonable amount of bearing load, rotary speed, or transient vibratory load.
[00220] Although the configuration of magnets shown will be inherently stable due to magnetic attraction between the individual magnets, it is preferred that the magnets in each rotor magnet element and stator magnet element be epoxied or otherwise physically affixed to each other to maintain the desired alignment and prevent shifting under load or due to vibration or other transient phenomena.
[00221] It is strongly preferred, but not required, to use an overlapping configuration of magnets as shown in the rotor magnet elements and the stator magnet elements as this will minimize asymmetries in the overall magnetic field structure in the brushless magnetic motor.
Date Recue/Date Received 2022-02-28 [00222] FIGURE 18 shows a more complete assembly of the second alternate embodiment of the invention for clarity of disclosure along with the addition of an optional set of stator piezoelectric actuators as in FIGURE 13. (See FIGURE 17 for more detail.) Axial bolt 651 holds the assembly together and keeps the elements on-center. Capacitor array bolts 680 affix capacitor array 656 to base element 682 by means of threaded receivers 681. Although shown as traditional capacitive plates, any desired means of capacitive induction of current, such as vacuum-tube capacitors, can be used.
[00223] For purposes of this description, it is assumed that base element 682 is secured to something which is designated as static and therefore base element 682 forms part of a stator assembly. For example, if motor 60 were to be used to drive a turntable, base element 682 would ultimately be statically affixed to the base assembly of the turntable, whereas housing 612 would ultimately be statically affixed to the turntable itself.
[00224] Capacitor array 680, which does not rotate relative to the stator assembly, includes capacitor plates such as capacitor plate 658, each capacitor plate separated by a gap such as capacitor gaps 657a and 657b. Capacitor array energizes rotor piezoelectric array 621, which includes one or more rotor piezoelectric actuators such as rotor piezoelectric actuator 621. The rotor piezoelectric actuators are mechanically affixed to one or more (optional) rotor magnet brackets 678, each rotor magnet bracket having a rotor circumferential surface 662, and (optional) rotor vertical guides 661a and 661b, with all of the rotor magnet brackets forming rotor magnet bracket assembly 660. Mechanically affixed to the rotor piezoelectric actuators, either directly or via the (optional) rotor magnet brackets, are one or more rotor magnet elements such as rotor magnet element 642, each rotor magnet element comprising one or more rotor magnets such as rotor magnet 616, with all of the rotor magnet elements forming rotor magnet assembly 672.
[00225] When energized, the rotor piezoelectric actuators expand toward the center of motor 60 (since they cannot expand against the fixed position of the rest of the rotor assembly including ultimately housing 612) pushing the rotor magnet elements toward the stator magnet elements (see below) and imparting a magnetic force as explained in previous descriptions (see FIGURES 12, 13, and 17.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632.
The rotor piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired Date Recue/Date Received 2022-02-28 and appropriate for the load and conditions. The rotor piezoelectric actuators can be energized without energizing the stator piezoelectric actuators (see below) or in concert with them.
[00226] Rotor magnet assembly 672 radially surrounds stator magnet assembly 670, the rotor magnet assembly separated from the stator magnet assembly by a gap (NOT
SHOWN, see FIGURE 20.) Stator magnet assembly 670 comprises one or more stator magnet elements such as stator magnet element 640, each stator magnet element comprising one or more stator magnets such as stator magnet 617. Stator magnet elements are mechanically affixed to stator piezoelectric assembly 669, which includes one or more stator piezoelectric actuators such as stator piezoelectric actuator 619, either directly or by means of (optional) stator magnet bracket assembly 655. (Optional) stator magnet bracket assembly 655 comprises one or more stator magnet brackets such as stator magnet bracket 676, each stator magnet bracket including a stator circumferential surface such as stator circumferential surface 654 and (optional) stator vertical guides 653a and 653b.
[00227] When energized, the stator piezoelectric actuators expand toward the outer circumference of motor 60 (since they cannot expand toward the fixed position of the rest of the stator assembly) pushing the stator magnet elements toward the rotor magnet elements and imparting a magnetic force as explained in previous descriptions (see FIGURES
12, 13, and 17.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632. The stator piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The stator piezoelectric actuators can be energized without energizing the rotor piezoelectric actuators or in concert with them.
[00228] FIGURE 19 shows the configuration of FIGURE 18 in an alternate phase of assembly for clarity of disclosure. Housing 612 is ready to be placed over the rest of the motor assembly, with capacitor array 656 ready to be secured to base element 682 with capacitor array bolts 680. The rotor and stator elements are assembled, for example rotor piezoelectric actuator affixed to rotor circumferential surface 662 and stator piezoelectric actuator affixed to stator circumferential surface 654, and both ready to be inserted into their respective assemblies.
Date Recue/Date Received 2022-02-28 [00229] FIGURE 20 shows the configuration of FIGURE 18 in a cutaway view for clarity of disclosure. Housing 612 is axially secured by axial bolt 651 but is free to rotate relative to base element 682 as they are mechanically connected only by bearings 652 and 683.
Rotor magnet element 642 is separated from stator magnet element 640 by gap 690. The size of gap 690 can be changed by energizing stator piezoelectric actuator 619 and/or rotor piezoelectric actuator 621. As the piezoelectric actuators change the size of gap 690, the relative orientation of the magnetic fields of the rotor magnet elements and the stator magnet elements will change. This will cause magnetic force to be exerted between magnet elements, but as only the rotor magnet elements (ultimately connected to housing 612) can move, the .. force will cause housing 612 to move, allowing rotary motion to be imparted to hollow shaft 632 and thus to an axle, a wheel, or any other rotary member or rotary load desired.
[00230] FIGURE 21 shows a third alternate embodiment of the invention.
In this embodiment, rather than a plurality of distinctive magnets, the rotor magnets comprise a single piece of rotor magnetic material, which is structured to have a plurality of magnetic regions, each magnetic region having a north pole and a south pole. Similarly, there are two individual pieces of stator magnetic material having a plurality of magnetic regions.
Each piece of stator magnetic material is attached to one end of a single piezoelectric actuator.
As shown, the rotational precision of the electric stepper motor would not be high, and it would not be possible to make this embodiment as precise as the previously described embodiments due to the inherent properties of the type of magnetic material used. It is preferred to use this embodiment of the invention in applications where fine control is less important than simplicity and lower cost.
[00231] Electric stepper motor 80 comprises rotor assembly 82, stator magnet assemblies 84 and 87, and piezoelectric actuator 810 which is operably affixed to PCB 92 (NOT SHOWN: See FIGURE 22.) Rotor assembly 82, which is free to rotate relative to all stator assembly components and is attached to whatever rotational load (NOT
SHOWN) it is desired to accelerate with the motor, is comprised of magnetic material (or can have an inner section of magnetic material surrounded by non-magnetic material as desired) which has magnetic regions, each magnetic region having a north pole and a south pole such as rotor north poles 82a and 82b and rotor south poles 83a and 83b. Opposite the rotor assembly's magnetic material, separated by a gap (See FIGURE 22,) are stator magnet assemblies 84 and 87. It is possible to construct this embodiment of the invention with a single stator magnet Date Recue/Date Received 2022-02-28 assembly, but it is strongly preferred to use two symmetrical stator magnet assemblies as shown for purposes of balance and to maximize the piezoelectric actuator's efficiency.
[00232] First stator magnet assembly 84, similarly to rotor section 82, is composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and rotor south poles 86a and 86b. Second stator magnet assembly 87, is likewise composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and stator south poles 86a and 86b.
[00233] FIGURE 22 shows a cutaway view of the third alternate embodiment of the invention for additional clarity of disclosure. Electric stepper motor 80 has gap 91, which separates the various motor assemblies (see FIGURE 21) and allows the motor to also serve as a no-contact magnetic bearing so long as the planar load does not materially affect the gap as maintained by the magnetic fields of the rotor magnet assembly and the stator magnet assemblies. This is an additional advantage of several of the embodiments and configurations of the invention disclosed herein. PCB 92 is a printed circuit board which is both mechanically and electrically affixed to piezoelectric actuator 810 and provides it with electrical potential from a switching power supply (NOT SHOWN.) [00234] To practice this aspect of the invention, an electrical potential is put across piezoelectric actuator 810, which is electrically connected to PCB 92. This causes piezoelectric actuator 810 to expand along its long axis, changing the relative position of the stator magnet assemblies and the rotor assembly.
[00235] This in turn causes electromagnetic force to be exerted on the rotor assembly, which will rotate to a position which will minimize the magnetic potential energy between the rotor assembly and the stator assemblies. The electrical potential across piezoelectric actuator 810, is then removed and/or reversed, causing it to contract along its long axis, again changing the relative position of the various magnet assemblies, and imparting more rotational energy to the rotor assembly. A switching power supply (NOT SHOWN) continuously cycles the electrical potential across the piezoelectric actuator to produce the desired rotational energy as in earlier described embodiments.
Date Recue/Date Received 2022-02-28 [00236] It is optional, but neither preferred nor required, for either the rotor assembly or the stator assembly, or both, to comprise multiple magnets as in earlier described configurations. (See FIGURE 12, FIGURE 13, and/or FIGURE 17.) So long as the rotor assembly and the stator assembly are configured as shown, the configuration of this third alternate embodiment incorporating a single piezoelectric actuator will function and provide the benefits of the invention.
[00237] Alternate configurations of this aspect the invention, which can be applied to any of the described embodiments, will now be disclosed.
[00238] In a first alternate configuration of this aspect (NOT SHOWN) some or all of .. the rotor magnets, or some or all of the stator magnets, of either the preferred embodiment or the first alternate embodiment are replaced with electromagnets.
[00239] In a second alternate configuration of this aspect (NOT SHOWN) one or more elastic members is fitted into the motor assembly such that the piezoelectric actuators are working against the elastic members when they are energized, compressing them and creating .. elastic potential energy, so that when the piezoelectric actuator(s) is/are de-energized, the magnet(s) affixed to the piezoelectric actuator(s) return to their prior position more quickly and without the need to impose a reverse polarity potential across the piezoelectric actuator when the elastic potential energy provides impetus to the piezoelectric actuators.
[00240] In a third alternate configuration of this aspect (NOT SHOWN) the features of the first and second configurations are combined.
[00241] In many of the described embodiments and if necessary, fluid can be forcibly circulated around the assemblies or even through the gap(s) to cool the motor, but as many piezoelectric devices actually work better when they reach a relatively high operating temperature, the need for cooling will be minimal in many applications. This is another advantage of the invention. It is required that for all embodiments and configurations of the invention, that operating temperatures be kept low enough to avoid demagnetization of any permanent magnets which are used. This will vary as various kinds of magnetic material have different demagnetization thresholds. (For example, some ferrite magnets can tolerate temperatures up to 250 C, whereas some rare-earth magnets can only tolerate temperatures up .. to 100 C.) Date Recue/Date Received 2022-02-28 [00242] It will be apparent to those of ordinary skill in the art that while this aspect of the invention and its preferred embodiments are described in terms of rotary motors, the principles taught by the invention can be used to create linear motors, such as reciprocating motors, by using the basic principle of piezoelectric motivation of opposing magnetic elements to create a linear force instead of a centripetal force. Thus, the claims below include both rotary configurations and linear configurations where and as appropriate.
ELECTRIC MOTOR WITH POSITIONAL SENSING
[00243] In acccordance with another aspect of the disclosure, an electric motor with positional sensing 10 will now be described.
[00244] For purposes of this aspect, piezoelectric actuators are described as being "electrically connected" to a power supply. Such a connection can be made via physical conductors (wires, PCB conductive paths, conductive inks, etcetera) or by any other reasonable means that allows the power supply to supply energy to the piezoelectric actuators and causes the piezoelectric effect to change the dimensions of the piezoelectric actuators. This includes, but is not limited to, electromagnetic induction or transfer by capacitance.
It is required that the means of electrical connection be able to switch the piezoelectric actuators on and off and/or apply a current flow in one direction and then in the other direction fast enough to allow the motor to operate, as will be made clear in the specification below. This will be referred to generally as "rise" time ¨ the period of time it takes to energize the piezoelectric actuator and/or the capacitator powering it ¨ and the "fall" time ¨ the period of time it takes to deenergize the piezoelectric actuator and/or the capacitor powering it.
[00245] For purposes of this aspect, motors will generally have a group of components which remains static relative to a load, and a second group of components which will move relative to the first group of components. The first group of components will be referred to collectively as a stator assembly, and the second group referred to collectively as a rotor assembly. Prefixing a component with the word "rotor" or "stator" indicates which group of components it belongs to in the embodiment/configuration which is currently being described.
Piezoelectric actuators in the stator assembly are stator piezoelectric actuators (or simply stator actuators) and magnets affixed to stator piezoelectric actuators are stator magnets, and vice versa with regard to the rotor assembly. At the same time, for purposes of this aspect, magnets Date Recue/Date Received 2022-02-28 can also be described as falling into one or both of two distinct types independent of whether they are part of the stator assembly or the rotor assembly. Actuator magnets are magnets which have/are having force imposed upon them by a piezoelectric actuator. Response magnets are magnets which have/are having force imposed upon them via magnetic field interactions with actuator magnets. If only one group of magnets is affixed to piezoelectric actuators, those are the actuator magnets, and the rest of the magnets in the motor are response magnets. If multiple groups of magnets are affixed to piezoelectric actuators, magnets affixed to a piezoelectric actuator which is being energized and causing it to impose force on those magnets are actuator magnets, and magnets which are not so affixed, or which are affixed to a piezoelectric actuator which is not being energized, are response magnets. It is possible for any given magnet to be an actuator magnet or a response magnet or both at any given time depending on the motor controller's configuration and energization of the piezoelectric actuators. A
rotor magnet or a stator magnet may at any time be an actuator magnet, a response magnet, or both.
[00246] By referring to FIGURE 23, the basic nature of the electric motor with positional sensing 10 can be easily understood. Outer rotor housing 11 surrounds bearing 12 which is free to rotate on balls 13, which bear the load between the motor and whatever it is mounted in and whatever it is driving. Inner rotor element 14 has multiple rotor magnets 15 having rotor north poles 15a and rotor south poles 15b. Any suitable magnet may be used for rotor magnets 15, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare-earth magnetic particles.
Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00247] Stator assembly 19 consists of central hub 18, which supports multiple stator piezoelectric actuators 17. Stator piezoelectric actuators 17 have a magnet mount end 17a and a hub end 17b. Stator piezoelectric actuators 17 are connected to a switching power supply (not shown) which can energize the stator piezoelectric actuators at any reasonable driving frequency. When the stator piezoelectric actuators are energized, they expand, using the principle of piezoelectric expansion, also known as the piezoelectric effect, which is well known to persons of ordinary skill in the art. Stator piezoelectric actuators 17 are constructed so that their expansion is along their long axes: in other words, when the stator piezoelectric Date Recue/Date Received 2022-02-28 actuators are energized, the distance between magnet mount end 17b and hub end 17a increases.
[00248] Mounted to magnet mount ends 17b are stator magnets 16, having stator north poles 16a and stator south poles 16b. Any suitable magnet may be used for stator magnets 16, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare- earth magnetic particles. Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00249] It is strongly preferred that the rotor magnets and the stator magnets have the same poles (north and north or south and south) in opposition at their closest points (as shown) but with proper configuration, it is possible to practice the invention with the rotor magnets and the stator magnets having opposite poles (north and south or south and north) in opposition.
If opposite poles are put into opposition, the motor may require an external initiating force and/or the stator piezoelectric actuators may be required to be energized in a staggered sequence. If reversible electromagnets are used for either the rotor magnets, the stator magnets, or both, the question of initial polarities is unimportant.
[00250] The preferred embodiment pictured in FIGURE 23 shows the invention ready to be practiced. The magnetic forces from the rotor magnets and the stator magnets are at a point of equilibrium where the magnets are in the lowest possible potential energy state with regard to the magnetic repulsion between the rotor magnets and the stator magnets. Inner rotor element 14 will, absent the addition of energy from some exterior source, remain at this point of equilibrium indefinitely.
[00251] To practice the invention, stator piezoelectric actuators 17 are energized. This causes the distance between hub end 17b and magnet mount end 17a to increase, pushing stator magnet 16 closer to rotor magnet 15. This increases the magnetic repulsion between the rotor magnet and the stator magnet, disturbing the equilibrium between them. In the configuration shown, it may be necessary to impart a slight initial rotational force and/or to energize the stator piezoelectric actuators in sequence so as to asymmetrically disturb the equilibrium of magnetic forces and allow rotation to begin.
Date Recue/Date Received 2022-02-28 [00252] Once the equilibrium between the rotor magnets and the stator magnets is disturbed, the system will have more magnetic potential energy than before, which will cause the rotor magnets to exert a force on inner rotor 14. Inner rotor element 14 is free to rotate, so it will rotate in one direction or the other as impelled by the balance of forces. As will be shown in later figures, control of the shape and orientation of the rotor magnets and/or stator magnets will allow for a preferred direction of rotation.
[00253] The switching power supply is controlled by a frequency controller (not shown) which causes it to energize and de-energize stator piezoelectric actuators 17 at a frequency which will continue to convert magnetic potential energy into rotational energy and accelerate inner rotor element 14 in a rotational fashion. It is preferred, but not required, that sensors (not shown) be operably connected to the inner rotor element or otherwise be able to detect its angular velocity, and communicate it to the frequency controller such that the frequency controller can adjust the driving frequency to increase or decrease the force exerted by the stator magnets on the rotor magnets and thus either increase the speed of rotation (under constant load,) increase the applied torque (under increasing load,) or both.
[00254] To obtain the benefits of the positional sensing aspect of the invention, the frequency controller is connected to, or integrated with, a counting device, an induced current sensor, or both.
[00255] If a counting device is used, the frequency controller is connected to or integrated with the counting device (not shown,) which can detect each instance of a current being induced by the rotor magnets rotating past the stator magnets. The counting device could be as simple as a circuit in the frequency controller which can detect back-currents or it can be a more sophisticated separate device as is appropriate to the application in which the electric motor with positional sensing is being used.
[00256] Because the geometry of the rotor magnets and the stator magnets is known, the amount of rotational arc the motor, or any element attached to it, goes through each time the rotor magnets rotate past the stator magnets is also known. For instance, if the rotor magnet/stator magnet pairs each encompass an arc of 10 degrees (or it /18 radians) of the rotation of the motor, each instance of a current induction equals a rotation of 10 degrees (or it /18 radians). To obtain distance moved, the diameter of the circle described by the element Date Recue/Date Received 2022-02-28 whose position is to be measured is multiplied times the number of current inductions and hence the number of fractional rotations. In a device with a positional element located one meter from the center of the rotor, each current induction / movement of the rotor and stator magnets would equate to an angular movement of:
[00257] 2 * n * 1 meter * 10 degrees / 360 degrees = it /16 meters (or ¨19.6cm) (Where 2 * n * r is the formula for the circumference of a circle with [00258] radius r and the circle here has a radius of one meter.) [00259] It is trivial to derive the angular velocity of the positional element once its angular motion is known: the amount of distance traveled in the prior step is simply divided by the time it took for the element to move that distance. If it took 0.1 seconds for the positional element in the prior example to move through an arc of 10 degrees (or it /18 radians) and thus move it /16 meters then the angular velocity would be:
[00260] it /16 meters / 0.1 seconds = it /1.6 meters/second (or ¨1.96 m/s) [00261] It is required that the counting device be able to keep track of the motion of the motor whether or not the piezoelectric actuators are being energized by the switching power supply in some fashion. It is strongly preferred, but not required, that the counting device be able to separately keep track of both the currents which are induced into the motor by the switching power supply (for causing the actuators to move the stator magnets and thus turn the rotor assembly) and currents which are induced into the motor by countermotion of the load or .. other elements attached to the rotor assembly which cause it to rotate by the imposition of an external torque. It is optional, but neither preferred nor required, for the frequency counter to interact with the counting device in such a way as to calibrate the number of current inductions the frequency controller has initiated with the number the counting device detects so that the counting device has a redundant source of information it can use to ensure that current inductions are being counted correctly.
[00262] If an induced current sensor is used, the frequency controller is connected to or integrated with the counting device (not shown,) which can dynamically detect the induced current of a current being induced by the rotor magnets rotating past the stator magnets. The induced current sensor can be as simple as a circuit in the frequency controller which can detect Date Recue/Date Received 2022-02-28 back- currents or it can be a more sophisticated separate device as is appropriate to the application in which the electric motor with positional sensing is being used.
[00263] To use the induced current sensor, the electric motor with positional sensing is operably connected to another motor or other device (hereafter the "calibration load") which can rotate the electric motor with positional sensing without having to apply power to the piezoelectric actuators. It is strongly preferred to use the calibration load to rotate the rotor assembly, but depending on the needs of the particular application, it is optional to use the calibration load to rotate the stator assembly. Whichever of the rotor/stator assemblies is being rotated, it is required that the other either be held static or that its motion be somehow separately measured to allow for full calibration. The former is strongly preferred.
