WO2023084295A1

WO2023084295A1 - Stepper axial flux electric motor with dc two polar pair rotor and stator

Info

Publication number: WO2023084295A1
Application number: PCT/IB2021/060535
Authority: WO
Inventors: Amir Hossein BABAJANI
Original assignee: Babajani Amir Hossein
Priority date: 2021-11-14
Filing date: 2021-11-14
Publication date: 2023-05-19

Abstract

The invention discloses an axial flux DC motor that converts electrical energy into mechanical one and consists of at least one rotor in turn rotor or rotors themselves consist of at least one circular plate and four permanent semicircular magnets. On each side of the rotor, there are 2 magnets and the corresponding antilogous pole magnets are located on the other side of the rotor. The rotor moves by the change in the flux of the stators. Each stator consists of two coils or armatures.

Description

Title of Invention : Stepper axial flux electric motor with DC two polar pair rotor and stator

Technical Field

[0001 ] The technical field of this invention relates to the axial flux electric motor which can be utilized in a wide variety of devices.

Background Art

[0002] An invention entitled A SEALED AXIAL FLUX MOTOR WITH INTEGRATED COOLING with registration number WO2019241765has been published.

[0003] Conventional axial flux motors typically include multiple rotors and stators resulting in a larger and heavier motor. Additionally, conventional axial flux motors include a housing to protect the rotors and stators, but the housing is often difficult to seal from the environment leading to risks of contaminants (e.g., dirt, water) infiltrating the motor and causing failure over time. The present invention overcomes these limitations by disclosing an axial flux motor with a single rotor and two stators. The use of a single rotor reduces the size and weight of the motor. An inboard housing and an outboard housing mechanically support the two stators and are joined together to define an interior cavity. A ring seal is disposed between the two housings to ensure the interior cavity is sealed. Additionally, the two stators may actuate multiple degrees of freedom (DOF) including the rotation of a wheel and actuation of a suspension.

[0004] The main advantage of this invention is to seal the electric motor, in turn, makes better utilization of coolants and at the same time using coolant makes it more complicated and raises the volume of the electric motor, but it makes it possible to use high-density cores. This motor because of embedding high- density cores that generate more heat, requires coolants so that the generated heat does not damage the coils and their parts and does not reduce the magnetic force efficiency of its magnets, and due to these drawbacks, generated heat must be released from the system.

Technical Problem [0005] In different kinds of de electric motors to create directional motion various methods including shutting off some poles, flux density difference, or creating separate poles in the rotor or the difference in the number of poles of the rotor and stator are used and these approaches each reduce the motor efficiency in different ways. Another issue is the lack of high efficiency along with the high core flux density, which, in case, both issues occur, there will be urgent needs to coolant, which in turn it has its weakness. Another limitation is the high magnetic flux leakage in existing electric motors and the unequal number of the rotor and stator poles due to the direction of motion, and the final issue is the low torque and efficiency of stepper motors.

[0006] Objectives of the invention include making a directed and directional motion as well as using all poles and all pole forces and the simultaneous utilization of absorption and repulsion forces, as well equal level and the number of poles of the rotor and stator and another objective is to attain high efficiency using high flux density cores and reducing leakage flux in the motor and also the invention aims to improve efficiency and torque of the motor compared to the existing stepper motors, which will be achieved by axial flux structure and the aforementioned goals.

Solution to Problem

[0007] The invention discloses an axial flux DC motor that converts electrical energy into mechanical one and consists of at least one rotor in turn rotor or rotors themselves consist of at least one circular plate and four permanent semicircular magnets. On each side of the rotor, there are 2 magnets and the corresponding antilogous pole magnets are located on the other side of the rotor. The rotor moves by the change in the flux of the stators. Each stator consists of two coils or armatures.