[00264] Once the calibration load is connected (for illustration the following will assume that the stator assembly and the rest of the motor as a whole is being held static and the rotor assembly is being rotated by the calibration load) it is used to accelerate the rotor assembly at a known rate until it is spinning at a known and fixed angular velocity. On a first calibration pass, the induced current sensor is used to dynamically track the current induced in the electric motor with positional sensing by the motion of the rotor magnets past the stator magnets. It is strongly preferred that the motor be rotated for several revolutions to obtain a good set of average values. Because no two of the rotor magnets and/or stator magnets will have exactly the same magnetic strength (this can be varied by design or the inevitable inconsistencies in manufacture can be used) the induced current sensor will track the current being induced as a variable periodic wave (the "base wave.") [00265] As the base wave will be unique, at sufficient precision of measurement, at each point in the rotation of the rotor assembly to any reasonable level, it can be used to map the magnetic field of the rotor magnets relative to the stator magnets. This data is stored for a later step in the process.
[00266] It is optional but strongly preferred to then repeat the calibration steps above with the piezoelectric actuators energized by the stepping power supply, creating measurements of another variable periodic wave, the "energized" wave. This can be done at any reasonable level of energization, but it is required that the calibration load have sufficient power to rotate the motor against the resulting (potentially) increased magnetic Date Recue/Date Received 2022-02-28 attraction/repulsion, especially if the motor starts out from a dead stop. As will be apparent to persons of ordinary skill in the art, the "back-current" which will be measured if the piezoelectric actuators are energized by the power supply will be the sum of the current being induced by the power supply and the current being induced by the calibration load, which will not be in phase, and the measurements must be used accordingly when using the energized wave in later steps.
[00267] It is optional to first spin up the motor with the frequency controller and then apply the calibration load with (and against) up to full energization of the piezoelectric actuators. This will create yet another variable periodic wave or waves (the base wave and all of the energized waves collectively the "waves.") All of the waves should be quite similar to the base wave when adjusted for the current being supplied by the power supply, but will contain additional minute variations. This data is also stored for a later step in the process. It is optional, but not preferred, to use multiple levels of energization, or even to only used an energized level and not measure the base wave.
[00268] Once the waves are measured and the data stored, it is used to construct a map of the magnetic fields of the rotor and stator magnets (the "field map.") To practice the invention using the induced current sensor, the motor is put into operation, and the point on the map of the magnetic fields where the rotor assembly is located is determined at a time or times when the position of the rotor is to be determined. This is known as "resolving" the motor or .. resolving the rotor position.
[00269] It is optional, but strongly preferred, to use some exterior sensor to measure any material external electromagnetic fields, variations in temperature, et cetera, which might affect the nature of the waves when using the positional sensing capability of the motor. While the relative positions of the rotor magnets and stator magnets should produce consistently shaped waves, the actual amplitude and frequency of the waves, and thus the precision of the positional sensing, will vary according to these and other factors which will be apparent to those of ordinary skill in the art.
[00270] Although the preferred embodiment is described as an electric motor with positional sensing, which is designed to convert electrical potential from a switching power supply into rotational energy, it will be apparent to persons of ordinary skill in the art that since Date Recue/Date Received 2022-02-28 the piezoelectric effect works both ways ¨ electrical potential can be turned into mechanical force, and mechanical force can be turned into electrical potential ¨ that the preferred embodiment can also serve as a generator of electrical power if an external load forces the inner rotor element to rotate against the magnetic force attempting to hold it in equilibrium.
.. Similarly, the preferred embodiment can also be used as a drive motor which also provides regenerative braking by switching from power in (during drive mode) to power out (during regenerative braking mode.) All of the alternate configurations/embodiments/methods of practice described in this paragraph are applicable to all of the embodiments of the invention disclosed in this application.
[00271] Additional embodiments of the electric motor with positional sensing will now be described. All of the additional embodiments are alternate configurations of the physical motor itself: the principles by which each embodiment can be used as an electric motor with positional sensing is identical to that described above.
[00272] FIGURE 24 shows a first alternate embodiment of the electric motor with positional sensing. The first alternate embodiment of the electric motor with positional sensing works in the same general fashion as the embodiment of FIGURE 23, except where noted otherwise. It likewise would incorporate a switching power supply, frequency controller, and could incorporate sensors, et cetera.
[00273] Electric motor with positional sensing 20 incorporates rotor piezoelectric actuators 27b, analogous to stator piezoelectric actuators 17 in FIGURE 23.
[00274] Electric motor with positional sensing 20 also incorporates stator piezoelectric actuators 27a. It is neither preferred nor required for either configuration to be applied with a single (inner and outer) group of piezoelectric actuators or a double (inner and outer) group of piezoelectric actuators: the two configurations are shown for clarity of disclosure.
[00275] When either stator piezoelectric actuators 27a or rotor piezoelectric actuators 27b are energized, rotor magnets 25 are pushed toward stator magnets 26, and as in FIGURE
23, magnetic repulsion is increased, incurring a force against the rotor piezoelectric actuators.
As the rotor piezoelectric actuators are affixed to outer casing 21, which is free to rotate relative to hub 29 on bearing 52 (not identified, see FIGURE 27) which includes race 22 containing Date Recue/Date Received 2022-02-28 balls 23, balls 23 bearing the load and allowing rotation of rotary center bearing element 24 relative to fixed center bearing element 28.
[00276] Depending on the desired method of operation, the stator piezoelectric actuators can be activated in concert with the rotor piezoelectric actuators, or only one or the other group of piezoelectric actuators can be active at any given time. Activating both at once can be used to increase torque/rotational velocity, whereas activating only one or the other can be used for lower output modes. Alternatively, one group of piezoelectric actuators can be wired to deliver input power (motor driving) and the other group wired to receive output power (generation/regenerative braking.) The groups of piezoelectric actuators can also be wired such that some of the actuators in each group are preferentially used to deliver input power and some are preferentially used to receive output power. Finally, all or fewer than all of the piezoelectric actuators in a particular group can be active at any given time to deliver any particular desired amount of input power or receive any particular desired amount of output power, allowing an additional means of controlling power flow and/or reducing electrical fatigue on the individual components as they are cycled in and out of service.
[00277] FIGURE 25 shows the first alternate embodiment in cutaway form.
Electric motor with positional sensing 20, having the same components as in FIGURE 24, is surrounded by backing plate 33 and housing 31, while hollow shaft 32, which is operably affixed to hub 29 (see FIGURE 24) and/or rotary center bearing element 24, allows either delivery of mechanical rotational energy (motor mode) or input of mechanical rotational energy (generation/regenerative braking mode.) [00278] FIGURE 26 shows a pair of opposing piezoelectric actuators and their corresponding magnets in detail. Stator piezoelectric actuator 27b is affixed to stator magnet which has stator north pole 25a and stator south pole 25b. Rotor piezoelectric actuator 27a 25 is affixed to rotor magnet 26 which has rotor north pole 26a and rotor south pole 27a. It is preferred, but not required, that the rotor magnets and the stator magnets be asymmetrical to each other (that is, the rotor magnets are not symmetrical with the stator magnets, shown here as their being different sizes) to make it easier to overcome the tendency of the system to "lock"
into a position of minimized magnetic potential energy. Since the magnets are not symmetrical, when they are moved in relation to each other the corresponding magnetic fields will tend to push more in one direction than the other, overcoming such locking symmetry.
Date Recue/Date Received 2022-02-28 [00279] FIGURE 27 shows a more complete assembly of the first alternate embodiment of the invention for clarity of disclosure. Axial bolt 51 holds the assembly together and keeps the rotary elements on-center. Bearing 52 incorporates rotary center bearing element 24, race 22, balls 23, and fixed center bearing element 28. (See FIGURE 24 for more detail.) [00280] FIGURE 28 shows a second alternate embodiment of the electric motor with positional sensing with a more complex configuration of rotor magnets and stator magnets.
This configuration, while not required, is somewhat preferred as it provides multiple benefits to the practice of the invention at the price of higher complexity and cost of manufacture.
[00281] Electric motor with positional sensing 60 comprises rotor assembly 614 and stator assembly 618. Rotably affixing the rotor assembly to the stator assembly is bearing 652 which rotates around central point 611. Mechanically affixed to bearing 652 are one or more stator piezoelectric elements. Shown is a configuration with six such stator piezoelectric elements including stator piezoelectric element 619. Mechanically affixed to the stator piezoelectric elements are stator magnet elements such as stator magnet element 640. The stator magnet elements comprise one or more magnets having a north pole and a south pole, such as stator magnet 617 having stator magnet north pole 617a and stator magnet south pole 617b.
There is a gap between the stator magnet elements and one or more rotor magnet elements.
Shown is a configuration with six such rotor magnet elements including rotor magnet element 642. Each rotor magnet element includes one or more rotor magnets such as rotor magnet 616, which has rotor magnet north pole 616a and rotor magnet south pole 616b.
[00282] To practice this aspect of the invention, as with prior described embodiments, one or more of the stator piezoelectric actuators, such as stator piezoelectric actuator 619, is energized by a switching power supply (NOT SHOWN) controlled by a frequency controller (NOT SHOWN) such that when, for example, stator piezoelectric actuator 619 is energized, it expands along axis of expansion 619a, causing the corresponding stator magnet element to get closer to one or more rotor magnet elements. This produces a change in the orientation of the magnetic fields of the stator and rotor magnetic elements, causing the corresponding stator magnetic element to exert a force on the rotor magnetic element which in turn causes the rotor magnet element to exert a force on the housing 612, causing it, along with the entire rotor assembly 614 to rotate around central point 611 on bearing 652 relative to stator assembly 618.
Date Recue/Date Received 2022-02-28 This rotational force is transmitted to an external load via hollow shaft 632 (NOT SHOWN, see FIGURE 29.) [00283] It is not required that each rotor magnet element be exactly geometrically opposed to a stator magnet element at any particular time during operation or non-operation and in fact it is likely that the equilibrium during non-operation will result in some degree of offset. It is strongly preferred that there be a rotor magnet element for each stator magnet element, and vice versa. It is required that there be a gap between the rotor magnet elements and the stator magnet elements sufficient to allow the rotor magnet elements to move freely without contacting the stator magnet elements under any reasonable amount of bearing load, rotary speed, or transient vibratory load.
[00284] Although the configuration of magnets shown will be inherently stable due to magnetic attraction between the individual magnets, it is preferred that the magnets in each rotor magnet element and stator magnet element be epoxied or otherwise physically affixed to each other to maintain the desired alignment and prevent shifting under load or due to vibration .. or other transient phenomena.
[00285] It is strongly preferred, but not required, to use an overlapping configuration of magnets as shown in the rotor magnet elements and the stator magnet elements as this will minimize asymmetries in the overall magnetic field structure in the brushless magnetic motor.
FIGURE 7 shows a more complete assembly of the second alternate embodiment of the invention for clarity of disclosure along with the addition of an optional set of stator piezoelectric actuators as in FIGURE 24. (See FIGURE 28 for more detail.) Axial bolt 651 holds the assembly together and keeps the elements on-center. Capacitor array bolts 680 affix capacitor array 656 to base element 682 by means of threaded receivers 681.
Although shown as traditional capacitive plates, any desired means of capacitive induction of current, such as vacuum-tube capacitors, can be used.
[00286] For purposes of this description, it is assumed that base element 682 is secured to something which is designated as static and therefore base element 682 forms part of a stator assembly. For example, if motor 60 were to be used to drive the wheel of an electric vehicle, base element 682 would ultimately be statically affixed to the chassis of the vehicle, whereas housing 612 would ultimately be statically affixed to the wheel of the vehicle.
Date Recue/Date Received 2022-02-28 [00287] Capacitor array 680, which does not rotate relative to the stator assembly, includes capacitor plates such as capacitor plate 658, each capacitor plate separated by a gap such as capacitor gaps 657a and 657b. Capacitor array energizes rotor piezoelectric array 621, which includes one or more rotor piezoelectric actuators such as rotor piezoelectric actuator 621. The rotor piezoelectric actuators are mechanically affixed to one or more (optional) rotor magnet brackets 678, each rotor magnet bracket having a rotor circumferential surface 662, and (optional) rotor vertical guides 661a and 661b, with all of the rotor magnet brackets forming rotor magnet bracket assembly 660. Mechanically affixed to the rotor piezoelectric actuators, either directly or via the (optional) rotor magnet brackets, are one or more rotor magnet elements such as rotor magnet element 642, each rotor magnet element comprising one or more rotor magnets such as rotor magnet 616, with all of the rotor magnet elements forming rotor magnet assembly 672.
[00288] When energized, the rotor piezoelectric actuators expand toward the center of motor 60 (since they cannot expand against the fixed position of the rest of the rotor assembly including ultimately housing 612) pushing the rotor magnet elements toward the stator magnet elements (see below) and imparting a magnetic force as explained in previous descriptions (see FIGURES 23, 24, and 28.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632.
The rotor piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The rotor piezoelectric actuators can be energized without energizing the stator piezoelectric actuators (see below) or in concert with them.
[00289] Rotor magnet assembly 672 radially surrounds stator magnet assembly 670, the rotor magnet assembly separated from the stator magnet assembly by a gap (NOT
SHOWN, see FIGURE 31.) Stator magnet assembly 670 comprises one or more stator magnet elements such as stator magnet element 640, each stator magnet element comprising one or more stator magnets such as stator magnet 617. Stator magnet elements are mechanically affixed to stator piezoelectric assembly 669, which includes one or more stator piezoelectric actuators such as stator piezoelectric actuator 619, either directly or by means of (optional) stator magnet bracket assembly 655. (Optional) stator magnet bracket assembly 655 comprises one or more stator magnet brackets such as stator magnet bracket 676, each stator magnet bracket including a stator circumferential surface such as stator circumferential surface 654 and (optional) stator vertical guides 653a and 653b.
Date Recue/Date Received 2022-02-28 [00290] When energized, the stator piezoelectric actuators expand toward the outer circumference of motor 60 (since they cannot expand toward the fixed position of the rest of the stator assembly) pushing the stator magnet elements toward the rotor magnet elements and imparting a magnetic force as explained in previous descriptions (see FIGURES
23, 24, and 28.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632. The stator piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The stator piezoelectric actuators can be energized without energizing the rotor piezoelectric actuators or in concert with them.
[00291] FIGURE 30 shows the configuration of FIGURE 29 in an alternate phase of assembly for clarity of disclosure. Housing 612 is ready to be placed over the rest of the motor assembly, with capacitor array 656 ready to be secured to base element 682 with capacitor array bolts 680. The rotor and stator elements are assembled, for example rotor piezoelectric actuator affixed to rotor circumferential surface 662 and stator piezoelectric actuator affixed to stator circumferential surface 654, and both ready to be inserted into their respective assemblies.
[00292] FIGURE 31 shows the configuration of FIGURE 29 in a cutaway view for clarity of disclosure. Housing 612 is axially secured by axial bolt 651 but is free to rotate relative to base element 682 as they are mechanically connected only by bearings 652 and 683.
Rotor magnet element 642 is separated from stator magnet element 640 by gap 690. The size of gap 690 can be changed by energizing stator piezoelectric actuator 619 and/or rotor piezoelectric actuator 621. As the piezoelectric actuators change the size of gap 690, the relative orientation of the magnetic fields of the rotor magnet elements and the stator magnet elements will change. This will cause magnetic force to be exerted between magnet elements, .. but as only the rotor magnet elements (ultimately connected to housing 612) can move, the force will cause housing 612 to move, allowing rotary motion to be imparted to hollow shaft 632 and thus to an axle, a wheel, or any other rotary member or rotary load desired.
[00293] FIGURE 32 shows a third alternate embodiment of the invention.
In this embodiment, rather than a plurality of distinctive magnets, the rotor magnets comprise a single piece of rotor magnetic material, which is structured to have a plurality of magnetic regions, each magnetic region having a north pole and a south pole. Similarly, there are two individual Date Recue/Date Received 2022-02-28 pieces of stator magnetic material having a plurality of magnetic regions.
Each piece of stator magnetic material is attached to one end of a single piezoelectric actuator.
[00294] Electric motor with positional sensing 80 comprises rotor assembly 82, stator magnet assemblies 84 and 87, and piezoelectric actuator 810 which is operably affixed to PCB
92 (NOT SHOWN: See FIGURE 33.) Rotor assembly 82, which is free to rotate relative to all stator assembly components and is attached to whatever rotational load (NOT
SHOWN) it is desired to accelerate with the motor, is comprised of magnetic material (or can have an inner section of magnetic material surrounded by non-magnetic material as desired) which has magnetic regions, each magnetic region having a north pole and a south pole such as rotor north poles 82a and 82b and rotor south poles 83a and 83b. Opposite the rotor assembly's magnetic material, separated by a gap (See FIGURE 33,) are stator magnet assemblies 84 and 87. It is possible to construct this embodiment of the invention with a single stator magnet assembly, but it is strongly preferred to use two symmetrical stator magnet assemblies as shown for purposes of balance and to maximize the piezoelectric actuator's efficiency. First stator magnet assembly 84, similarly to rotor section 82, is composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and rotor south poles 86a and 86b. Second stator magnet assembly 87, is likewise composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and stator south poles 86a and 86b.
[00295] FIGURE 33 shows a cutaway view of the third alternate embodiment of this aspect of the disclosure for additional clarity. Electric motor with positional sensing 80 has gap 91, which separates the various motor assemblies (see FIGURE 32) and allows the motor to also serve as a no-contact magnetic bearing so long as the planar load does not materially affect the gap as maintained by the magnetic fields of the rotor magnet assembly and the stator magnet assemblies. This is an additional advantage of several of the embodiments and configurations of the invention disclosed herein. PCB 92 is a printed circuit board which is both mechanically and electrically affixed to piezoelectric actuator 810 and provides it with electrical potential from a switching power supply (NOT SHOWN.) [00296] If necessary, fluid can be forcibly circulated around the assemblies or even through the gap to cool the motor, but as many piezoelectric devices actually work better when Date Recue/Date Received 2022-02-28 they reach a relatively high operating temperature, the need for cooling will be minimal in many applications. This is another advantage of the invention. It is required that for all embodiments and configurations of the invention, that operating temperatures be kept low enough to avoid demagnetization of any permanent magnets which are used. This will vary as various kinds of magnetic material have different demagnetization thresholds.
(For example, some ferrite magnets can tolerate temperatures up to 250 C, whereas some rare-earth magnets can only tolerate temperatures up to 100 C.) [00297] To practice an embodiment of this aspect of the invention, an electrical potential is put across piezoelectric actuator 810, which is electrically connected to PCB 92. This causes piezoelectric actuator 810 to expand along its long axis, changing the relative position of the stator magnet assemblies and the rotor assembly. This in turn causes electromagnetic force to be exerted on the rotor assembly, which will rotate to a position which will minimize the magnetic potential energy between the rotor assembly and the stator assemblies. The electrical potential across piezoelectric actuator 810, is then removed and/or reversed, causing it to contract along its long axis, again changing the relative position of the various magnet assemblies, and imparting more rotational energy to the rotor assembly. A
switching power supply (NOT SHOWN) continuously cycles the electrical potential across the piezoelectric actuator to produce the desired rotational energy as in earlier described embodiments.
[00298] It is optional, but neither preferred nor required, for either the rotor assembly or the stator assembly, or both, to comprise multiple magnets as in earlier described configurations. (See FIGURE 23, FIGURE 24, and/or FIGURE 28.) So long as the rotor assembly and the stator assembly are configured as shown, the configuration of this third alternate embodiment incorporating a single piezoelectric actuator will function and provide the benefits of the invention.
[00299] Alternate configurations of this aspect of the disclosure, which can be applied to any of the described embodiments, will now be disclosed.
[00300] In a first alternate configuration of this aspect (NOT SHOWN) some or all of the rotor magnets, or some or all of the stator magnets, of either the preferred embodiment or the first alternate embodiment are replaced with electromagnets.
Date Recue/Date Received 2022-02-28 [00301] In a second alternate configuration of this aspect (NOT SHOWN) one or more elastic members is fitted into the motor assembly such that the piezoelectric actuators are working against the elastic members when they are energized, compressing them and creating elastic potential energy, so that when the piezoelectric actuator(s) is/are de-energized, the magnet(s) affixed to the piezoelectric actuator(s) return to their prior position more quickly and without the need to impose a reverse polarity potential across the piezoelectric actuator when the elastic potential energy provides impetus to the piezoelectric actuators.
[00302] In a third alternate configuration of this aspect (NOT SHOWN) the features of the first and second configurations are combined.
[00303] It will be apparent to those of ordinary skill in the art that while this aspect and its preferred embodiments are described in terms of rotary motors, the principles taught by the invention can be used to create linear motors, such as reciprocating motors, by using the basic principle of piezoelectric motivation of opposing magnetic elements to create a linear force instead of a centripetal force. Thus, the claims below include both rotary configurations and linear configurations where and as appropriate.
[00304] While various embodiments and configurations of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above exemplary embodiments.
[00305] This application ¨ taken as a whole with the abstract, specification, and drawings being combined ¨ provides sufficient information for a person having ordinary skill in the art to practice the invention as disclosed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure.
[00306] Because of this disclosure and solely because of this disclosure, modification of this device and method can become clear to a person having ordinary skill in this particular art.
Such modifications are clearly covered by this disclosure.
[00307] While the present disclosure describes various embodiments for illustrative purposes, such description is not intended to be limited to such embodiments.
On the contrary, Date Recue/Date Received 2022-02-28 the applicant's teachings described and illustrated herein encompass various alternatives, modifications, and equivalents, without departing from the embodiments, the general scope of which is defined in the appended claims. Except to the extent necessary or inherent in the processes themselves, no particular order to steps or stages of methods or processes described in this disclosure is intended or implied. In many cases the order of process steps may be varied without changing the purpose, effect, or import of the methods described.
[00308] Information as herein shown and described in detail is fully capable of attaining the above-described object of the present disclosure, the presently preferred embodiment of the present disclosure, and is, thus, representative of the subject matter which is broadly contemplated by the present disclosure. The scope of the present disclosure fully encompasses other embodiments which may become apparent to those skilled in the art, and is to be limited, accordingly, by nothing other than the appended claims, wherein any reference to an element being made in the singular is not intended to mean "one and only one"
unless explicitly so stated, but rather "one or more." All structural and functional equivalents to the elements of the above-described preferred embodiment and additional embodiments as regarded by those of ordinary skill in the art are intended to be encompassed by the present claims. Moreover, no requirement exists for a system or method to address each and every problem sought to be resolved by the present disclosure, for such to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. However, that various changes and modifications in form, material, work-piece, and fabrication material detail may be made, without departing from the spirit and scope of the present disclosure, as set forth in the appended claims, as may be apparent to those of ordinary skill in the art, are also encompassed by the disclosure.
Date Recue/Date Received 2022-02-28
.. [0058] In one embodiment, the electric stepper motor further comprises f) a rotary position sensor which can detect an absolute rotary position of the mobile assembly.
[0059] In one embodiment, the rotary position sensor is operably attached to the frequency controller such that the frequency controller can use the absolute rotary position of the mobile assembly to determine when to switch the switching power supply on and off such that the .. mobile assembly moves the target fixed distance.
Date Recue/Date Received 2022-02-28 [0060] Generally, among the many objectives of the present disclosure is the provision of an electric motor with positional sensing. One objective is the provision of an electric motor with positional sensing which uses piezoelectric impulse and permanent magnets as a source of generating mechanical energy from electrical energy. Another objective is the provision of an electric motor with positional sensing which does not use electromagnets and is therefore more efficient and economical to construct. Another objective is the provision of an electric motor with positional sensing which does not use electromagnets and is therefore more efficient and economical to operate. Yet another objective is the provision of an electric motor with positional sensing which does not use electromagnets and is therefore more durable and easier to maintain. Still another objective is the provision of an electric motor with positional sensing which does not use electromagnets and is therefore lighter in weight than a traditional brushless electric motor of equivalent output. The disclosure also provides an electric motor with positional sensing which does not require external detection means and produces a precise measurement of the position and/or motion of the motor. Other advantages and objectives of the electric motor with positional sensing will become clear by reading the application and the disclosures herein.
[0061] In accordance with another aspect of the present disclosure, there is provided an electric motor with positional sensing comprising: a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply; b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets; c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes; d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and e) a counting device, which counts a number of times that one or more of the Date Recue/Date Received 2022-02-28 actuator magnets passes by one or more of the response magnets in turn from a known starting position, such that a relative position of the mobile assembly relative to the known starting position can be determined by using a ratio of an angle swept by a single actuator magnet or a single response magnet to a total diameter of the static assembly, the counting device being able to count the number of times whether the mobile assembly moves relative to the static assembly due to the plurality of piezoelectric actuators being energized by the power supply or due to an external load which imparts an external torque onto one or both of the static assembly or the mobile assembly.
[0062] In one embodiment, the counting device counts the number of times by detecting a back-current when the piezoelectric actuators are not energized by the power supply, the back current caused by the piezoelectric actuators being compressed as the actuator magnets move relative to the response magnets due to the external torque.
[0063] In one embodiment, the group of response magnets comprises a single piece of magnetic material, the single piece of magnetic material having a plurality of magnetic regions, each magnetic region having a local north pole and a local south pole.
[0064] In one embodiment, the electric motor with positional sensing comprises f) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0065] In one embodiment, there are two groups of piezoelectric actuators, further comprising:
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators forming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
[0066] In one embodiment, the electric motor with positional sensing comprises g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and Date Recue/Date Received 2022-02-28 mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0067] In one embodiment, each group of actuator magnets has two ends, and the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group .. of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
[0068] In one embodiment, actuator magnets in each group of actuator magnets are secured by an adhesive, the adhesive securing the actuator magnets in a fixed orientation.
[0069] In one embodiment, there are two groups of piezoelectric actuators, further comprising:
f) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and g) a second group of piezoelectric actuators forming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
[0070] In one embodiment, each group of actuator magnets has two ends, and the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
[0071] In one embodiment, the actuator magnets in each group of actuator magnets are secured by an adhesive, the adhesive securing the actuator magnets in a fixed orientation.
Date Recue/Date Received 2022-02-28 [0072] In one embodiment, the electric motor with positional sensing further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0073] In one embodiment, the electric motor with positional sensing further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0074] In one embodiment, the electric motor with positional sensing further comprises f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0075] In one embodiment, the electric motor with positional sensing further comprises e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0076] In one embodiment, the piezoelectric actuators are electrically connected to the power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by Date Recue/Date Received 2022-02-28 the power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
[0077] In accordance with another aspect of the present disclosure, there is provided an electric motor with positional sensing comprising: a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply; b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets; c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes; d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and e) an induced-current sensor, which detects a back-current, the back-current being induced in the piezoelectric actuators when due to an external load imparting an external torque onto one or both of the static assembly or the mobile assembly, the mobile assembly moves relative to the static assembly.
[0078] In one embodiment, the electric motor with positional sensing further comprises f) a calibration memory device, which can store a plurality of calibration back-current values, the calibration back-current values obtained by using the induced-current sensor to measure the back-current at a plurality of times.
[0079] In one embodiment, the electric motor with positional sensing further comprises g) a calibration load, the calibration load comprising an external driving device which can be removably connected to the electric motor to impart a controllable external torque onto one or the other of the mobile assembly or the static assembly.
Date Recue/Date Received 2022-02-28 [0080] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply.
[0081] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply.
[0082] In one embodiment, the electric motor with positional sensing further comprises g) a position determining device, the position determining device dynamically receiving a plurality of operating back-current values from the induced-current sensor, the position determining device comparing the plurality of operating back-current values to the plurality of calibration back-current values to determine a relative position of the mobile assembly to the static assembly.
[0083] In one embodiment, the electric motor with positional sensing further comprises h) a position determining device, the position determining device dynamically receiving a plurality of operating back-current values from the induced-current sensor, the position determining device comparing the plurality of operating back-current values to the plurality of calibration back-current values to determine a relative position of the mobile assembly to the static assembly.
[0084] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply, and the position determining device compares the first plurality of calibration back-current values and the second plurality of calibration values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
[0085] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the Date Recue/Date Received 2022-02-28 piezoelectric actuators are energized by the power supply, and the position determining device compares the first plurality of calibration back-current values and the second plurality of calibration values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
[0086] In one embodiment, the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply, and the first plurality of calibration back-current values and the second plurality of calibration back-current values are combined into a plurality of average calibration back-current values, and the position determining device compares the plurality of average calibration back-current values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
[0087] In one embodiment, the electric motor with positional sensing further comprises a) a group of elastic members, the elastic members mechanically affixed to at least one of the static or mobile piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
[0088] In one embodiment, the electric motor with positional sensing further comprises f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
[0089] In one embodiment, each group of static magnets and/or each group of mobile magnets is a group of magnets containing at least two magnets, and each group of magnets has two ends, and the magnets in each group of magnets overlap each other to produce a combined magnetic field, and each of the magnets in a group of magnets has a north pole and a south Date Recue/Date Received 2022-02-28 pole, and the south pole of any particular magnet is either physically proximate to one of the two ends, or to the north pole of another magnet in the same group of magnets, and the north pole of any particular magnet is either physically proximate to one of the two ends, or to the south pole of another magnet in the same group of magnets.
[0090] In one embodiment, the piezoelectric actuators are electrically connected to the power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by the power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
BRIEF DESCRIPTION OF THE FIGURES
[0091] Several embodiments of the present disclosure will be provided, by way of examples only, with reference to the appended drawings, wherein:
[0092] FIGURE 1 depicts a perspective view of a magnetic bearing, in accordance with one aspect of the disclosure;
[0093] FIGURE 2 depicts an overhead view of a first alternate embodiment of the magnetic bearing depicted in Figure 1;
[0094] FIGURE 3 depicts a cutaway perspective view of the first alternate embodiment of the magnetic bearing depicted in Figure 2;
[0095] FIGURE 4 depicts a detail view of the interfacing stator and rotor elements of the first alternate embodiment of the magnetic bearing depicted in Figures 2 and 3;
[0096] FIGURE 5 depicts an exploded perspective view of the first alternate embodiment magnetic bearing assembly depicted in Figures 2 to 4;
[0097] FIGURE 6 depicts an overhead view of a second alternate embodiment of the magnetic bearing depicted in Figure 1;
Date Recue/Date Received 2022-02-28 [0098] FIGURE 7 depicts an exploded perspective view of the second alternate magnetic bearing assembly depicted in Figure 6;
[0099] FIGURE 8 depicts an alternate exploded perspective view of the second alternate magnetic bearing assembly depicted in Figures 6 and 7;
[00100] FIGURE 9 depicts a cutaway view of the second alternate magnetic bearing assembly depicted in Figures 6 to 8;
[00101] FIGURE 10 depicts a perspective view of a third alternate embodiment of the magnetic bearing depicted in Figure 1;
[00102] FIGURE 11 depicts a cross-sectional perspective view of the third alternate embodiment of the magnetic bearing depicted in Figure 10;
[00103] FIGURE 12 depicts a perspective view of an electric stepper motor, in accordance with another aspect of the disclosure;
[00104] FIGURE 13 depicts an overhead view of a first alternate embodiment of the electric stepper motor depicted in Figure 12;
[00105] FIGURE 14 depicts a cutaway perspective view of the first alternate embodiment of the electric stepper motor depicted in Figure 13;
[00106] FIGURE 15 depicts a detail view of the interfacing stator and rotor elements of the first alternate embodiment of the electric stepper motor depicted in Figures 13 and 14;
[00107] FIGURE 16 depicts an exploded perspective view of the first alternate embodiment electric stepper motor assembly depicted in Figures 13 to 15;
[00108] FIGURE 17 depicts an overhead view of a second alternate embodiment of the electric stepper motor depicted in Figure 12;
[00109] FIGURE 18 depicts an exploded perspective view of the second alternate electric stepper motor assembly depicted in Figure 17;
[00110] FIGURE 19 depicts an alternate exploded perspective view of the second alternate electric stepper motor assembly depicted in Figures 17 and 18;
Date Recue/Date Received 2022-02-28 [00111] FIGURE 20 depicts a cutaway view of the second alternate electric stepper motor assembly depicted in Figures 17 to 19;
[00112] FIGURE 21 depicts a perspective view of a third alternate embodiment of the electric stepper motor depicted in Figure 12;
[00113] FIGURE 22 depicts a cross-sectional perspective view of the third alternate embodiment of the electric stepper motor depicted in Figure 21;
[00114] FIGURE 23 depicts a perspective view of an electric motor with positional sensing in accordance with another aspect of the disclosure;
[00115] FIGURE 24 depicts an overhead view of a first alternate embodiment of the electric motor with positional sensing depicted in Figure 23;
[00116] FIGURE 25 depicts a cutaway perspective view of the first alternate embodiment of the electric motor with positional sensing depicted in Figure 24;
[00117] FIGURE 26 depicts a detail view of the interfacing stator and rotor elements of the first alternate embodiment electric motor with positional sensing depicted in Figures 24 and 25;
[00118] FIGURE 27 depicts an exploded perspective view of the first alternate embodiment electric motor with positional sensing assembly depicted in Figures 24 to 26;
[00119] FIGURE 28 depicts an overhead view of a second alternate embodiment of the electric motor with positional sensing depicted in Figure 23;
[00120] FIGURE 29 depicts an exploded perspective view of the second alternate electric motor with positional sensing assembly depicted in Figure 28;
[00121] FIGURE 30 depicts an alternate exploded perspective view of the second alternate electric motor with positional sensing assembly depicted in Figures 28 and 29;
[00122] FIGURE 31 depicts a cutaway view of the second alternate electric motor with positional sensing assembly depicted in Figures 28 to 30;
Date Recue/Date Received 2022-02-28 [00123] FIGURE 32 depicts a perspective view of a third alternate embodiment of the electric motor with positional sensing depicted in Figure 23; and [00124] FIGURE 33 depicts a cross-sectional perspective view of the third alternate embodiment of the electric motor with positional sensing depicted in Figure 32.
[00125] In the figures, like reference numerals denote like parts unless the contrary is indicated, as will become apparent from the detailed description.
[00126] Elements in the several figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be emphasized relative to other elements for facilitating understanding of the various presently disclosed embodiments. Also, common, but well-understood elements that are useful or necessary in commercially feasible embodiments are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present disclosure.
DETAILED DESCRIPTION
[00127] Various implementations and aspects of the specification will be described with reference to details discussed below. The following description and drawings are illustrative of the specification and are not to be construed as limiting the specification.
Numerous specific details are described to provide a thorough understanding of various implementations of the present specification. However, in certain instances, well-known or conventional details are not described in order to provide a concise discussion of implementations of the present .. specification.
[00128] Reference will now be made in detail to several embodiments of the disclosure that are illustrated in accompanying drawings. Whenever possible, the same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms such as top, bottom, left, right, up, down, over, above, below, beneath, rear, and front, can be used with respect to the drawings. These and similar directional terms are not to be construed to limit the scope of the disclosure in any manner. The words attach, connect, couple, and similar terms with their inflectional Date Recue/Date Received 2022-02-28 morphemes do not necessarily denote direct or intermediate connections, but can also include connections through mediate elements or devices.
[00129] It should be noted that the sizes and configurations of the preferred embodiment(s) described in the drawings are exaggerated for clarity of disclosure: in actual practice, the tolerances between the elements of embodiments of the disclosure would be much more precise. It is a feature of the disclosure that it allows such very precise tolerances.
[00130] Various aspects of this application include magnetic bearings and electric motors, which will now be described.
MAGNETIC BEARING
[00131] In acccordance with one aspect of the disclosure, a magnetic bearing 10 will now be described in terms of a brushless electric motor such as is disclosed in U.S. Patent Application No. 16/941,477 filed July 28, 2020. The distinction between such a brushless electric motor and a magnetic bearing, in the context of this application, is that the bearing is active even when the motor is not energized, with these additional features:
[00132] If and when the load cannot be rotated at a desired rate by an external driving force, the piezoelectric actuators can be powered to add additional torque and serve as an auxiliary source of power.
[00133] If and when the load begins to rotate faster than is desired, the piezoelectric actuators can be powered to provide torque in the opposite direction of rotation, slowing the rotation of the load.
[00134] The piezoelectric actuators can be used to stabilize the spin of the load without adding any net torque or "drive."
[00135] The piezoelectric actuators can be used to recover some of the energy from the rotation of the load as they will provide a current if the load rotates freely.
[00136] For purposes of this aspect of the disclosure, piezoelectric actuators are described as being "electrically connected" to a power supply. Such a connection can be made via physical conductors (wires, PCB conductive paths, conductive inks, et cetera) or by any Date Recue/Date Received 2022-02-28 other reasonable means that allows the power supply to supply energy to the piezoelectric actuators and causes the piezoelectric effect to change the dimensions of the piezoelectric actuators. This includes, but is not limited to, electromagnetic induction or transfer by capacitance. It is required that the means of electrical connection be able to switch the .. piezoelectric actuators on and off and/or apply a current flow in one direction and then in the other direction fast enough to allow the motor to operate, as will be made clear in the specification below. This will be referred to generally as "rise" time ¨ the period of time it takes to energize the piezoelectric actuator and/or the capacitator powering it ¨ and the "fall"
time ¨ the period of time it takes to deenergize the piezoelectric actuator and/or the capacitor powering it.
[00137] For purposes of this aspect of the disclosure, the magnetic bearing, as embodied in a "motor," will generally have a group of components which remains static relative to a load, and a second group of components which will move relative to the first group of components.
The first group of components will be referred to collectively as a stator assembly, and the second group referred to collectively as a rotor assembly. Prefixing a component with the word "rotor" or "stator" indicates which group of components it belongs to in the embodiment/configuration which is currently being described. Piezoelectric actuators in the stator assembly are stator piezoelectric actuators (or simply stator actuators) and magnets affixed to stator piezoelectric actuators are stator magnets, and vice versa with regard to the rotor assembly.
[00138] At the same time, for purposes of this aspect of the disclosure, magnets can also be described as falling into one or both of two distinct types independent of whether they are part of the stator assembly or the rotor assembly. Actuator magnets are magnets which have/are having force imposed upon them by a piezoelectric actuator. Response magnets are magnets which have/are having force imposed upon them via magnetic field interactions with actuator magnets. If only one group of magnets is affixed to piezoelectric actuators, those are the actuator magnets, and the rest of the magnets in the motor are response magnets. If multiple groups of magnets are affixed to piezoelectric actuators, magnets affixed to a piezoelectric actuator which is being energized and causing it to impose force on those magnets are actuator magnets, and magnets which are not so affixed, or which are affixed to a piezoelectric actuator which is not being energized, are response magnets. It is possible for any given magnet to be an actuator magnet or a response magnet or both at any given time depending on the bearing Date Recue/Date Received 2022-02-28 controller's configuration and energization of the piezoelectric actuators. A
rotor magnet or a stator magnet may at any time be an actuator magnet, a response magnet, or both.
[00139] By referring to FIGURE 1, the basic nature of the magnetic bearing 10 can be easily understood. Outer rotor housing 11 surrounds optional mechanical bearing 12 which is free to rotate on balls 13, which bear the load between the motor and whatever it is mounted in and whatever it is driving.
[00140] It should be clearly understood that in the primary configuration of the magnetic bearing, the mechanical bearing elements (12 and 13) are provided only for supplemental bearing capability. They are not required. The magnetic bearing can function without them.
[00141] Inner rotor element 14 has multiple rotor magnets 15 having rotor north poles 15a and rotor south poles 15b. Any suitable magnet may be used for rotor magnets 15, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare-earth magnetic particles. Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00142] Stator assembly 19 consists of central hub 18, which supports multiple stator piezoelectric actuators 17. Stator piezoelectric actuators 17 have a magnet mount end 17a and a hub end 17b. Stator piezoelectric actuators 17 are connected to a switching power supply (not shown) which can energize the stator piezoelectric actuators at any reasonable driving frequency. When the stator piezoelectric actuators are energized, they expand, using the principle of piezoelectric expansion, also known as the piezoelectric effect, which is well known to persons of ordinary skill in the art. Stator piezoelectric actuators 17 are constructed so that their expansion is along their long axes: in other words, when the stator piezoelectric actuators are energized, the distance between magnet mount end 17b and hub end 17a increases.
[00143] Mounted to magnet mount ends 17b are stator magnets 16, having stator north poles 16a and stator south poles 16b. Any suitable magnet may be used for stator magnets 16, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare- earth magnetic particles. Electromagnets may also be Date Recue/Date Received 2022-02-28 used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00144] It is strongly preferred that the rotor magnets and the stator magnets have the same poles (north and north or south and south) in opposition at their closest points (as shown) but with proper configuration, it is possible to practice the invention with the rotor magnets and the stator magnets having opposite poles (north and south or south and north) in opposition.
If opposite poles are put into opposition, the motor may require an external initiating force and/or the stator piezoelectric actuators may be required to be energized in a staggered sequence. If reversible electromagnets are used for either the rotor magnets, the stator magnets, or both, the question of initial polarities is unimportant.
[00145] The preferred embodiment pictured in FIGURE 1 shows the invention ready to be practiced. The magnetic forces from the rotor magnets and the stator magnets are at a point of equilibrium where the magnets are in the lowest possible potential energy state with regard to the magnetic repulsion between the rotor magnets and the stator magnets.
Inner rotor element 14 will, absent the addition of energy from some exterior source, remain at this point of equilibrium indefinitely.
[00146] To practice this aspect of the disclosure, when a torque of some sort is imposed on the rotor assembly, the rotor may rotate, but the rotor magnets and the stator magnets will .. continue to repel each other, and a controlled, friction free rotation is provided by the bearing.