[0008] To reach more power and accuracy, the number of the rotor and stator can be increased. For doing this, the rotor and stator can be arranged in two manners. In one case, the arrangement can be started with a rotor and one stator can be embedded between two rotors. In the other case, the arrangement starts with the stator, and a rotor is placed in front of both stators. The number of stators formula in one case is (na_1 ) and in the other case is (na + 1 ). Advantageous Effects of Invention

[0009] This invention is more efficient in terms of reducing electrical energy consumption compared to peer models and at the same time, it has more efficient mechanical energy production. Generating more mechanical energy along with equal volume can lead to better energy consumption. Also, producing equal mechanical energy along with a smaller volume makes it easier and less expensive to use in different case.

[0010] This motor given the production of more mechanical energy in equal volumes in similar models is cost-effective and in models, with equal power, this motor will use less raw materials and electrical energy. Because of simpler structure than similar models, less energy is required to develop it, and as a result, it is more environmentally friendly to develop and use than others.

[0011] 1 - The more stators and rotors, the more accurate the rotation angle of the rotor.

[0012] 2- Reduction of flux leakage

[0013] 3- Increased surface area of magnets

[0014] 4- Simultaneous use of the of attraction and repulsion force of all poles

[0015] 5- Using high flux density cores without the need for coolant

[0016] 6- Asynchronous flux change of stators

Brief Description of Drawings

[0017] Fig 1 - Motor exploded view drawing

[0018] Fig 2- Motor view with connected parts

[0019] Fig 3- Stator interior view

Description of Embodiments

[0020] Figure 1 illustrates the parts of this invention. Each motor has at least one circular rotor (2) and at least two circular stators (1 and 3). On each side of each rotor, there are two permanent semicircular magnets (5a and 5b), the corresponding magnets on the other side of the rotor are antilogous. [0021] The rotor magnets (5a and 5b) are semicircular and two of them are installed on one side of the plates so that they are antilogous and form a circle together. The center of the magnets is empty for the shafts and stator bearings. The two magnets are placed on the other side of the rotor in a way that is antilogous with the magnets on the other side and attracts each other and these plates, which now have magnets, are connected to the shaft by the outer part of the inner ring of bearings that are closer to the shaft (6) (figure 2). As a result of such connection, the stators are connected from the outside, and after connecting to the motor body, they will remain fixed and the rotor, which is connected to the stators from the center can rotate freely. Figure 3 illustrates that there is a place on both sides of the stator to install the bearings (301 ). Each stator has two cores (302) and a coil, or armature, in which the coiled cores have the same size and shape as the rotor's permanent magnets.

[0022] Such two pair-poles structure of rotors and stators reduces leakage flux and increases the pole level of magnets compared to existing motors and existing models, in turn, improves the efficiency and torque of the motor. In addition, in order to have a directed and directional movement, a second stator is required, whose structure is the same as the previous stator, but its position is 90 degrees of rotation relative to the other stator poles, and this position is such that the rotors and stators are placed parallel to each other and the stators are positioned at certain angles to the poles of the other stators in respect to their number.

[0023] The position of the stator poles to the number of stators is such that in the least case where there are two stators on either side of a rotor, the angle of the stators relative to each other is 90 degrees.

[0024] In case the number of stators is increased to three, with two rotors between them, the angle of the stators relative to each other is 60 degrees. In this way, in the case of dividing the angle of 180 degrees by the number of stators, the angle of the stators relative to each other is attained.

[0025] Due to the difference in the degrees of the stators relative to each other the angle of directional motion is created so that when the poles on one side of the rotor are fully attracted and at the same time the stator poles are repelled first if the motor has two stators, the poles on the other side of the rotor are located halfway to attract the next poles and repel the previous ones, so that the north pole of the rotor attracts the south pole of the stator and at the same time the north pole repels the stator and the south rotor attracts the north pole of the stator while south pole repels stator.

[0026] This state triggers the rotor to move in a certain direction and at the same moment the first stator, which is completely attracted and repelled, one of the poles of the rotor is detected by various magnetic sensors and causes a flux change in the first stator and this flux change causes a repulsive force on the opposite poles and attracts the next poles. The same action happens when the rotor poles are completely attracted and at the same time, the second stator poles are repelled, which in turn causes the rotor and motor to continue moving.