It should be noted that the components in FIGURE 1 are greatly simplified:
while the bearing as shown in FIGURE 1 would function, in practice the magnetic bearing would have far fewer gaps between the individual rotor magnets and the individual stator magnets (see e.g. FIGURE
6.) [00147] When additional control or torque ¨ either in the same direction of current rotation or opposed to the current rotation ¨ is required, stator piezoelectric actuators 17 are energized. This causes the distance between hub end 17b and magnet mount end 17a to increase, pushing stator magnet 16 closer to rotor magnet 15. This increases the magnetic repulsion between the rotor magnet and the stator magnet, disturbing the equilibrium between them.
Date Recue/Date Received 2022-02-28 [00148] The switching power supply is controlled by a frequency controller (not shown) which causes it to energize and de-energize stator piezoelectric actuators 17 at a frequency which maintains optimal rotational characteristics for the magnetic bearing.
Additional sensors can be linked to the frequency controller to enable such control. For instance, and without limiting the possible control means and methods:
[00149] If transient accelerations are detected, the frequency controller could energize those piezoelectric actuators on the appropriate side of the bearing to push the rotor back into a more centralized orientation, resisting the transient diametric accelerations; and/or [00150] If excessive heat is detected, the frequency controller could de- energize the piezoelectric actuators to increase the overall gap between the stator magnets and the rotor magnets, allowing more air to flow through the gap and provide additional cooling; and/or [00151] If the stator or rotor elements are detected to have expanded or contracted due to thermal changes, the frequency controller could energize or de-energize the piezoelectric actuators as needed to maintain a target gap between the rotor magnets and the stator magnets.
[00152] As is apparent, if desired the frequency controller can energize and de-energize the piezoelectric actuators in ways which can convert magnetic potential energy into rotational energy and accelerate or decelerate inner rotor element 14 in a rotational fashion. It is preferred, but not required, that sensors (not shown) be operably connected to the inner rotor element or otherwise be able to detect its angular velocity, and communicate it to the frequency controller such that the frequency controller can adjust the driving frequency to increase or decrease the force exerted by the stator magnets on the rotor magnets and thus either increase the speed of rotation (under constant load,) increase the applied torque (under increasing load,) or both.
[00153] If such sensors are used, the invention can also be used as an extremely precise stepper motor and/or rotational position sensor. It is preferred, but not required, that a sensor allowing absolute rotational position data also be incorporated into the invention if such a usage is desired. This allows the frequency controller to know where the inner rotor element is at the beginning and the end of a step cycle.
[00154] Once the equilibrium between the rotor magnets and the stator magnets is disturbed, the system will have more magnetic potential energy than before, which will cause Date Recue/Date Received 2022-02-28 the rotor magnets to exert a force on inner rotor 14. Inner rotor element 14 is free to rotate, so it will rotate in one direction or the other as impelled by the balance of forces. As will be shown in later figures, control of the shape and orientation of the rotor magnets and/or stator magnets will allow for a preferred direction of rotation.
[00155] Although the preferred embodiment is described as a magnetic bearing, which is designed to provide a highly controllable magnetic bearing between a load and a fixed base, it will be apparent to persons of ordinary skill in the art that since the piezoelectric effect works both ways ¨ electrical potential can be turned into mechanical force, and mechanical force can be turned into electrical potential ¨ that the preferred embodiment can also serve as a generator of electrical power if an external load forces the inner rotor element to rotate against the magnetic force attempting to hold it in equilibrium. Similarly, the preferred embodiment can also be used as a drive motor which also provides regenerative braking by switching from power in (during drive mode) to power out (during regenerative braking mode.) All of the alternate configurations/embodiments/methods of practice described in this paragraph are applicable to all of the embodiments of the invention disclosed in this application.
[00156] FIGURE 2 shows a first alternate embodiment of the magnetic bearing. The first alternate embodiment of the magnetic bearing works in the same general fashion as the embodiment of FIGURE 1, except where noted otherwise. It likewise would incorporate a switching power supply, frequency controller, and could incorporate sensors, et cetera.
[00157] Magnetic bearing 20 incorporates rotor piezoelectric actuators 27b, analogous to stator piezoelectric actuators 17 in FIGURE 1. Magnetic bearing 20 also incorporates stator piezoelectric actuators 27a. It is neither preferred nor required for either configuration to be applied with a single (inner and outer) group of piezoelectric actuators or a double (inner and outer) group of piezoelectric actuators: the two configurations are shown for clarity of disclosure.
[00158] When either stator piezoelectric actuators 27a or rotor piezoelectric actuators 27b are energized, rotor magnets 25 are pushed toward stator magnets 26, and as in FIGURE
1, magnetic repulsion is increased, incurring a force against the rotor piezoelectric actuators.
As the rotor piezoelectric actuators are affixed to outer casing 21, which is free to rotate relative to hub 29 on optional mechanical bearing 52 (not identified, see FIGURE 5) which includes Date Recue/Date Received 2022-02-28 race 22 containing balls 23, balls 23 bearing the load and allowing rotation of rotary center bearing element 24 relative to fixed center bearing element 28.
[00159] As with the previous embodiment, the elements of mechanical bearing 52 are optional. They are not required, and the magnetic bearing will function without them. They could also serve as a secondary bearing if for whatever reason it was desired that the hub elements could rotate independenly of the rotor elements. It is optional, if such a mechanical bearing is incorporated into the invention, to add mechanical or electrical features that allow it to only rotate in one direction. This would create a mechanical lock between the rotor elements and the hub elements such that the rotor could drive the hub if the rotor is rotating in the same direction as the hub, but if the magnetic bearing fails in such a way as to prevent the magnetic bearing from rotating, the hub elements would be free to rotate and come to a controlled stop, minimizing damage to the magnetic bearing assembly.
[00160] Depending on the desired method of operation, the stator piezoelectric actuators can be activated in concert with the rotor piezoelectric actuators, or only one or the other group of piezoelectric actuators can be active at any given time. If using the magnetic bearing to accelerate or decelerate the load, activating both at once can be used to increase torque/rotational velocity, whereas activating only one or the other can be used for lower output modes. Alternatively, one group of piezoelectric actuators can be wired to deliver input power (motor driving) and the other group wired to receive output power (generation/regenerative braking.) The groups of piezoelectric actuators can also be wired such that some of the actuators in each group are preferentially used to deliver input power and some are preferentially used to receive output power. Finally, all or fewer than all of the piezoelectric actuators in a particular group can be active at any given time to deliver any particular desired amount of input power or receive any particular desired amount of output power, allowing an additional means of controlling power flow and/or reducing electrical fatigue on the individual components as they are cycled in and out of service.
[00161] FIGURE 3 shows the first alternate embodiment in cutaway form.
Magnetic bearing 20, having the same components as in FIGURE 2, is surrounded by backing plate 33 and housing 31, while hollow shaft 32, which is operably affixed to hub 29 (see FIGURE 2) and/or rotary center bearing element 24, allows either delivery of mechanical rotational energy Date Recue/Date Received 2022-02-28 (motor mode) or input of mechanical rotational energy (generation/regenerative braking mode.) [00162] FIGURE 4 shows a pair of opposing piezoelectric actuators and their corresponding magnets in detail. Stator piezoelectric actuator 27b is affixed to stator magnet .. 25 which has stator north pole 25a and stator south pole 25b. Rotor piezoelectric actuator 27a is affixed to rotor magnet 26 which has rotor north pole 26a and rotor south pole 27a. It is preferred, but not required, that the rotor magnets and the stator magnets be asymmetrical to each other (that is, the rotor magnets are not symmetrical with the stator magnets, shown here as their being different sizes) to make it easier to overcome the tendency of the system to "lock"
into a position of minimized magnetic potential energy. Since the magnets are not symmetrical, when they are moved in relation to each other the corresponding magnetic fields will tend to push more in one direction than the other, overcoming such locking symmetry.
[00163] FIGURE 5 shows a more complete assembly of the first alternate embodiment of the invention for clarity of disclosure. Axial bolt 51 holds the assembly together and keeps the rotary elements on-center. Bearing 52 incorporates rotary center bearing element 24, race 22, balls 23, and fixed center bearing element 28. (See FIGURE 2 for more detail.) [00164] FIGURE 6 shows a second alternate embodiment of the magnetic bearing with a more complex configuration of rotor magnets and stator magnets. This configuration, while not required, is somewhat preferred as it provides multiple benefits to the practice of the invention at the price of higher complexity and cost of manufacture.
[00165] Magnetic bearing 60 comprises rotor assembly 614 and stator assembly 618.
Rotably affixing the rotor assembly to the stator assembly is bearing 652 which rotates around central point 611. Mechanically affixed to bearing 652 are one or more stator piezoelectric elements.
[00166] As with the previously described embodiments, the elements of mechanical bearing 652 are optional. They are not required, and the magnetic bearing will function without them.
[00167] Shown is a configuration with six such stator piezoelectric elements including stator piezoelectric element 619. Mechanically affixed to the stator piezoelectric elements are Date Recue/Date Received 2022-02-28 stator magnet elements such as stator magnet element 640. The stator magnet elements comprise one or more magnets having a north pole and a south pole, such as stator magnet 617 having stator magnet north pole 617a and stator magnet south pole 617b. There is a gap between the stator magnet elements and one or more rotor magnet elements.
Shown is a configuration with six such rotor magnet elements including rotor magnet element 642. Each rotor magnet element includes one or more rotor magnets such as rotor magnet 616, which has rotor magnet north pole 616a and rotor magnet south pole 616b.
[00168] It is not required that each rotor magnet element be exactly geometrically opposed to a stator magnet element at any particular time during operation or non-operation and in fact it is likely that the equilibrium during non-operation will result in some degree of offset. It is strongly preferred that there be a rotor magnet element for each stator magnet element, and vice versa. It is required that there be a gap between the rotor magnet elements and the stator magnet elements sufficient to allow the rotor magnet elements to move freely without contacting the stator magnet elements under any reasonable amount of bearing load, rotary speed, or transient vibratory load.
[00169] Although the configuration of magnets shown will be inherently stable due to magnetic attraction between the individual magnets, it is preferred that the magnets in each rotor magnet element and stator magnet element be epoxied or otherwise physically affixed to each other to maintain the desired alignment and prevent shifting under load or due to vibration or other transient phenomena.
[00170] It is strongly preferred, but not required, to use an overlapping configuration of magnets as shown in the rotor magnet elements and the stator magnet elements as this will minimize asymmetries in the overall magnetic field structure in the brushless magnetic motor.
[00171] FIGURE 7 shows a more complete assembly of the second alternate embodiment of the invention for clarity of disclosure along with the addition of an optional set of stator piezoelectric actuators as in FIGURE 2. (See FIGURE 6 for more detail.) Axial bolt 651 holds the assembly together and keeps the elements on-center. Capacitor array bolts 680 affix capacitor array 656 to base element 682 by means of threaded receivers 681. Although shown as traditional capacitive plates, any desired means of capacitive induction of current, such as vacuum-tube capacitors, can be used.
Date Recue/Date Received 2022-02-28 [00172] For purposes of this description, it is assumed that base element 682 is secured to something which is designated as static and therefore base element 682 forms part of a stator assembly. For example, if motor 60 were to be used to bear the load of the wheel of an electric vehicle, base element 682 would ultimately be statically affixed to the chassis of the vehicle, whereas housing 612 would ultimately be statically affixed to the wheel of the vehicle.
[00173] Capacitor array 680, which does not rotate relative to the stator assembly, includes capacitor plates such as capacitor plate 658, each capacitor plate separated by a gap such as capacitor gaps 657a and 657b. Capacitor array energizes rotor piezoelectric array 621, which includes one or more rotor piezoelectric actuators such as rotor piezoelectric actuator 621. The rotor piezoelectric actuators are mechanically affixed to one or more (optional) rotor magnet brackets 678, each rotor magnet bracket having a rotor circumferential surface 662, and (optional) rotor vertical guides 661a and 661b, with all of the rotor magnet brackets forming rotor magnet bracket assembly 660.
[00174] Mechanically affixed to the rotor piezoelectric actuators, either directly or via the (optional) rotor magnet brackets, are one or more rotor magnet elements such as rotor magnet element 642, each rotor magnet element comprising one or more rotor magnets such as rotor magnet 616, with all of the rotor magnet elements forming rotor magnet assembly 672.
[00175] During active operation of the piezoelectric actuators, the rotor piezoelectric actuators are energized, causing them to expand toward the center of motor 60 (since they cannot expand against the fixed position of the rest of the rotor assembly including ultimately housing 612) pushing the rotor magnet elements toward the stator magnet elements (see below) and imparting a magnetic force as explained in previous descriptions (see FIGURES 1, 2, and 6.) The rotor piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The rotor piezoelectric actuators can be energized without energizing the stator piezoelectric actuators (see below) or in concert with them.
[00176] Rotor magnet assembly 672 radially surrounds stator magnet assembly 670, the rotor magnet assembly separated from the stator magnet assembly by a gap (NOT
SHOWN, see FIGURE 9.) Stator magnet assembly 670 comprises one or more stator magnet elements such as stator magnet element 640, each stator magnet element comprising one or more stator Date Recue/Date Received 2022-02-28 magnets such as stator magnet 617. Stator magnet elements are mechanically affixed to stator piezoelectric assembly 669, which includes one or more stator piezoelectric actuators such as stator piezoelectric actuator 619, either directly or by means of (optional) stator magnet bracket assembly 655. (Optional) stator magnet bracket assembly 655 comprises one or more stator magnet brackets such as stator magnet bracket 676, each stator magnet bracket including a stator circumferential surface such as stator circumferential surface 654 and (optional) stator vertical guides 653a and 653b.
[00177] When energized, the stator piezoelectric actuators expand toward the outer circumference of motor 60 (since they cannot expand toward the fixed position of the rest of the stator assembly) pushing the stator magnet elements toward the rotor magnet elements and imparting a magnetic force as explained in previous descriptions (see FIGURES
1, 2, and 6.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632. The stator piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The stator piezoelectric actuators can be energized without energizing the rotor piezoelectric actuators or in concert with them.
[00178] FIGURE 8 shows the configuration of FIGURE 7 in an alternate phase of assembly for clarity of disclosure. Housing 612 is ready to be placed over the rest of the motor assembly, with capacitor array 656 ready to be secured to base element 682 with capacitor array bolts 680. The rotor and stator elements are assembled, for example rotor piezoelectric actuator affixed to rotor circumferential surface 662 and stator piezoelectric actuator affixed to stator circumferential surface 654, and both ready to be inserted into their respective assemblies.
[00179] FIGURE 9 shows the configuration of FIGURE 7 in a cutaway view for clarity of disclosure. Housing 612 is axially secured by axial bolt 651 but is free to rotate relative to base element 682 as they are mechanically connected only by bearings 652 and 683. Rotor magnet element 642 is separated from stator magnet element 640 by gap 690. The size of gap 690 can be changed by energizing stator piezoelectric actuator 619 and/or rotor piezoelectric actuator 621. As the piezoelectric actuators change the size of gap 690, the relative orientation of the magnetic fields of the rotor magnet elements and the stator magnet elements will change.
This will cause magnetic force to be exerted between magnet elements, but as only the rotor Date Recue/Date Received 2022-02-28 magnet elements (ultimately connected to housing 612) can move, the force will cause housing 612 to move, allowing rotary motion to be imparted to hollow shaft 632 and thus to an axle, a wheel, or any other rotary member or rotary load desired.
[00180] FIGURE 10 shows a third alternate embodiment of this aspect of the invention.
In this embodiment, rather than a plurality of distinctive magnets, the rotor magnets comprise a single piece of rotor magnetic material, which is structured to have a plurality of magnetic regions, each magnetic region having a north pole and a south pole. Similarly, there are two individual pieces of stator magnetic material having a plurality of magnetic regions. Each piece of stator magnetic material is attached to one end of a single piezoelectric actuator.
[00181] Magnetic bearing 80 comprises rotor assembly 82, stator magnet assemblies 84 and 87, and piezoelectric actuator 810 which is operably affixed to PCB 92 (NOT SHOWN:
See FIGURE 11.) Rotor assembly 82, which is free to rotate relative to all stator assembly components and is attached to whatever rotational load (NOT SHOWN) it is desired to bear with the bearing, is comprised of magnetic material (or can have an inner section of magnetic material surrounded by non-magnetic material as desired) which has magnetic regions, each magnetic region having a north pole and a south pole such as rotor north poles 82a and 82b and rotor south poles 83a and 83b. Opposite the rotor assembly's magnetic material, separated by a gap (See FIGURE 11) are stator magnet assemblies 84 and 87. It is possible to construct this embodiment of the invention with a single stator magnet assembly, but it is strongly preferred to use two symmetrical stator magnet assemblies as shown for purposes of balance and to maximize the piezoelectric actuator's efficiency. First stator magnet assembly 84, similarly to rotor section 82, is composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and rotor south poles 86a and 86b. Second stator magnet assembly 87, is likewise composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and stator south poles 86a and 86b.
[00182] FIGURE 11 shows a cutaway view of the third alternate embodiment of this aspect of the invention for additional clarity of disclosure. Magnetic bearing 80 has gap 91, which separates the various stator and rotor assemblies (see FIGURE 10) and allows the magnetic bearing to serve as a no-contact magnetic bearing so long as the planar load does not Date Recue/Date Received 2022-02-28 materially affect the gap as maintained by the magnet assembly and the stator magnet assemblies. This is an additional advantage of several of the embodiments and configurations of the invention disclosed herein. PCB 92 is a printed circuit board which is both mechanically and electrically affixed to piezoelectric actuator 810 and provides it with electrical potential from a switching power supply (NOT SHOWN).
[00183] If necessary, fluid can be forcibly circulated around the assemblies or even through the gap to cool the motor, but as many piezoelectric devices actually work better when they reach a relatively high operating temperature, the need for cooling will be minimal in many applications. This is another advantage of the invention. It is required that for all embodiments and configurations of the invention, that operating temperatures be kept low enough to avoid demagnetization of any permanent magnets which are used. This will vary as various kinds of magnetic material have different demagnetization thresholds.
(For example, some ferrite magnets can tolerate temperatures up to 250 C, whereas some rare-earth magnets can only tolerate temperatures up to 100 C.) [00184] To practice an embodiment of this aspect of the invention, an electrical potential is put across piezoelectric actuator 810, which is electrically connected to PCB 92. This causes piezoelectric actuator 810 to expand along its long axis, changing the relative position of the stator magnet assemblies and the rotor assembly. This in turn causes electromagnetic force to be exerted on the rotor assembly, which will rotate to a position which will minimize the magnetic potential energy between the rotor assembly and the stator assemblies. The electrical potential across piezoelectric actuator 810, is then removed and/or reversed, causing it to contract along its long axis, again changing the relative position of the various magnet assemblies. A switching power supply (NOT SHOWN) continuously cycles the electrical potential across the piezoelectric actuator to produce the desired magnetic bearing load and/or acceleration or deceleration as in previously described embodiments.
[00185] It is optional, but neither preferred nor required, for either the rotor assembly or the stator assembly, or both, to comprise multiple magnets as in earlier described configurations. (See FIGURE 1, FIGURE 2, and/or FIGURE 6.) So long as the rotor assembly and the stator assembly are configured as shown, the configuration of this third alternate embodiment incorporating a single piezoelectric actuator will function and provide the benefits of the invention.
Date Recue/Date Received 2022-02-28 [00186] Alternate configurations of this aspect of the disclosure, which can be applied to any of the described embodiments, will now be disclosed.
[00187] In a first alternate configuration of this aspect (NOT SHOWN) some or all of the rotor magnets, or some or all of the stator magnets, of either the preferred embodiment or the first alternate embodiment are replaced with electromagnets.
[00188] In a second alternate configuration of this aspect (NOT SHOWN) one or more elastic members is fitted into the motor assembly such that the piezoelectric actuators are working against the elastic members when they are energized, compressing them and creating elastic potential energy, so that when the piezoelectric actuator(s) is/are de-energized, the magnet(s) affixed to the piezoelectric actuator(s) return to their prior position more quickly and without the need to impose a reverse polarity potential across the piezoelectric actuator when the elastic potential energy provides impetus to the piezoelectric actuators.
[00189] In a third alternate configuration of this aspect (NOT SHOWN), the features of the first and second configurations are combined.
[00190] It will be apparent to those of ordinary skill in the art that while the invention and its preferred embodiments are described in terms of rotary bearings, the principles taught by the invention can be used to create linear bearings, such as reciprocating bearings, by using the basic principle of piezoelectric motivation of opposing magnetic elements to create a magnetic repulsion along a linear bearing interface instead of a rotary bearing interface. Thus, .. the claims below include both rotary configurations and linear configurations where and as appropriate.
ELECTRIC STEPPER MOTOR
[00191] In acccordance with another aspect of the disclosure, an electric stepper motor 10 will now be described.
[00192] For purposes of this aspect of the disclosure, piezoelectric actuators are described as being "electrically connected" to a switching power supply. Such a connection can be made via physical conductors (wires, PCB conductive paths, conductive inks, et cetera) or by any other reasonable means that allows the switching power supply to supply energy to the piezoelectric actuators and causes the piezoelectric effect to change the dimensions of the Date Recue/Date Received 2022-02-28 piezoelectric actuators. This includes, but is not limited to, electromagnetic induction or transfer by capacitance. It is required that the means of electrical connection be able to switch the piezoelectric actuators on and off and/or apply a current flow in one direction and then in the other direction fast enough to allow the motor to operate, as will be made clear in the specification below. This will be referred to generally as "rise" time ¨ the period of time it takes to energize the piezoelectric actuator and/or the capacitator powering it ¨ and the "fall"
time ¨ the period of time it takes to deenergize the piezoelectric actuator and/or the capacitor powering it.
[00193] For purposes of this aspect of the disclosure, motors will generally have a group of components which remains static relative to a load, and a second group of components which will move relative to the first group of components. The first group of components will be referred to collectively as a stator assembly, and the second group referred to collectively as a rotor assembly. Prefixing a component with the word "rotor" or "stator"
indicates which group of components it belongs to in the embodiment/configuration which is currently being described. Piezoelectric actuators in the stator assembly are stator piezoelectric actuators (or simply stator actuators) and magnets affixed to stator piezoelectric actuators are stator magnets, and vice versa with regard to the rotor assembly.
[00194] At the same time, for purposes of this aspect of the disclosure, magnets can also be described as falling into one or both of two distinct types independent of whether they are part of the stator assembly or the rotor assembly. Actuator magnets are magnets which have/are having force imposed upon them by a piezoelectric actuator. Response magnets are magnets which have/are having force imposed upon them via magnetic field interactions with actuator magnets. If only one group of magnets is affixed to piezoelectric actuators, those are the actuator magnets, and the rest of the magnets in the motor are response magnets. If multiple groups of magnets are affixed to piezoelectric actuators, magnets affixed to a piezoelectric actuator which is being energized and causing it to impose force on those magnets are actuator magnets, and magnets which are not so affixed, or which are affixed to a piezoelectric actuator which is not being energized, are response magnets. It is possible for any given magnet to be an actuator magnet or a response magnet or both at any given time depending on the motor controller's configuration and energization of the piezoelectric actuators. A
rotor magnet or a stator magnet may at any time be an actuator magnet, a response magnet, or both.
Date Recue/Date Received 2022-02-28 [00195] By referring to FIGURE 12, the basic nature of this aspect of the disclosure can be easily understood. Outer rotor housing 11 surrounds bearing 12 which is free to rotate on balls 13, which bear the load between the motor and whatever it is mounted in and whatever it is driving. Inner rotor element 14 has multiple rotor magnets 15 having rotor north poles 15a and rotor south poles 15b. Any suitable magnet may be used for rotor magnets 15, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare- earth magnetic particles. Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00196] Stator assembly 19 consists of central hub 18, which supports multiple stator piezoelectric actuators 17. Stator piezoelectric actuators 17 have a magnet mount end 17a and a hub end 17b. Stator piezoelectric actuators 17 are connected to a switching power supply (not shown) which can energize the stator piezoelectric actuators at any reasonable driving frequency. When the stator piezoelectric actuators are energized, they expand, using the principle of piezoelectric expansion, also known as the piezoelectric effect, which is well known to persons of ordinary skill in the art. Stator piezoelectric actuators 17 are constructed so that their expansion is along their long axes: in other words, when the stator piezoelectric actuators are energized, the distance between magnet mount end 17b and hub end 17a increases.
[00197] Mounted to magnet mount ends 17b are stator magnets 16, having stator north poles 16a and stator south poles 16b. Any suitable magnet may be used for stator magnets 16, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare- earth magnetic particles. Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00198] It is strongly preferred that the rotor magnets and the stator magnets have the same poles (north and north or south and south) in opposition at their closest points (as shown) but with proper configuration, it is possible to practice the invention with the rotor magnets and the stator magnets having opposite poles (north and south or south and north) in opposition.
Date Recue/Date Received 2022-02-28 If opposite poles are put into opposition, the motor may require an external initiating force and/or the stator piezoelectric actuators may be required to be energized in a staggered sequence. If reversible electromagnets are used for either the rotor magnets, the stator magnets, or both, the question of initial polarities is unimportant.
[00199] The preferred embodiment pictured in FIGURE 12 shows the invention ready to be practiced. The magnetic forces from the rotor magnets and the stator magnets are at a point of equilibrium where the magnets are in the lowest possible potential energy state with regard to the magnetic repulsion between the rotor magnets and the stator magnets. Inner rotor element 14 will, absent the addition of energy from some exterior source, remain at this point of equilibrium indefinitely.
[00200] To practice the invention, stator piezoelectric actuators 17 are energized. This causes the distance between hub end 17b and magnet mount end 17a to increase, pushing stator magnet 16 closer to rotor magnet 15. This increases the magnetic repulsion between the rotor magnet and the stator magnet, disturbing the equilibrium between them. In the configuration shown, it may be necessary to impart a slight initial rotational force and/or to energize the stator piezoelectric actuators in sequence so as to asymmetrically disturb the equilibrium of magnetic forces and allow rotation to begin.
[00201] Once the equilibrium between the rotor magnets and the stator magnets is disturbed, the system will have more magnetic potential energy than before, which will cause the rotor magnets to exert a force on inner rotor 14. Inner rotor element 14 is free to rotate, so it will rotate in one direction or the other as impelled by the balance of forces. As will be shown in later figures, control of the shape and orientation of the rotor magnets and/or stator magnets will allow for a preferred direction of rotation.
[00202] The switching power supply is controlled by a frequency controller (not shown) which causes it to energize and de-energize stator piezoelectric actuators 17 at a frequency which will continue to convert magnetic potential energy into rotational energy and accelerate inner rotor element 14 in a rotational fashion. It is preferred, but not required, that sensors (not shown) be operably connected to the inner rotor element or otherwise be able to detect its angular velocity, and communicate it to the frequency controller such that the frequency controller can adjust the driving frequency to increase or decrease the force exerted by the Date Recue/Date Received 2022-02-28 stator magnets on the rotor magnets and thus either increase the speed of rotation (under constant load,) increase the applied torque (under increasing load,) or both.
[00203] If such sensors are used, the utility of the invention as a precise stepper motor is further increased. It is preferred, but not required, that a sensor allowing absolute rotational position data also be incorporated into the invention if such a usage is desired. This allows the frequency controller to know where the inner rotor element is at the beginning and the end of a step cycle.
[00204]
With or without the sensors, the switching power supply energizes and de-energizes the stator piezoelectric actuators, with each energization/de-energization cycle imparting a fixed amount of energy into the rotation of the motor. Since the geometry of the stator magnets and the rotor magnets is known, in its simplest embodiment, the invention can be practiced as a stepper motor simply by sending a single energization/de-energization pulse to the stator piezoelectric actuators. This will cause the motor assembly to rotate through the arc-section occupied by a single set of opposing rotor/stator magnets. Once the stator piezoelectric actuators are de-energized, magnetic repulsion between the rotor magnets and the stator magnets will cause the rotation of the rotor to stop as the rotor magnets will not want to move "past" the stator magnets absent the impulse provided by the stator piezoelectric actuators. To get additional fractional rotations, additional energization/de-energization pulses can be sent, which will each produce an additional single rotation through such arc-section.
[00205] If the rotor and the external load on the rotor have too much inertia for the rotor and stator magnets to stop the rotor after the energization/de- energization cycles stop by simple magnetic repulsion, multiple methods of further precisely controlling the rotation of the electric stepper motor may be applied, including but not limited to:
1) It is preferred to use the stator piezoelectric actuators to apply a braking force to the rotor. The frequency controller can be used to cause the stator piezoelectric actuators to push the stator magnets toward the rotor magnets at the point in their rotation where it would tend to slow the rotation of the rotor, not accelerate it. As modern frequency controllers and switching power supplies are capable of very fast and very precise control of electrical circuits, this can provide very precise control of the acceleration/braking of the electric stepper motor.
Date Recue/Date Received 2022-02-28 2) An external brake (not shown) of some kind can be engaged whenever the stepper motor is not desired to be moving, such that as soon as the stator piezoelectric actuators are not being energized, sufficient friction to stop the rotation of the rotor (and the external load) is applied.
[00206] Although the preferred embodiment is described as an electric stepper motor, which is designed to convert electrical potential from a switching power supply into rotational energy, it will be apparent to persons of ordinary skill in the art that since the piezoelectric effect works both ways ¨ electrical potential can be turned into mechanical force, and mechanical force can be turned into electrical potential ¨ that the preferred embodiment can also serve as a generator of electrical power if an external load forces the inner rotor element to rotate against the magnetic force attempting to hold it in equilibrium.
[00207]
Similarly, the preferred embodiment can also be used as a drive motor which also provides regenerative braking by switching from power in (during drive mode) to power out (during regenerative braking mode.) All of the alternate configurations/embodiments/methods of practice described in this paragraph are applicable to all of the embodiments of the invention disclosed in this application.
[00208]
Additional embodiments of the electric stepper motor will now be described.
All of the additional embodiments are alternate configurations of the physical motor itself: the principles by which each embodiment can be used as an electric stepper motor is identical to that described above.
[00209]
FIGURE 13 shows a first alternate embodiment of the electric stepper motor.
The first alternate embodiment of the electric stepper motor works in the same general fashion as the embodiment of FIGURE 12, except where noted otherwise. It likewise would incorporate a switching power supply, frequency controller, and could incorporate sensors, et cetera.
[00210]
Electric stepper motor 20 incorporates rotor piezoelectric actuators 27b, analogous to stator piezoelectric actuators 17 in FIGURE 12. Electric stepper motor 20 also incorporates stator piezoelectric actuators 27a. It is neither preferred nor required for either configuration to be applied with a single (inner and outer) group of piezoelectric actuators or a Date Recue/Date Received 2022-02-28 double (inner and outer) group of piezoelectric actuators: the two configurations are shown for clarity of disclosure.
[00211] When either stator piezoelectric actuators 27a or rotor piezoelectric actuators 27b are energized, rotor magnets 25 are pushed toward stator magnets 26, and as in FIGURE
.. 12, magnetic repulsion is increased, incurring a force against the rotor piezoelectric actuators.
As the rotor piezoelectric actuators are affixed to outer casing 21, which is free to rotate relative to hub 29 on bearing 52 (not identified, see FIGURE 16) which includes race 22 containing balls 23, balls 23 bearing the load and allowing rotation of rotary center bearing element 24 relative to fixed center bearing element 28.
[00212] Depending on the desired method of operation, the stator piezoelectric actuators can be activated in concert with the rotor piezoelectric actuators, or only one or the other group of piezoelectric actuators can be active at any given time. Activating both at once can be used to increase torque/rotational velocity, whereas activating only one or the other can be used for lower output modes. Alternatively, one group of piezoelectric actuators can be wired to deliver input power (motor driving) and the other group wired to receive output power (generation/regenerative braking.) The groups of piezoelectric actuators can also be wired such that some of the actuators in each group are preferentially used to deliver input power and some are preferentially used to receive output power. Finally, all or fewer than all of the piezoelectric actuators in a particular group can be active at any given time to deliver any particular desired amount of input power or receive any particular desired amount of output power, allowing an additional means of controlling power flow and/or reducing electrical fatigue on the individual components as they are cycled in and out of service.
[00213] FIGURE 14 shows the first alternate embodiment in cutaway form.
Electric stepper motor 20, having the same components as in FIGURE 13, is surrounded by backing plate 33 and housing 31, while hollow shaft 32, which is operably affixed to hub 29 (see FIGURE 13) and/or rotary center bearing element 24, allows either delivery of mechanical rotational energy (motor mode) or input of mechanical rotational energy (generation/regenerative braking mode.) [00214] FIGURE 15 shows a pair of opposing piezoelectric actuators and their corresponding magnets in detail. Stator piezoelectric actuator 27b is affixed to stator magnet Date Recue/Date Received 2022-02-28 25 which has stator north pole 25a and stator south pole 25b. Rotor piezoelectric actuator 27a is affixed to rotor magnet 26 which has rotor north pole 26a and rotor south pole 27a. It is preferred, but not required, that the rotor magnets and the stator magnets be asymmetrical to each other (that is, the rotor magnets are not symmetrical with the stator magnets, shown here as their being different sizes) to make it easier to overcome the tendency of the system to "lock"
into a position of minimized magnetic potential energy. Since the magnets are not symmetrical, when they are moved in relation to each other the corresponding magnetic fields will tend to push more in one direction than the other, overcoming such locking symmetry.
However, if it is desired to mainly use pure magnetic repulsion as a braking force for steps of the stepper motor, it may be preferred to make the magnets as symmetrical as possible so as to maximize the efficiency of the individual attraction/repulsion of the individual rotor magnet/stator magnet pairs.
[00215] FIGURE 16 shows a more complete assembly of the first alternate embodiment of the invention for clarity of disclosure. Axial bolt 51 holds the assembly together and keeps the rotary elements on-center. Bearing 52 incorporates rotary center bearing element 24, race 22, balls 23, and fixed center bearing element 28. (See FIGURE 13 for more detail.) [00216] FIGURE 17 shows a second alternate embodiment of the electric stepper motor with a more complex configuration of rotor magnets and stator magnets. This configuration, while not required, is somewhat preferred as it provides multiple benefits to the practice of the invention at the price of higher complexity and cost of manufacture.
[00217] Electric stepper motor 60 comprises rotor assembly 614 and stator assembly 618. Rotably affixing the rotor assembly to the stator assembly is bearing 652 which rotates around central point 611. Mechanically affixed to bearing 652 are one or more stator piezoelectric elements. Shown is a configuration with six such stator piezoelectric elements including stator piezoelectric element 619. Mechanically affixed to the stator piezoelectric elements are stator magnet elements such as stator magnet element 640. The stator magnet elements comprise one or more magnets having a north pole and a south pole, such as stator magnet 617 having stator magnet north pole 617a and stator magnet south pole 617b. There is a gap between the stator magnet elements and one or more rotor magnet elements. Shown is a configuration with six such rotor magnet elements including rotor magnet element 642. Each Date Recue/Date Received 2022-02-28 rotor magnet element includes one or more rotor magnets such as rotor magnet 616, which has rotor magnet north pole 616a and rotor magnet south pole 616b.
[00218] To practice this aspect of the invention, as with prior described embodiments, one or more of the stator piezoelectric actuators, such as stator piezoelectric actuator 619, is energized by a switching power supply (NOT SHOWN) controlled by a frequency controller (NOT SHOWN) such that when, for example, stator piezoelectric actuator 619 is energized, it expands along axis of expansion 619a, causing the corresponding stator magnet element to get closer to one or more rotor magnet elements. This produces a change in the orientation of the magnetic fields of the stator and rotor magnetic elements, causing the corresponding stator magnetic element to exert a force on the rotor magnetic element which in turn causes the rotor magnet element to exert a force on the housing 612, causing it, along with the entire rotor assembly 614 to rotate around central point 611 on bearing 652 relative to stator assembly 618.
This rotational force is transmitted to an external load via hollow shaft 632 (NOT SHOWN, see FIGURE 18.) [00219] It is not required that each rotor magnet element be exactly geometrically opposed to a stator magnet element at any particular time during operation or non-operation and in fact it is likely that the equilibrium during non-operation will result in some degree of offset. It is strongly preferred that there be a rotor magnet element for each stator magnet element, and vice versa. It is required that there be a gap between the rotor magnet elements and the stator magnet elements sufficient to allow the rotor magnet elements to move freely without contacting the stator magnet elements under any reasonable amount of bearing load, rotary speed, or transient vibratory load.
[00220] Although the configuration of magnets shown will be inherently stable due to magnetic attraction between the individual magnets, it is preferred that the magnets in each rotor magnet element and stator magnet element be epoxied or otherwise physically affixed to each other to maintain the desired alignment and prevent shifting under load or due to vibration or other transient phenomena.
[00221] It is strongly preferred, but not required, to use an overlapping configuration of magnets as shown in the rotor magnet elements and the stator magnet elements as this will minimize asymmetries in the overall magnetic field structure in the brushless magnetic motor.
Date Recue/Date Received 2022-02-28 [00222] FIGURE 18 shows a more complete assembly of the second alternate embodiment of the invention for clarity of disclosure along with the addition of an optional set of stator piezoelectric actuators as in FIGURE 13. (See FIGURE 17 for more detail.) Axial bolt 651 holds the assembly together and keeps the elements on-center. Capacitor array bolts 680 affix capacitor array 656 to base element 682 by means of threaded receivers 681. Although shown as traditional capacitive plates, any desired means of capacitive induction of current, such as vacuum-tube capacitors, can be used.
[00223] For purposes of this description, it is assumed that base element 682 is secured to something which is designated as static and therefore base element 682 forms part of a stator assembly. For example, if motor 60 were to be used to drive a turntable, base element 682 would ultimately be statically affixed to the base assembly of the turntable, whereas housing 612 would ultimately be statically affixed to the turntable itself.
[00224] Capacitor array 680, which does not rotate relative to the stator assembly, includes capacitor plates such as capacitor plate 658, each capacitor plate separated by a gap such as capacitor gaps 657a and 657b. Capacitor array energizes rotor piezoelectric array 621, which includes one or more rotor piezoelectric actuators such as rotor piezoelectric actuator 621. The rotor piezoelectric actuators are mechanically affixed to one or more (optional) rotor magnet brackets 678, each rotor magnet bracket having a rotor circumferential surface 662, and (optional) rotor vertical guides 661a and 661b, with all of the rotor magnet brackets forming rotor magnet bracket assembly 660. Mechanically affixed to the rotor piezoelectric actuators, either directly or via the (optional) rotor magnet brackets, are one or more rotor magnet elements such as rotor magnet element 642, each rotor magnet element comprising one or more rotor magnets such as rotor magnet 616, with all of the rotor magnet elements forming rotor magnet assembly 672.
[00225] When energized, the rotor piezoelectric actuators expand toward the center of motor 60 (since they cannot expand against the fixed position of the rest of the rotor assembly including ultimately housing 612) pushing the rotor magnet elements toward the stator magnet elements (see below) and imparting a magnetic force as explained in previous descriptions (see FIGURES 12, 13, and 17.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632.
The rotor piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired Date Recue/Date Received 2022-02-28 and appropriate for the load and conditions. The rotor piezoelectric actuators can be energized without energizing the stator piezoelectric actuators (see below) or in concert with them.
[00226] Rotor magnet assembly 672 radially surrounds stator magnet assembly 670, the rotor magnet assembly separated from the stator magnet assembly by a gap (NOT
SHOWN, see FIGURE 20.) Stator magnet assembly 670 comprises one or more stator magnet elements such as stator magnet element 640, each stator magnet element comprising one or more stator magnets such as stator magnet 617. Stator magnet elements are mechanically affixed to stator piezoelectric assembly 669, which includes one or more stator piezoelectric actuators such as stator piezoelectric actuator 619, either directly or by means of (optional) stator magnet bracket assembly 655. (Optional) stator magnet bracket assembly 655 comprises one or more stator magnet brackets such as stator magnet bracket 676, each stator magnet bracket including a stator circumferential surface such as stator circumferential surface 654 and (optional) stator vertical guides 653a and 653b.
[00227] When energized, the stator piezoelectric actuators expand toward the outer circumference of motor 60 (since they cannot expand toward the fixed position of the rest of the stator assembly) pushing the stator magnet elements toward the rotor magnet elements and imparting a magnetic force as explained in previous descriptions (see FIGURES
12, 13, and 17.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632. The stator piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The stator piezoelectric actuators can be energized without energizing the rotor piezoelectric actuators or in concert with them.
[00228] FIGURE 19 shows the configuration of FIGURE 18 in an alternate phase of assembly for clarity of disclosure. Housing 612 is ready to be placed over the rest of the motor assembly, with capacitor array 656 ready to be secured to base element 682 with capacitor array bolts 680. The rotor and stator elements are assembled, for example rotor piezoelectric actuator affixed to rotor circumferential surface 662 and stator piezoelectric actuator affixed to stator circumferential surface 654, and both ready to be inserted into their respective assemblies.
Date Recue/Date Received 2022-02-28 [00229] FIGURE 20 shows the configuration of FIGURE 18 in a cutaway view for clarity of disclosure. Housing 612 is axially secured by axial bolt 651 but is free to rotate relative to base element 682 as they are mechanically connected only by bearings 652 and 683.
Rotor magnet element 642 is separated from stator magnet element 640 by gap 690. The size of gap 690 can be changed by energizing stator piezoelectric actuator 619 and/or rotor piezoelectric actuator 621. As the piezoelectric actuators change the size of gap 690, the relative orientation of the magnetic fields of the rotor magnet elements and the stator magnet elements will change. This will cause magnetic force to be exerted between magnet elements, but as only the rotor magnet elements (ultimately connected to housing 612) can move, the .. force will cause housing 612 to move, allowing rotary motion to be imparted to hollow shaft 632 and thus to an axle, a wheel, or any other rotary member or rotary load desired.
[00230] FIGURE 21 shows a third alternate embodiment of the invention.
In this embodiment, rather than a plurality of distinctive magnets, the rotor magnets comprise a single piece of rotor magnetic material, which is structured to have a plurality of magnetic regions, each magnetic region having a north pole and a south pole. Similarly, there are two individual pieces of stator magnetic material having a plurality of magnetic regions.