[0027] [Any flux change produces heat in the core and the main source of this heat is a change in the direction of magnetic hysteresis in the core, and the higher the flux density of the core, the higher the magnetic hysteresis of its magnetic domains, resulting in much heat production in the core, this heat dissipation in the magnetic is called hysteresis losses and], due to the separate and asynchronous stator flux change and finally the reduction of flux change, in each cycle, so that each stator changes twice fluxes to complete a cycle of the rotor, reduces and distributes the heat generated in the stator cores, and the asynchronous flux change of the stators causes the second stator to change heat when the first stator changes the flux. At the same time, the second stator is cooled or losses heat. Therefore, high-flux density cores can be used in those motors that do not use coolant.

[0028] In case the stators do not change the flux, the motor can remain fixed at the same moment and degree. Therefore, this motor can act like stepper motors, but with some differences, one of which is their grading. In this regard, the more stators, the more stopping can occur in higher angels and other differences due to the axial flux structure and reduction of leakage flux and increase of pole level and use of cores with high flux density increase torque and efficiency compared to existing stepper motors and also some differences are due to more complicated control of motor and the simultaneous using force of attraction and repulsion of all poles. Example

[0029] every rotor (2) consists of four permanent magnets (5a and 5b) and one or more circular steel plates or plates made of ferromagnetic materials that have the property of attracting magnets so that the permanent magnets can be connected to it easily and the magnets on both sides of the plates can unite their force, and these plates are connected by a welding spot device or any action that causes the plates to be connected, and even plates of materials that cannot be attracted to the magnet can be used. If the plates have the desired strength and structure, they can also be made of aluminum and carbon fiber. On the other hand, these plates have a hole in their center equal to the radius of the motor shaft.

[0030] Each rotor instead of using four permanent magnets can use two electromagnetic magnets as same as stators. The stator frame consists of three parts, which are two parts of the frame in such a way that at least one bearing is placed on its edges from the outside and restrain it, and the cores are placed on both sides of the two parts of the frame so that the edges of the two parts of the frame are located below the edges of the cores and part of the coils are placed between the two parts of the frame and the cores and these parts are held together by the third part of the frame and the third part, which is in the form of an open-ended circle and has edges as the same as the other parts of the frame to fix the cores in place, and the open part of the third part of the frame can be closed and tightened by any system.

[0031] The rotors and stators are held together by a threaded shaft and two nuts and washers that act to create space between the rotors and stators, and the motion control part consists of magnetic sensors and processor drivers and boards.

Industrial Applicability

[0032] The invention discloses an axial flux DC motor that converts electrical energy into mechanical one and it can be used in any device that needs a motor.

[0033] On the other hand, this device can produce like an alternator in case of mechanical energy transfer by electrical energy. This method is used in electric vehicles when the car is downhill. In this case, these alternators can convert potential energy into renewable electrical energy.

Claims

[Claim 1 ] DC axial flux electric motor which consists of the following parts: a. a. Circular rotor equipped with 2 semi-circular magnets on each side b. b. Stator

[Claim 2] According to the claim 1 , the circular rotor consists of four permanent semicircular magnets with two magnets on each side of the rotor, and the corresponding magnets on the other side of the rotor are antilogous.

[Claim 3] According to claim 1 , the stator has two semicircular cores, and stators are connected from the outside, and after connecting to the motor body, they will remain fixed and the rotors, which is connected to the stators from the center and can rotate freely.

[Claim 4] According to claims 1 to 3, the angle of the semicircular cutting line of the stator cores concerning the adjacent stator is determined by dividing the number of stators by 180, In a motor with three stators, the difference between the cutting angle of the semicircle of the stator cores and the next stator is 60 degrees.

[Claim 5] According to claims 1 to 4, if the motor has two stators, when one of the stators is in full absorption and repulsion of the poles on one side of the rotor the poles on the other side of the rotor are located halfway to attract the next poles and repel the previous ones, so that the north pole of the rotor attracts the south pole of the stator and at the same time the north pole repels the stator and the south rotor attracts the north pole of the stator while south pole repels stator and triggers the rotor to move.

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