Each piece of stator magnetic material is attached to one end of a single piezoelectric actuator.
As shown, the rotational precision of the electric stepper motor would not be high, and it would not be possible to make this embodiment as precise as the previously described embodiments due to the inherent properties of the type of magnetic material used. It is preferred to use this embodiment of the invention in applications where fine control is less important than simplicity and lower cost.
[00231] Electric stepper motor 80 comprises rotor assembly 82, stator magnet assemblies 84 and 87, and piezoelectric actuator 810 which is operably affixed to PCB 92 (NOT SHOWN: See FIGURE 22.) Rotor assembly 82, which is free to rotate relative to all stator assembly components and is attached to whatever rotational load (NOT
SHOWN) it is desired to accelerate with the motor, is comprised of magnetic material (or can have an inner section of magnetic material surrounded by non-magnetic material as desired) which has magnetic regions, each magnetic region having a north pole and a south pole such as rotor north poles 82a and 82b and rotor south poles 83a and 83b. Opposite the rotor assembly's magnetic material, separated by a gap (See FIGURE 22,) are stator magnet assemblies 84 and 87. It is possible to construct this embodiment of the invention with a single stator magnet Date Recue/Date Received 2022-02-28 assembly, but it is strongly preferred to use two symmetrical stator magnet assemblies as shown for purposes of balance and to maximize the piezoelectric actuator's efficiency.
[00232] First stator magnet assembly 84, similarly to rotor section 82, is composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and rotor south poles 86a and 86b. Second stator magnet assembly 87, is likewise composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and stator south poles 86a and 86b.
[00233] FIGURE 22 shows a cutaway view of the third alternate embodiment of the invention for additional clarity of disclosure. Electric stepper motor 80 has gap 91, which separates the various motor assemblies (see FIGURE 21) and allows the motor to also serve as a no-contact magnetic bearing so long as the planar load does not materially affect the gap as maintained by the magnetic fields of the rotor magnet assembly and the stator magnet assemblies. This is an additional advantage of several of the embodiments and configurations of the invention disclosed herein. PCB 92 is a printed circuit board which is both mechanically and electrically affixed to piezoelectric actuator 810 and provides it with electrical potential from a switching power supply (NOT SHOWN.) [00234] To practice this aspect of the invention, an electrical potential is put across piezoelectric actuator 810, which is electrically connected to PCB 92. This causes piezoelectric actuator 810 to expand along its long axis, changing the relative position of the stator magnet assemblies and the rotor assembly.
[00235] This in turn causes electromagnetic force to be exerted on the rotor assembly, which will rotate to a position which will minimize the magnetic potential energy between the rotor assembly and the stator assemblies. The electrical potential across piezoelectric actuator 810, is then removed and/or reversed, causing it to contract along its long axis, again changing the relative position of the various magnet assemblies, and imparting more rotational energy to the rotor assembly. A switching power supply (NOT SHOWN) continuously cycles the electrical potential across the piezoelectric actuator to produce the desired rotational energy as in earlier described embodiments.
Date Recue/Date Received 2022-02-28 [00236] It is optional, but neither preferred nor required, for either the rotor assembly or the stator assembly, or both, to comprise multiple magnets as in earlier described configurations. (See FIGURE 12, FIGURE 13, and/or FIGURE 17.) So long as the rotor assembly and the stator assembly are configured as shown, the configuration of this third alternate embodiment incorporating a single piezoelectric actuator will function and provide the benefits of the invention.
[00237] Alternate configurations of this aspect the invention, which can be applied to any of the described embodiments, will now be disclosed.
[00238] In a first alternate configuration of this aspect (NOT SHOWN) some or all of .. the rotor magnets, or some or all of the stator magnets, of either the preferred embodiment or the first alternate embodiment are replaced with electromagnets.
[00239] In a second alternate configuration of this aspect (NOT SHOWN) one or more elastic members is fitted into the motor assembly such that the piezoelectric actuators are working against the elastic members when they are energized, compressing them and creating .. elastic potential energy, so that when the piezoelectric actuator(s) is/are de-energized, the magnet(s) affixed to the piezoelectric actuator(s) return to their prior position more quickly and without the need to impose a reverse polarity potential across the piezoelectric actuator when the elastic potential energy provides impetus to the piezoelectric actuators.
[00240] In a third alternate configuration of this aspect (NOT SHOWN) the features of the first and second configurations are combined.
[00241] In many of the described embodiments and if necessary, fluid can be forcibly circulated around the assemblies or even through the gap(s) to cool the motor, but as many piezoelectric devices actually work better when they reach a relatively high operating temperature, the need for cooling will be minimal in many applications. This is another advantage of the invention. It is required that for all embodiments and configurations of the invention, that operating temperatures be kept low enough to avoid demagnetization of any permanent magnets which are used. This will vary as various kinds of magnetic material have different demagnetization thresholds. (For example, some ferrite magnets can tolerate temperatures up to 250 C, whereas some rare-earth magnets can only tolerate temperatures up .. to 100 C.) Date Recue/Date Received 2022-02-28 [00242] It will be apparent to those of ordinary skill in the art that while this aspect of the invention and its preferred embodiments are described in terms of rotary motors, the principles taught by the invention can be used to create linear motors, such as reciprocating motors, by using the basic principle of piezoelectric motivation of opposing magnetic elements to create a linear force instead of a centripetal force. Thus, the claims below include both rotary configurations and linear configurations where and as appropriate.
ELECTRIC MOTOR WITH POSITIONAL SENSING
[00243] In acccordance with another aspect of the disclosure, an electric motor with positional sensing 10 will now be described.
[00244] For purposes of this aspect, piezoelectric actuators are described as being "electrically connected" to a power supply. Such a connection can be made via physical conductors (wires, PCB conductive paths, conductive inks, etcetera) or by any other reasonable means that allows the power supply to supply energy to the piezoelectric actuators and causes the piezoelectric effect to change the dimensions of the piezoelectric actuators. This includes, but is not limited to, electromagnetic induction or transfer by capacitance.
It is required that the means of electrical connection be able to switch the piezoelectric actuators on and off and/or apply a current flow in one direction and then in the other direction fast enough to allow the motor to operate, as will be made clear in the specification below. This will be referred to generally as "rise" time ¨ the period of time it takes to energize the piezoelectric actuator and/or the capacitator powering it ¨ and the "fall" time ¨ the period of time it takes to deenergize the piezoelectric actuator and/or the capacitor powering it.
[00245] For purposes of this aspect, motors will generally have a group of components which remains static relative to a load, and a second group of components which will move relative to the first group of components. The first group of components will be referred to collectively as a stator assembly, and the second group referred to collectively as a rotor assembly. Prefixing a component with the word "rotor" or "stator" indicates which group of components it belongs to in the embodiment/configuration which is currently being described.
Piezoelectric actuators in the stator assembly are stator piezoelectric actuators (or simply stator actuators) and magnets affixed to stator piezoelectric actuators are stator magnets, and vice versa with regard to the rotor assembly. At the same time, for purposes of this aspect, magnets Date Recue/Date Received 2022-02-28 can also be described as falling into one or both of two distinct types independent of whether they are part of the stator assembly or the rotor assembly. Actuator magnets are magnets which have/are having force imposed upon them by a piezoelectric actuator. Response magnets are magnets which have/are having force imposed upon them via magnetic field interactions with actuator magnets. If only one group of magnets is affixed to piezoelectric actuators, those are the actuator magnets, and the rest of the magnets in the motor are response magnets. If multiple groups of magnets are affixed to piezoelectric actuators, magnets affixed to a piezoelectric actuator which is being energized and causing it to impose force on those magnets are actuator magnets, and magnets which are not so affixed, or which are affixed to a piezoelectric actuator which is not being energized, are response magnets. It is possible for any given magnet to be an actuator magnet or a response magnet or both at any given time depending on the motor controller's configuration and energization of the piezoelectric actuators. A
rotor magnet or a stator magnet may at any time be an actuator magnet, a response magnet, or both.
[00246] By referring to FIGURE 23, the basic nature of the electric motor with positional sensing 10 can be easily understood. Outer rotor housing 11 surrounds bearing 12 which is free to rotate on balls 13, which bear the load between the motor and whatever it is mounted in and whatever it is driving. Inner rotor element 14 has multiple rotor magnets 15 having rotor north poles 15a and rotor south poles 15b. Any suitable magnet may be used for rotor magnets 15, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare-earth magnetic particles.
Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00247] Stator assembly 19 consists of central hub 18, which supports multiple stator piezoelectric actuators 17. Stator piezoelectric actuators 17 have a magnet mount end 17a and a hub end 17b. Stator piezoelectric actuators 17 are connected to a switching power supply (not shown) which can energize the stator piezoelectric actuators at any reasonable driving frequency. When the stator piezoelectric actuators are energized, they expand, using the principle of piezoelectric expansion, also known as the piezoelectric effect, which is well known to persons of ordinary skill in the art. Stator piezoelectric actuators 17 are constructed so that their expansion is along their long axes: in other words, when the stator piezoelectric Date Recue/Date Received 2022-02-28 actuators are energized, the distance between magnet mount end 17b and hub end 17a increases.
[00248] Mounted to magnet mount ends 17b are stator magnets 16, having stator north poles 16a and stator south poles 16b. Any suitable magnet may be used for stator magnets 16, including but not limited to rare-earth magnets, ferromagnets, and/or ceramic magnets containing ferromagnetic and/or rare- earth magnetic particles. Electromagnets may also be used. If electromagnets are used, it is optional, but neither preferred nor required, to allow them to reverse polarity as driven by a solid-state commutator of the type found in traditional brushless electric motors.
[00249] It is strongly preferred that the rotor magnets and the stator magnets have the same poles (north and north or south and south) in opposition at their closest points (as shown) but with proper configuration, it is possible to practice the invention with the rotor magnets and the stator magnets having opposite poles (north and south or south and north) in opposition.
If opposite poles are put into opposition, the motor may require an external initiating force and/or the stator piezoelectric actuators may be required to be energized in a staggered sequence. If reversible electromagnets are used for either the rotor magnets, the stator magnets, or both, the question of initial polarities is unimportant.
[00250] The preferred embodiment pictured in FIGURE 23 shows the invention ready to be practiced. The magnetic forces from the rotor magnets and the stator magnets are at a point of equilibrium where the magnets are in the lowest possible potential energy state with regard to the magnetic repulsion between the rotor magnets and the stator magnets. Inner rotor element 14 will, absent the addition of energy from some exterior source, remain at this point of equilibrium indefinitely.
[00251] To practice the invention, stator piezoelectric actuators 17 are energized. This causes the distance between hub end 17b and magnet mount end 17a to increase, pushing stator magnet 16 closer to rotor magnet 15. This increases the magnetic repulsion between the rotor magnet and the stator magnet, disturbing the equilibrium between them. In the configuration shown, it may be necessary to impart a slight initial rotational force and/or to energize the stator piezoelectric actuators in sequence so as to asymmetrically disturb the equilibrium of magnetic forces and allow rotation to begin.
Date Recue/Date Received 2022-02-28 [00252] Once the equilibrium between the rotor magnets and the stator magnets is disturbed, the system will have more magnetic potential energy than before, which will cause the rotor magnets to exert a force on inner rotor 14. Inner rotor element 14 is free to rotate, so it will rotate in one direction or the other as impelled by the balance of forces. As will be shown in later figures, control of the shape and orientation of the rotor magnets and/or stator magnets will allow for a preferred direction of rotation.
[00253] The switching power supply is controlled by a frequency controller (not shown) which causes it to energize and de-energize stator piezoelectric actuators 17 at a frequency which will continue to convert magnetic potential energy into rotational energy and accelerate inner rotor element 14 in a rotational fashion. It is preferred, but not required, that sensors (not shown) be operably connected to the inner rotor element or otherwise be able to detect its angular velocity, and communicate it to the frequency controller such that the frequency controller can adjust the driving frequency to increase or decrease the force exerted by the stator magnets on the rotor magnets and thus either increase the speed of rotation (under constant load,) increase the applied torque (under increasing load,) or both.
[00254] To obtain the benefits of the positional sensing aspect of the invention, the frequency controller is connected to, or integrated with, a counting device, an induced current sensor, or both.
[00255] If a counting device is used, the frequency controller is connected to or integrated with the counting device (not shown,) which can detect each instance of a current being induced by the rotor magnets rotating past the stator magnets. The counting device could be as simple as a circuit in the frequency controller which can detect back-currents or it can be a more sophisticated separate device as is appropriate to the application in which the electric motor with positional sensing is being used.
[00256] Because the geometry of the rotor magnets and the stator magnets is known, the amount of rotational arc the motor, or any element attached to it, goes through each time the rotor magnets rotate past the stator magnets is also known. For instance, if the rotor magnet/stator magnet pairs each encompass an arc of 10 degrees (or it /18 radians) of the rotation of the motor, each instance of a current induction equals a rotation of 10 degrees (or it /18 radians). To obtain distance moved, the diameter of the circle described by the element Date Recue/Date Received 2022-02-28 whose position is to be measured is multiplied times the number of current inductions and hence the number of fractional rotations. In a device with a positional element located one meter from the center of the rotor, each current induction / movement of the rotor and stator magnets would equate to an angular movement of:
[00257] 2 * n * 1 meter * 10 degrees / 360 degrees = it /16 meters (or ¨19.6cm) (Where 2 * n * r is the formula for the circumference of a circle with [00258] radius r and the circle here has a radius of one meter.) [00259] It is trivial to derive the angular velocity of the positional element once its angular motion is known: the amount of distance traveled in the prior step is simply divided by the time it took for the element to move that distance. If it took 0.1 seconds for the positional element in the prior example to move through an arc of 10 degrees (or it /18 radians) and thus move it /16 meters then the angular velocity would be:
[00260] it /16 meters / 0.1 seconds = it /1.6 meters/second (or ¨1.96 m/s) [00261] It is required that the counting device be able to keep track of the motion of the motor whether or not the piezoelectric actuators are being energized by the switching power supply in some fashion. It is strongly preferred, but not required, that the counting device be able to separately keep track of both the currents which are induced into the motor by the switching power supply (for causing the actuators to move the stator magnets and thus turn the rotor assembly) and currents which are induced into the motor by countermotion of the load or .. other elements attached to the rotor assembly which cause it to rotate by the imposition of an external torque. It is optional, but neither preferred nor required, for the frequency counter to interact with the counting device in such a way as to calibrate the number of current inductions the frequency controller has initiated with the number the counting device detects so that the counting device has a redundant source of information it can use to ensure that current inductions are being counted correctly.
[00262] If an induced current sensor is used, the frequency controller is connected to or integrated with the counting device (not shown,) which can dynamically detect the induced current of a current being induced by the rotor magnets rotating past the stator magnets. The induced current sensor can be as simple as a circuit in the frequency controller which can detect Date Recue/Date Received 2022-02-28 back- currents or it can be a more sophisticated separate device as is appropriate to the application in which the electric motor with positional sensing is being used.
[00263] To use the induced current sensor, the electric motor with positional sensing is operably connected to another motor or other device (hereafter the "calibration load") which can rotate the electric motor with positional sensing without having to apply power to the piezoelectric actuators. It is strongly preferred to use the calibration load to rotate the rotor assembly, but depending on the needs of the particular application, it is optional to use the calibration load to rotate the stator assembly. Whichever of the rotor/stator assemblies is being rotated, it is required that the other either be held static or that its motion be somehow separately measured to allow for full calibration. The former is strongly preferred.
[00264] Once the calibration load is connected (for illustration the following will assume that the stator assembly and the rest of the motor as a whole is being held static and the rotor assembly is being rotated by the calibration load) it is used to accelerate the rotor assembly at a known rate until it is spinning at a known and fixed angular velocity. On a first calibration pass, the induced current sensor is used to dynamically track the current induced in the electric motor with positional sensing by the motion of the rotor magnets past the stator magnets. It is strongly preferred that the motor be rotated for several revolutions to obtain a good set of average values. Because no two of the rotor magnets and/or stator magnets will have exactly the same magnetic strength (this can be varied by design or the inevitable inconsistencies in manufacture can be used) the induced current sensor will track the current being induced as a variable periodic wave (the "base wave.") [00265] As the base wave will be unique, at sufficient precision of measurement, at each point in the rotation of the rotor assembly to any reasonable level, it can be used to map the magnetic field of the rotor magnets relative to the stator magnets. This data is stored for a later step in the process.
[00266] It is optional but strongly preferred to then repeat the calibration steps above with the piezoelectric actuators energized by the stepping power supply, creating measurements of another variable periodic wave, the "energized" wave. This can be done at any reasonable level of energization, but it is required that the calibration load have sufficient power to rotate the motor against the resulting (potentially) increased magnetic Date Recue/Date Received 2022-02-28 attraction/repulsion, especially if the motor starts out from a dead stop. As will be apparent to persons of ordinary skill in the art, the "back-current" which will be measured if the piezoelectric actuators are energized by the power supply will be the sum of the current being induced by the power supply and the current being induced by the calibration load, which will not be in phase, and the measurements must be used accordingly when using the energized wave in later steps.
[00267] It is optional to first spin up the motor with the frequency controller and then apply the calibration load with (and against) up to full energization of the piezoelectric actuators. This will create yet another variable periodic wave or waves (the base wave and all of the energized waves collectively the "waves.") All of the waves should be quite similar to the base wave when adjusted for the current being supplied by the power supply, but will contain additional minute variations. This data is also stored for a later step in the process. It is optional, but not preferred, to use multiple levels of energization, or even to only used an energized level and not measure the base wave.
[00268] Once the waves are measured and the data stored, it is used to construct a map of the magnetic fields of the rotor and stator magnets (the "field map.") To practice the invention using the induced current sensor, the motor is put into operation, and the point on the map of the magnetic fields where the rotor assembly is located is determined at a time or times when the position of the rotor is to be determined. This is known as "resolving" the motor or .. resolving the rotor position.
[00269] It is optional, but strongly preferred, to use some exterior sensor to measure any material external electromagnetic fields, variations in temperature, et cetera, which might affect the nature of the waves when using the positional sensing capability of the motor. While the relative positions of the rotor magnets and stator magnets should produce consistently shaped waves, the actual amplitude and frequency of the waves, and thus the precision of the positional sensing, will vary according to these and other factors which will be apparent to those of ordinary skill in the art.
[00270] Although the preferred embodiment is described as an electric motor with positional sensing, which is designed to convert electrical potential from a switching power supply into rotational energy, it will be apparent to persons of ordinary skill in the art that since Date Recue/Date Received 2022-02-28 the piezoelectric effect works both ways ¨ electrical potential can be turned into mechanical force, and mechanical force can be turned into electrical potential ¨ that the preferred embodiment can also serve as a generator of electrical power if an external load forces the inner rotor element to rotate against the magnetic force attempting to hold it in equilibrium.
.. Similarly, the preferred embodiment can also be used as a drive motor which also provides regenerative braking by switching from power in (during drive mode) to power out (during regenerative braking mode.) All of the alternate configurations/embodiments/methods of practice described in this paragraph are applicable to all of the embodiments of the invention disclosed in this application.
[00271] Additional embodiments of the electric motor with positional sensing will now be described. All of the additional embodiments are alternate configurations of the physical motor itself: the principles by which each embodiment can be used as an electric motor with positional sensing is identical to that described above.
[00272] FIGURE 24 shows a first alternate embodiment of the electric motor with positional sensing. The first alternate embodiment of the electric motor with positional sensing works in the same general fashion as the embodiment of FIGURE 23, except where noted otherwise. It likewise would incorporate a switching power supply, frequency controller, and could incorporate sensors, et cetera.
[00273] Electric motor with positional sensing 20 incorporates rotor piezoelectric actuators 27b, analogous to stator piezoelectric actuators 17 in FIGURE 23.
[00274] Electric motor with positional sensing 20 also incorporates stator piezoelectric actuators 27a. It is neither preferred nor required for either configuration to be applied with a single (inner and outer) group of piezoelectric actuators or a double (inner and outer) group of piezoelectric actuators: the two configurations are shown for clarity of disclosure.
[00275] When either stator piezoelectric actuators 27a or rotor piezoelectric actuators 27b are energized, rotor magnets 25 are pushed toward stator magnets 26, and as in FIGURE
23, magnetic repulsion is increased, incurring a force against the rotor piezoelectric actuators.
As the rotor piezoelectric actuators are affixed to outer casing 21, which is free to rotate relative to hub 29 on bearing 52 (not identified, see FIGURE 27) which includes race 22 containing Date Recue/Date Received 2022-02-28 balls 23, balls 23 bearing the load and allowing rotation of rotary center bearing element 24 relative to fixed center bearing element 28.
[00276] Depending on the desired method of operation, the stator piezoelectric actuators can be activated in concert with the rotor piezoelectric actuators, or only one or the other group of piezoelectric actuators can be active at any given time. Activating both at once can be used to increase torque/rotational velocity, whereas activating only one or the other can be used for lower output modes. Alternatively, one group of piezoelectric actuators can be wired to deliver input power (motor driving) and the other group wired to receive output power (generation/regenerative braking.) The groups of piezoelectric actuators can also be wired such that some of the actuators in each group are preferentially used to deliver input power and some are preferentially used to receive output power. Finally, all or fewer than all of the piezoelectric actuators in a particular group can be active at any given time to deliver any particular desired amount of input power or receive any particular desired amount of output power, allowing an additional means of controlling power flow and/or reducing electrical fatigue on the individual components as they are cycled in and out of service.
[00277] FIGURE 25 shows the first alternate embodiment in cutaway form.
Electric motor with positional sensing 20, having the same components as in FIGURE 24, is surrounded by backing plate 33 and housing 31, while hollow shaft 32, which is operably affixed to hub 29 (see FIGURE 24) and/or rotary center bearing element 24, allows either delivery of mechanical rotational energy (motor mode) or input of mechanical rotational energy (generation/regenerative braking mode.) [00278] FIGURE 26 shows a pair of opposing piezoelectric actuators and their corresponding magnets in detail. Stator piezoelectric actuator 27b is affixed to stator magnet which has stator north pole 25a and stator south pole 25b. Rotor piezoelectric actuator 27a 25 is affixed to rotor magnet 26 which has rotor north pole 26a and rotor south pole 27a. It is preferred, but not required, that the rotor magnets and the stator magnets be asymmetrical to each other (that is, the rotor magnets are not symmetrical with the stator magnets, shown here as their being different sizes) to make it easier to overcome the tendency of the system to "lock"
into a position of minimized magnetic potential energy. Since the magnets are not symmetrical, when they are moved in relation to each other the corresponding magnetic fields will tend to push more in one direction than the other, overcoming such locking symmetry.
Date Recue/Date Received 2022-02-28 [00279] FIGURE 27 shows a more complete assembly of the first alternate embodiment of the invention for clarity of disclosure. Axial bolt 51 holds the assembly together and keeps the rotary elements on-center. Bearing 52 incorporates rotary center bearing element 24, race 22, balls 23, and fixed center bearing element 28. (See FIGURE 24 for more detail.) [00280] FIGURE 28 shows a second alternate embodiment of the electric motor with positional sensing with a more complex configuration of rotor magnets and stator magnets.
This configuration, while not required, is somewhat preferred as it provides multiple benefits to the practice of the invention at the price of higher complexity and cost of manufacture.
[00281] Electric motor with positional sensing 60 comprises rotor assembly 614 and stator assembly 618. Rotably affixing the rotor assembly to the stator assembly is bearing 652 which rotates around central point 611. Mechanically affixed to bearing 652 are one or more stator piezoelectric elements. Shown is a configuration with six such stator piezoelectric elements including stator piezoelectric element 619. Mechanically affixed to the stator piezoelectric elements are stator magnet elements such as stator magnet element 640. The stator magnet elements comprise one or more magnets having a north pole and a south pole, such as stator magnet 617 having stator magnet north pole 617a and stator magnet south pole 617b.
There is a gap between the stator magnet elements and one or more rotor magnet elements.
Shown is a configuration with six such rotor magnet elements including rotor magnet element 642. Each rotor magnet element includes one or more rotor magnets such as rotor magnet 616, which has rotor magnet north pole 616a and rotor magnet south pole 616b.
[00282] To practice this aspect of the invention, as with prior described embodiments, one or more of the stator piezoelectric actuators, such as stator piezoelectric actuator 619, is energized by a switching power supply (NOT SHOWN) controlled by a frequency controller (NOT SHOWN) such that when, for example, stator piezoelectric actuator 619 is energized, it expands along axis of expansion 619a, causing the corresponding stator magnet element to get closer to one or more rotor magnet elements. This produces a change in the orientation of the magnetic fields of the stator and rotor magnetic elements, causing the corresponding stator magnetic element to exert a force on the rotor magnetic element which in turn causes the rotor magnet element to exert a force on the housing 612, causing it, along with the entire rotor assembly 614 to rotate around central point 611 on bearing 652 relative to stator assembly 618.
Date Recue/Date Received 2022-02-28 This rotational force is transmitted to an external load via hollow shaft 632 (NOT SHOWN, see FIGURE 29.) [00283] It is not required that each rotor magnet element be exactly geometrically opposed to a stator magnet element at any particular time during operation or non-operation and in fact it is likely that the equilibrium during non-operation will result in some degree of offset. It is strongly preferred that there be a rotor magnet element for each stator magnet element, and vice versa. It is required that there be a gap between the rotor magnet elements and the stator magnet elements sufficient to allow the rotor magnet elements to move freely without contacting the stator magnet elements under any reasonable amount of bearing load, rotary speed, or transient vibratory load.
[00284] Although the configuration of magnets shown will be inherently stable due to magnetic attraction between the individual magnets, it is preferred that the magnets in each rotor magnet element and stator magnet element be epoxied or otherwise physically affixed to each other to maintain the desired alignment and prevent shifting under load or due to vibration .. or other transient phenomena.
[00285] It is strongly preferred, but not required, to use an overlapping configuration of magnets as shown in the rotor magnet elements and the stator magnet elements as this will minimize asymmetries in the overall magnetic field structure in the brushless magnetic motor.
FIGURE 7 shows a more complete assembly of the second alternate embodiment of the invention for clarity of disclosure along with the addition of an optional set of stator piezoelectric actuators as in FIGURE 24. (See FIGURE 28 for more detail.) Axial bolt 651 holds the assembly together and keeps the elements on-center. Capacitor array bolts 680 affix capacitor array 656 to base element 682 by means of threaded receivers 681.
Although shown as traditional capacitive plates, any desired means of capacitive induction of current, such as vacuum-tube capacitors, can be used.
[00286] For purposes of this description, it is assumed that base element 682 is secured to something which is designated as static and therefore base element 682 forms part of a stator assembly. For example, if motor 60 were to be used to drive the wheel of an electric vehicle, base element 682 would ultimately be statically affixed to the chassis of the vehicle, whereas housing 612 would ultimately be statically affixed to the wheel of the vehicle.
Date Recue/Date Received 2022-02-28 [00287] Capacitor array 680, which does not rotate relative to the stator assembly, includes capacitor plates such as capacitor plate 658, each capacitor plate separated by a gap such as capacitor gaps 657a and 657b. Capacitor array energizes rotor piezoelectric array 621, which includes one or more rotor piezoelectric actuators such as rotor piezoelectric actuator 621. The rotor piezoelectric actuators are mechanically affixed to one or more (optional) rotor magnet brackets 678, each rotor magnet bracket having a rotor circumferential surface 662, and (optional) rotor vertical guides 661a and 661b, with all of the rotor magnet brackets forming rotor magnet bracket assembly 660. Mechanically affixed to the rotor piezoelectric actuators, either directly or via the (optional) rotor magnet brackets, are one or more rotor magnet elements such as rotor magnet element 642, each rotor magnet element comprising one or more rotor magnets such as rotor magnet 616, with all of the rotor magnet elements forming rotor magnet assembly 672.
[00288] When energized, the rotor piezoelectric actuators expand toward the center of motor 60 (since they cannot expand against the fixed position of the rest of the rotor assembly including ultimately housing 612) pushing the rotor magnet elements toward the stator magnet elements (see below) and imparting a magnetic force as explained in previous descriptions (see FIGURES 23, 24, and 28.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632.
The rotor piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The rotor piezoelectric actuators can be energized without energizing the stator piezoelectric actuators (see below) or in concert with them.
[00289] Rotor magnet assembly 672 radially surrounds stator magnet assembly 670, the rotor magnet assembly separated from the stator magnet assembly by a gap (NOT
SHOWN, see FIGURE 31.) Stator magnet assembly 670 comprises one or more stator magnet elements such as stator magnet element 640, each stator magnet element comprising one or more stator magnets such as stator magnet 617. Stator magnet elements are mechanically affixed to stator piezoelectric assembly 669, which includes one or more stator piezoelectric actuators such as stator piezoelectric actuator 619, either directly or by means of (optional) stator magnet bracket assembly 655. (Optional) stator magnet bracket assembly 655 comprises one or more stator magnet brackets such as stator magnet bracket 676, each stator magnet bracket including a stator circumferential surface such as stator circumferential surface 654 and (optional) stator vertical guides 653a and 653b.
Date Recue/Date Received 2022-02-28 [00290] When energized, the stator piezoelectric actuators expand toward the outer circumference of motor 60 (since they cannot expand toward the fixed position of the rest of the stator assembly) pushing the stator magnet elements toward the rotor magnet elements and imparting a magnetic force as explained in previous descriptions (see FIGURES
23, 24, and 28.) This ultimately causes the rotor assembly, including housing 612, to rotate, allowing for rotary force to be exerted through hollow shaft 632. The stator piezoelectric actuators can be energized one at a time, all together, or in sequence, as is desired and appropriate for the load and conditions. The stator piezoelectric actuators can be energized without energizing the rotor piezoelectric actuators or in concert with them.
[00291] FIGURE 30 shows the configuration of FIGURE 29 in an alternate phase of assembly for clarity of disclosure. Housing 612 is ready to be placed over the rest of the motor assembly, with capacitor array 656 ready to be secured to base element 682 with capacitor array bolts 680. The rotor and stator elements are assembled, for example rotor piezoelectric actuator affixed to rotor circumferential surface 662 and stator piezoelectric actuator affixed to stator circumferential surface 654, and both ready to be inserted into their respective assemblies.
[00292] FIGURE 31 shows the configuration of FIGURE 29 in a cutaway view for clarity of disclosure. Housing 612 is axially secured by axial bolt 651 but is free to rotate relative to base element 682 as they are mechanically connected only by bearings 652 and 683.
Rotor magnet element 642 is separated from stator magnet element 640 by gap 690. The size of gap 690 can be changed by energizing stator piezoelectric actuator 619 and/or rotor piezoelectric actuator 621. As the piezoelectric actuators change the size of gap 690, the relative orientation of the magnetic fields of the rotor magnet elements and the stator magnet elements will change. This will cause magnetic force to be exerted between magnet elements, .. but as only the rotor magnet elements (ultimately connected to housing 612) can move, the force will cause housing 612 to move, allowing rotary motion to be imparted to hollow shaft 632 and thus to an axle, a wheel, or any other rotary member or rotary load desired.
[00293] FIGURE 32 shows a third alternate embodiment of the invention.
In this embodiment, rather than a plurality of distinctive magnets, the rotor magnets comprise a single piece of rotor magnetic material, which is structured to have a plurality of magnetic regions, each magnetic region having a north pole and a south pole. Similarly, there are two individual Date Recue/Date Received 2022-02-28 pieces of stator magnetic material having a plurality of magnetic regions.
Each piece of stator magnetic material is attached to one end of a single piezoelectric actuator.
[00294] Electric motor with positional sensing 80 comprises rotor assembly 82, stator magnet assemblies 84 and 87, and piezoelectric actuator 810 which is operably affixed to PCB
92 (NOT SHOWN: See FIGURE 33.) Rotor assembly 82, which is free to rotate relative to all stator assembly components and is attached to whatever rotational load (NOT
SHOWN) it is desired to accelerate with the motor, is comprised of magnetic material (or can have an inner section of magnetic material surrounded by non-magnetic material as desired) which has magnetic regions, each magnetic region having a north pole and a south pole such as rotor north poles 82a and 82b and rotor south poles 83a and 83b. Opposite the rotor assembly's magnetic material, separated by a gap (See FIGURE 33,) are stator magnet assemblies 84 and 87. It is possible to construct this embodiment of the invention with a single stator magnet assembly, but it is strongly preferred to use two symmetrical stator magnet assemblies as shown for purposes of balance and to maximize the piezoelectric actuator's efficiency. First stator magnet assembly 84, similarly to rotor section 82, is composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and rotor south poles 86a and 86b. Second stator magnet assembly 87, is likewise composed in whole or in part of magnetic material, which has multiple magnetic regions, each magnetic region having a north pole such as stator north poles 85a and 85b and stator south poles 86a and 86b.
[00295] FIGURE 33 shows a cutaway view of the third alternate embodiment of this aspect of the disclosure for additional clarity. Electric motor with positional sensing 80 has gap 91, which separates the various motor assemblies (see FIGURE 32) and allows the motor to also serve as a no-contact magnetic bearing so long as the planar load does not materially affect the gap as maintained by the magnetic fields of the rotor magnet assembly and the stator magnet assemblies. This is an additional advantage of several of the embodiments and configurations of the invention disclosed herein. PCB 92 is a printed circuit board which is both mechanically and electrically affixed to piezoelectric actuator 810 and provides it with electrical potential from a switching power supply (NOT SHOWN.) [00296] If necessary, fluid can be forcibly circulated around the assemblies or even through the gap to cool the motor, but as many piezoelectric devices actually work better when Date Recue/Date Received 2022-02-28 they reach a relatively high operating temperature, the need for cooling will be minimal in many applications. This is another advantage of the invention. It is required that for all embodiments and configurations of the invention, that operating temperatures be kept low enough to avoid demagnetization of any permanent magnets which are used. This will vary as various kinds of magnetic material have different demagnetization thresholds.
(For example, some ferrite magnets can tolerate temperatures up to 250 C, whereas some rare-earth magnets can only tolerate temperatures up to 100 C.) [00297] To practice an embodiment of this aspect of the invention, an electrical potential is put across piezoelectric actuator 810, which is electrically connected to PCB 92. This causes piezoelectric actuator 810 to expand along its long axis, changing the relative position of the stator magnet assemblies and the rotor assembly. This in turn causes electromagnetic force to be exerted on the rotor assembly, which will rotate to a position which will minimize the magnetic potential energy between the rotor assembly and the stator assemblies. The electrical potential across piezoelectric actuator 810, is then removed and/or reversed, causing it to contract along its long axis, again changing the relative position of the various magnet assemblies, and imparting more rotational energy to the rotor assembly. A
switching power supply (NOT SHOWN) continuously cycles the electrical potential across the piezoelectric actuator to produce the desired rotational energy as in earlier described embodiments.
[00298] It is optional, but neither preferred nor required, for either the rotor assembly or the stator assembly, or both, to comprise multiple magnets as in earlier described configurations. (See FIGURE 23, FIGURE 24, and/or FIGURE 28.) So long as the rotor assembly and the stator assembly are configured as shown, the configuration of this third alternate embodiment incorporating a single piezoelectric actuator will function and provide the benefits of the invention.
[00299] Alternate configurations of this aspect of the disclosure, which can be applied to any of the described embodiments, will now be disclosed.
[00300] In a first alternate configuration of this aspect (NOT SHOWN) some or all of the rotor magnets, or some or all of the stator magnets, of either the preferred embodiment or the first alternate embodiment are replaced with electromagnets.
Date Recue/Date Received 2022-02-28 [00301] In a second alternate configuration of this aspect (NOT SHOWN) one or more elastic members is fitted into the motor assembly such that the piezoelectric actuators are working against the elastic members when they are energized, compressing them and creating elastic potential energy, so that when the piezoelectric actuator(s) is/are de-energized, the magnet(s) affixed to the piezoelectric actuator(s) return to their prior position more quickly and without the need to impose a reverse polarity potential across the piezoelectric actuator when the elastic potential energy provides impetus to the piezoelectric actuators.
[00302] In a third alternate configuration of this aspect (NOT SHOWN) the features of the first and second configurations are combined.
[00303] It will be apparent to those of ordinary skill in the art that while this aspect and its preferred embodiments are described in terms of rotary motors, the principles taught by the invention can be used to create linear motors, such as reciprocating motors, by using the basic principle of piezoelectric motivation of opposing magnetic elements to create a linear force instead of a centripetal force. Thus, the claims below include both rotary configurations and linear configurations where and as appropriate.
[00304] While various embodiments and configurations of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. Thus, the breadth and scope of the present invention should not be limited by any of the above exemplary embodiments.
[00305] This application ¨ taken as a whole with the abstract, specification, and drawings being combined ¨ provides sufficient information for a person having ordinary skill in the art to practice the invention as disclosed herein. Any measures necessary to practice this invention are well within the skill of a person having ordinary skill in this art after that person has made a careful study of this disclosure.
[00306] Because of this disclosure and solely because of this disclosure, modification of this device and method can become clear to a person having ordinary skill in this particular art.
Such modifications are clearly covered by this disclosure.
[00307] While the present disclosure describes various embodiments for illustrative purposes, such description is not intended to be limited to such embodiments.
On the contrary, Date Recue/Date Received 2022-02-28 the applicant's teachings described and illustrated herein encompass various alternatives, modifications, and equivalents, without departing from the embodiments, the general scope of which is defined in the appended claims. Except to the extent necessary or inherent in the processes themselves, no particular order to steps or stages of methods or processes described in this disclosure is intended or implied. In many cases the order of process steps may be varied without changing the purpose, effect, or import of the methods described.
[00308] Information as herein shown and described in detail is fully capable of attaining the above-described object of the present disclosure, the presently preferred embodiment of the present disclosure, and is, thus, representative of the subject matter which is broadly contemplated by the present disclosure. The scope of the present disclosure fully encompasses other embodiments which may become apparent to those skilled in the art, and is to be limited, accordingly, by nothing other than the appended claims, wherein any reference to an element being made in the singular is not intended to mean "one and only one"
unless explicitly so stated, but rather "one or more." All structural and functional equivalents to the elements of the above-described preferred embodiment and additional embodiments as regarded by those of ordinary skill in the art are intended to be encompassed by the present claims. Moreover, no requirement exists for a system or method to address each and every problem sought to be resolved by the present disclosure, for such to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. However, that various changes and modifications in form, material, work-piece, and fabrication material detail may be made, without departing from the spirit and scope of the present disclosure, as set forth in the appended claims, as may be apparent to those of ordinary skill in the art, are also encompassed by the disclosure.
Date Recue/Date Received 2022-02-28
Claims (70)
1. A magnetic bearing comprising:
a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply;
b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes; and d) a bearing assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that a magnetic repulsion force between the actuator magnets and the response magnets acts to maintain the size of the variable gap against a load.
a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply;
b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes; and d) a bearing assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that a magnetic repulsion force between the actuator magnets and the response magnets acts to maintain the size of the variable gap against a load.
2. The magnetic bearing as claimed in Claim 1, wherein there is one and only one group of piezoelectric actuators, and the one and only one group of piezoelectric actuators comprises one and only one piezoelectric actuator, and there is one and only one group of actuator magnets, and the one and only one group of actuator magnets comprises two actuator magnets.
3. The magnetic bearing as claimed in Claim 1, wherein the group of response magnets comprises a single piece of magnetic material, the single piece of magnetic material having a plurality of magnetic regions, each magnetic region having a local north pole and a local south pole.
4. The magnetic bearing as claimed in Claim 1, further comprising:
e) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
e) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
5. The magnetic bearing as claimed in Claim 1, wherein there are two groups of piezoelectric actuators, further comprising:
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators fonning a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators fonning a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
6. The magnetic bearing as claimed in Claim 5, further comprising:
g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
7. The magnetic bearing as claimed in Claim 1, wherein each group of actuator magnets has two ends, and wherein the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and wherein each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
8. The magnetic bearing as claimed in Claim 4, wherein each group of actuator magnets has two ends, and wherein the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and wherein each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
9. The magnetic bearing as claimed in Claim 1, further comprising:
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
10. The magnetic bearing as claimed in Claim 2, further comprising:
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
11. The magnetic bearing as claimed in Claim 4, further comprising:
f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
12. The magnetic bearing as claimed in Claim 7, further comprising:
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
13. A magnetic bearing comprising:
a) at least one group of static piezoelectric actuators, the at least one group of static piezoelectric actuators comprising at least one static piezoelectric actuator, all of the static piezoelectric actuators electrically connected to a power supply;
b) a group of static magnets, the group of static magnets comprising at least one static magnet, each of the at least one static piezoelectric actuators mechanically affixed to the group of static magnets;
c) at least one group of mobile piezoelectric actuators, the at least one group of mobile piezoelectric actuators comprising at least one mobile piezoelectric actuator, all of the mobile piezoelectric actuators electrically connected to the power supply;
d) a group of mobile magnets, the group of mobile magnets comprising at least one mobile magnet, each of the at least one mobile piezoelectric actuators mechanically affixed to the group of mobile magnets; and e) a motor assembly having a mobile assembly and a static assembly, the mobile assembly mechanically affixed to the group of mobile piezoelectric actuators, the static assembly mechanically affixed to the group of static piezoelectric actuators, such that there is a variable gap having a size between the group of mobile magnets and the group of static magnets and when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly.
a) at least one group of static piezoelectric actuators, the at least one group of static piezoelectric actuators comprising at least one static piezoelectric actuator, all of the static piezoelectric actuators electrically connected to a power supply;
b) a group of static magnets, the group of static magnets comprising at least one static magnet, each of the at least one static piezoelectric actuators mechanically affixed to the group of static magnets;
c) at least one group of mobile piezoelectric actuators, the at least one group of mobile piezoelectric actuators comprising at least one mobile piezoelectric actuator, all of the mobile piezoelectric actuators electrically connected to the power supply;
d) a group of mobile magnets, the group of mobile magnets comprising at least one mobile magnet, each of the at least one mobile piezoelectric actuators mechanically affixed to the group of mobile magnets; and e) a motor assembly having a mobile assembly and a static assembly, the mobile assembly mechanically affixed to the group of mobile piezoelectric actuators, the static assembly mechanically affixed to the group of static piezoelectric actuators, such that there is a variable gap having a size between the group of mobile magnets and the group of static magnets and when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly.
14. The magnetic bearing as claimed in Claim 13, further comprising:
f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the magnetic bearing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
15. The magnetic bearing as claimed in Claim 13, wherein each group of static magnets and/or each group of mobile magnets is a group of magnets containing at least two magnets, and wherein each group of magnets has two ends, and wherein the magnets in each group of magnets overlap each other to produce a combined magnetic field, and wherein each of the magnets in a group of magnets has a north pole and a south pole, and the south pole of any particular magnet is either physically proximate to one of the two ends, or to the north pole of another magnet in the same group of magnets, and the north pole of any particular magnet is either physically proximate to one of the two ends, or to the south pole of another magnet in the same group of magnets.
16. The magnetic bearing as claimed in Claim 1, wherein the piezoelectric actuators are electrically connected to the power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by the power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
17. The magnetic bearing as claimed in Claim 1, further comprising:
e) a frequency controller, the frequency controller controlling the power supply such that the frequency controller can cause the power supply to apply a positive voltage or a negative voltage to one or more of the piezoelectric actuators.
e) a frequency controller, the frequency controller controlling the power supply such that the frequency controller can cause the power supply to apply a positive voltage or a negative voltage to one or more of the piezoelectric actuators.
18. The magnetic bearing as claimed in Claim 17, further comprising:
f) a heat sensor, the heat sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a detected temperature.
f) a heat sensor, the heat sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a detected temperature.
19. The magnetic bearing as claimed in Claim 17, further comprising:
f) a gap sensor, the gap sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a change in the size of the variable gap.
f) a gap sensor, the gap sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a change in the size of the variable gap.
20. The magnetic bearing as claimed in Claim 16, further comprising:
f) an acceleration sensor, the acceleration sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a detected acceleration.
f) an acceleration sensor, the acceleration sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a detected acceleration.
21. The magnetic bearing as claimed in Claim 20, further comprising:
f) a gap sensor, the gap sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a change in the size of the variable gap.
f) a gap sensor, the gap sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a change in the size of the variable gap.
22. The magnetic bearing as claimed in Claim 21, further comprising:
f) a heat sensor, the heat sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a detected temperature.
f) a heat sensor, the heat sensor linked to the frequency controller controlling the power supply such that the frequency controller can cause the power supply to adjust the positive voltage or the negative voltage of the piezoelectric actuators in response to a detected temperature.
23. An electric stepper motor comprising:
a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a switching power supply;
b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the switching power supply, the size of the variable gap changes;
d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly;
and e) a frequency controller, electrically connected to the switching power supply, which causes the switching power supply to energize, and then de-energize, some or all of the piezoelectric actuators a fixed number of times such that the mobile assembly moves a target fixed distance.
a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a switching power supply;
b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the switching power supply, the size of the variable gap changes;
d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly;
and e) a frequency controller, electrically connected to the switching power supply, which causes the switching power supply to energize, and then de-energize, some or all of the piezoelectric actuators a fixed number of times such that the mobile assembly moves a target fixed distance.
24. The electric stepper motor as claimed in Claim 23, wherein there is one and only one group of piezoelectric actuators, and the one and only one group of piezoelectric actuators comprises one and only one piezoelectric actuator, and there is one and only one group of actuator magnets, and the one and only one group of actuator magnets comprises two actuator magnets.
25. The electric stepper motor as claimed in either one of Claim 23 or Claim 24, wherein the group of response magnets comprises a single piece of magnetic material, the single piece of magnetic material having a plurality of magnetic regions, each magnetic region having a local north pole and a local south pole.
26. The electric stepper motor as claimed in Claim 23, further comprising:
f) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
f) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
27. The electric stepper motor as claimed in Claim 23, wherein there are two groups of piezoelectric actuators, further comprising:
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators folming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators folming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
28. The electric stepper motor as claimed in Claim 27, further comprising:
g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they foim a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they foim a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
29. The electric stepper motor as claimed in Claim 26, wherein there are two groups of piezoelectric actuators, further comprising:
f) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and g) a second group of piezoelectric actuators foiming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
f) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and g) a second group of piezoelectric actuators foiming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
30. The electric stepper motor as claimed in Claim 26, wherein each group of actuator magnets has two ends, and wherein the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and wherein each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
31. The electric stepper motor as claimed in Claim 30, wherein the actuator magnets in each group of actuator magnets are secured by an adhesive, the adhesive securing the actuator magnets in a fixed orientation.
32. The electric stepper motor as claimed in Claim 23, further comprising:
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
33. The electric stepper motor as claimed in Claim 24, further comprising:
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
34. The electric stepper motor as claimed in Claim 26, further comprising:
f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
35. An electric stepper motor comprising:
a) at least one group of static piezoelectric actuators, the at least one group of static piezoelectric actuators comprising at least one static piezoelectric actuator, all of the static piezoelectric actuators electrically connected to a switching power supply;
b) a group of static magnets, the group of static magnets comprising at least one static magnet, each of the at least one static piezoelectric actuators mechanically affixed to the group of static magnets;
c) at least one group of mobile piezoelectric actuators, the at least one group of mobile piezoelectric actuators comprising at least one mobile piezoelectric actuator, all of the mobile piezoelectric actuators electrically connected to the switching power supply;
d) a group of mobile magnets, the group of mobile magnets comprising at least one mobile magnet, each of the at least one mobile piezoelectric actuators mechanically affixed to the group of mobile magnets;
e) a motor assembly having a mobile assembly and a static assembly, the mobile assembly mechanically affixed to the group of mobile piezoelectric actuators, the static assembly mechanically affixed to the group of static piezoelectric actuators, such that there is a variable gap having a size between the group of mobile magnets and the group of static magnets and when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and f) a frequency controller, electrically connected to the switching power supply, which causes the switching power supply to energize, and then de-energize, some or all of the static piezoelectric actuators and/or some or all of the mobile piezoelectric actuators a fixed number of times such that the mobile assembly moves a target fixed distance.
a) at least one group of static piezoelectric actuators, the at least one group of static piezoelectric actuators comprising at least one static piezoelectric actuator, all of the static piezoelectric actuators electrically connected to a switching power supply;
b) a group of static magnets, the group of static magnets comprising at least one static magnet, each of the at least one static piezoelectric actuators mechanically affixed to the group of static magnets;
c) at least one group of mobile piezoelectric actuators, the at least one group of mobile piezoelectric actuators comprising at least one mobile piezoelectric actuator, all of the mobile piezoelectric actuators electrically connected to the switching power supply;
d) a group of mobile magnets, the group of mobile magnets comprising at least one mobile magnet, each of the at least one mobile piezoelectric actuators mechanically affixed to the group of mobile magnets;
e) a motor assembly having a mobile assembly and a static assembly, the mobile assembly mechanically affixed to the group of mobile piezoelectric actuators, the static assembly mechanically affixed to the group of static piezoelectric actuators, such that there is a variable gap having a size between the group of mobile magnets and the group of static magnets and when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly; and f) a frequency controller, electrically connected to the switching power supply, which causes the switching power supply to energize, and then de-energize, some or all of the static piezoelectric actuators and/or some or all of the mobile piezoelectric actuators a fixed number of times such that the mobile assembly moves a target fixed distance.
36. The electric stepper motor as claimed in Claim 35, further comprising:
g) a group of elastic members, the elastic members mechanically affixed to at least one of the static or mobile piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
g) a group of elastic members, the elastic members mechanically affixed to at least one of the static or mobile piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
37. The electric stepper motor as claimed in Claim 35, further comprising:
f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the switching power supply and mechanically affixed to a housing of the electric stepper motor such that when the group of capacitor plates are energized by the switching power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
38. The electric stepper motor as claimed in Claim 35, wherein each group of static magnets and/or each group of mobile magnets is a group of magnets containing at least two magnets, and wherein each group of magnets has two ends, and wherein the magnets in each group of magnets overlap each other to produce a combined magnetic field, and wherein each of the magnets in a group of magnets has a north pole and a south pole, and the south pole of any particular magnet is either physically proximate to one of the two ends, or to the north pole of another magnet in the same group of magnets, and the north pole of any particular magnet is either physically proximate to one of the two ends, or to the south pole of another magnet in the same group of magnets.
39. The electric stepper motor as claimed in Claim 35, wherein the piezoelectric actuators are electrically connected to the switching power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the switching power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by the switching power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
40. The electric stepper motor as claimed in Claim 23, wherein the piezoelectric actuators are electrically connected to the switching power supply with a capacitive connection, such that a first capacitive surface electrically connected to at least one of the piezoelectric actuators forms a first terminal of a capacitor, and a second capacitive surface electrically connected to the switching power supply forms a second terminal of the capacitor, the first and second terminals separated by a gap, such that when the second capacitive surface is energized by the switching power supply, a current is induced in the first capacitive surface, energizing at least one piezoelectric actuator.
41. The electric stepper motor as claimed in Claim 23, further comprising:
f) a rotary position sensor which can detect an absolute rotary position of the mobile assembly.
f) a rotary position sensor which can detect an absolute rotary position of the mobile assembly.
42. The electric stepper motor as claimed in Claim 41, wherein the rotary position sensor is operably attached to the frequency controller such that the frequency controller can use the absolute rotary position of the mobile assembly to determine when to switch the switching power supply on and off such that the mobile assembly moves the target fixed distance.
43. An electric motor with positional sensing comprising:
a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply;
b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes;
d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly;
and e) a counting device, which counts a number of times that one or more of the actuator magnets passes by one or more of the response magnets in turn from a known starting position, such that a relative position of the mobile assembly relative to the known starting position can be determined by using a ratio of an angle swept by a single actuator magnet or a single response magnet to a total diameter of the static assembly, the counting device being able to count the number of times whether the mobile assembly moves relative to the static assembly due to the plurality of piezoelectric actuators being energized by the power supply or due to an external load which imparts an external torque onto one or both of the static assembly or the mobile assembly.
a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply;
b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes;
d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly;
and e) a counting device, which counts a number of times that one or more of the actuator magnets passes by one or more of the response magnets in turn from a known starting position, such that a relative position of the mobile assembly relative to the known starting position can be determined by using a ratio of an angle swept by a single actuator magnet or a single response magnet to a total diameter of the static assembly, the counting device being able to count the number of times whether the mobile assembly moves relative to the static assembly due to the plurality of piezoelectric actuators being energized by the power supply or due to an external load which imparts an external torque onto one or both of the static assembly or the mobile assembly.
44. The electric motor with positional sensing as claimed in Claim 43, wherein the counting device counts the number of times by detecting a back-current when the piezoelectric actuators are not energized by the power supply, the back- current caused by the piezoelectric actuators being compressed as the actuator magnets move relative to the response magnets due to the external torque.
45. The electric motor with positional sensing as claimed in Claim 43, wherein the group of response magnets comprises a single piece of magnetic material, the single piece of magnetic material having a plurality of magnetic regions, each magnetic region having a local north pole and a local south pole.
46. The electric motor with positional sensing as claimed in Claim 43, further comprising:
f) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
f) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
47. The electric motor with positional sensing as claimed in Claim 43, wherein there are two groups of piezoelectric actuators, further comprising:
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators folming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
e) a first group of piezoelectric actuators forming a group of stator piezoelectric actuators, each of the stator piezoelectric actuators mechanically affixed to a stator magnet;
and f) a second group of piezoelectric actuators folming a group of rotor piezoelectric actuators, each of the rotor piezoelectric actuators mechanically affixed to a rotor magnet.
48. The electric motor with positional sensing as claimed in Claim 47, further comprising:
g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
g) a group of actuator capacitor plates, the group of actuator capacitor plates comprising at least one actuator capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
49. The electric motor with positional sensing as claimed in Claim 43, wherein each group of actuator magnets has two ends, and wherein the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and wherein each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
50. The electric motor with positional sensing as claimed in Claim 49, wherein the actuator magnets in each group of actuator magnets are secured by an adhesive, the adhesive securing the actuator magnets in a fixed orientation.
51. The electric motor with positional sensing as claimed in Claim 47, wherein each group of actuator magnets has two ends, and wherein the actuator magnets in each group of actuator magnets overlap each other to produce a combined actuator magnetic field, and wherein each of the actuator magnets in a group of actuator magnets has a north pole and a south pole, and the south pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the north pole of another actuator magnet in the group of actuator magnets, and the north pole of any particular actuator magnet is either physically proximate to one of the two ends, or to the south pole of another actuator magnet in the group of actuator magnets.
52. The electric motor with positional sensing as claimed in Claim 51, wherein the actuator magnets in each group of actuator magnets are secured by an adhesive, the adhesive securing the actuator magnets in a fixed orientation.
53. The electric motor with positional sensing as claimed in Claim 43, further comprising:
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
54. The electric motor with positional sensing as claimed in Claim 44, further comprising:
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
55. The electric motor with positional sensing as claimed in Claim 47, further comprising:
f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
f) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
56. The electric motor with positional sensing as claimed in Claim 50, further comprising:
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
e) a group of elastic members, the elastic members mechanically affixed to at least one piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
57. An electric motor with positional sensing comprising:
a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply;
b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes;
d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly;
and e) an induced-current sensor, which detects a back-current, the back-current being induced in the piezoelectric actuators when due to an external load imparting an external torque onto one or both of the static assembly or the mobile assembly, the mobile assembly moves relative to the static assembly.
a) at least one group of piezoelectric actuators, the at least one group of piezoelectric actuators comprising at least one piezoelectric actuator, all of the piezoelectric actuators electrically connected to a power supply;
b) a group of actuator magnets, the group of actuator magnets comprising at least one actuator magnet, each of the at least one piezoelectric actuators mechanically affixed to the group of actuator magnets;
c) a group of response magnets, the group of response magnets physically opposed to the first plurality of piezoelectric elements separated by a variable gap having a size, such that when one or more of the plurality of piezoelectric actuators are energized by the power supply, the size of the variable gap changes;
d) a motor assembly including a mobile assembly and a static assembly, the mobile assembly mechanically affixed to either the group of actuator magnets or the group of response magnets, the static assembly mechanically affixed to whichever of the group of actuator magnets or the group of response magnets the mobile assembly is not mechanically affixed, such that when the size of the variable gap changes, a magnetic force is exerted on the mobile assembly, causing the mobile assembly to move relative to the static assembly;
and e) an induced-current sensor, which detects a back-current, the back-current being induced in the piezoelectric actuators when due to an external load imparting an external torque onto one or both of the static assembly or the mobile assembly, the mobile assembly moves relative to the static assembly.
58. The electric motor with positional sensing as claimed in Claim 57, further comprising:
f) a calibration memory device, which can store a plurality of calibration back-current values, the calibration back-current values obtained by using the induced-current sensor to measure the back-current at a plurality of times.
f) a calibration memory device, which can store a plurality of calibration back-current values, the calibration back-current values obtained by using the induced-current sensor to measure the back-current at a plurality of times.
59. The electric motor with positional sensing as claimed in Claim 58, further comprising:
g) a calibration load, the calibration load comprising an external driving device which can be removably connected to the electric motor to impart a controllable external torque onto one or the other of the mobile assembly or the static assembly.
g) a calibration load, the calibration load comprising an external driving device which can be removably connected to the electric motor to impart a controllable external torque onto one or the other of the mobile assembly or the static assembly.
60. The electric motor with positional sensing as claimed in Claim 58, wherein the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply.
61. The electric motor with positional sensing as claimed in Claim 59, wherein the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply.
62. The electric motor with positional sensing as claimed in Claim 58, further comprising:
g) a position determining device, the position determining device dynamically receiving a plurality of operating back-current values from the induced-current sensor, the position determining device comparing the plurality of operating back-current values to the plurality of calibration back-current values to determine a relative position of the mobile assembly to the static assembly.
g) a position determining device, the position determining device dynamically receiving a plurality of operating back-current values from the induced-current sensor, the position determining device comparing the plurality of operating back-current values to the plurality of calibration back-current values to determine a relative position of the mobile assembly to the static assembly.
63. The electric motor with positional sensing as claimed in Claim 59, further comprising:
h) a position determining device, the position determining device dynamically receiving a plurality of operating back-current values from the induced-current sensor, the position determining device comparing the plurality of operating back-current values to the plurality of calibration back-current values to determine a relative position of the mobile assembly to the static assembly.
h) a position determining device, the position determining device dynamically receiving a plurality of operating back-current values from the induced-current sensor, the position determining device comparing the plurality of operating back-current values to the plurality of calibration back-current values to determine a relative position of the mobile assembly to the static assembly.
64. The electric motor with positional sensing as claimed in Claim 62, wherein the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply, and the position determining device compares the first plurality of calibration back-current values and the second plurality of calibration values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
65. The electric motor with positional sensing as claimed in Claim 63, wherein the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply, and the position determining device compares the first plurality of calibration back-current values and the second plurality of calibration values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
66. The electric motor with positional sensing as claimed in either one of Claim 62 or Claim 63, wherein the calibration memory device stores a first plurality of calibration back-current values measured when the piezoelectric actuators are not energized by the power supply, and a second plurality of calibration back-current values measured when the piezoelectric actuators are energized by the power supply, and the first plurality of calibration back-current values and the second plurality of calibration back-current values are combined into a plurality of average calibration back-current values, and the position determining device compares the plurality of average calibration back-current values to the plurality of operating back-current values to determine a relative position of the mobile assembly to the static assembly.
67. The electric motor with positional sensing as claimed in Claim 57, further comprising:
a) a group of elastic members, the elastic members mechanically affixed to at least one of the static or mobile piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
a) a group of elastic members, the elastic members mechanically affixed to at least one of the static or mobile piezoelectric actuator such that when the piezoelectric actuator is energized, the elastic member will acquire an elastic potential energy, and when the piezoelectric actuator is de-energized, the elastic potential energy will be converted into an elastic force which will push against the piezoelectric actuator.
68. The electric motor with positional sensing as claimed in Claim 57, further comprising:
f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
f) a group of energizer capacitor plates, the group of energizer capacitor plates comprising at least one energizer capacitor plate, the group of actuator capacitor plates connected to the power supply and mechanically affixed to a housing of the electric motor with positional sensing such that when the group of capacitor plates are energized by the power supply, they form a capacitor circuit with one or more of the piezoelectric actuators, causing a current to be induced in the piezoelectric actuators in the capacitor circuit.
69. The electric motor with positional sensing as claimed in Claim 57, wherein each group of static magnets and/or each group of mobile magnets is a group of magnets containing at least two magnets, and wherein each group of magnets has two ends, and wherein the magnets in each group of magnets overlap each other to produce a combined magnetic field, and wherein each of the magnets in a group of magnets has a north pole and a south pole, and the south pole of any particular magnet is either physically proximate to one of the two ends, or to the north pole of another magnet in the same group of magnets, and the north pole of any particular magnet is either physically proximate to one of the two ends, or to the south pole of another magnet in the same group of magnets.
70. The electric motor with positional sensing as claimed in either one of Claim 43 or Claim 57, wherein the piezoelectric actuators are electrically connected to the power supply with a capacitive connection, such that at least one of the piezoelectric actuators form a first terminal of a capacitor, and a capacitive surface electrically connected to the power supply forms a second terminal of the capacitor, the capacitive surface separated from at least one piezoelectric actuator by a gap, such that when the second capacitive surface is energized by the power supply, a current is induced in at least one piezoelectric actuator, energizing at least one piezoelectric actuator.
Applications Claiming Priority (8)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
WOPCT/US2021/042859 | 2021-07-22 | ||
PCT/US2021/042859 WO2022055620A1 (en) | 2020-07-28 | 2021-07-22 | Brushless electric motor |
US17/497,033 | 2021-10-08 | ||
US17/497,033 US20220037976A1 (en) | 2020-07-28 | 2021-10-08 | Electric stepper motor |
US17/501,424 | 2021-10-14 | ||
US17/501,424 US20220037965A1 (en) | 2020-07-28 | 2021-10-14 | Electric motor with positional sensing |
US17/534,390 | 2021-11-23 | ||
US17/534,390 US20220082129A1 (en) | 2020-07-28 | 2021-11-23 | Magnetic bearing |
Publications (1)
Publication Number | Publication Date |
---|---|
CA3150497A1 true CA3150497A1 (en) | 2022-04-10 |
Family
ID=81206858
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA3150497A Pending CA3150497A1 (en) | 2021-07-22 | 2022-02-28 | Magnetic bearings and electric motors |
Country Status (1)
Country | Link |
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CA (1) | CA3150497A1 (en) |
-
2022
- 2022-02-28 CA CA3150497A patent/CA3150497A1/en active Pending
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