WO2018022029A1

WO2018022029A1 - Electric motor

Info

Publication number: WO2018022029A1
Application number: PCT/US2016/044127
Authority: WO
Inventors: Keqin JIANG; Edward Tao GAO; Zheng Chen; Haijiang Zhang
Original assignee: Jiang Keqin; Gao Edward Tao; Zheng Chen; Haijiang Zhang
Priority date: 2016-07-26
Filing date: 2016-07-26
Publication date: 2018-02-01

Abstract

In one aspect, an electric motor may include a stator with a stator coil, a rotor with a rotor coil, a control circuit, a brush and commutator, a housing and a shaft. The stator and the stator coil are contained and fixed with respect to the housing, while the rotor and the rotor coil are able to rotate with respect to the housing. The electric motor may further include a rotating coil and a stationary coil to replace conventional brush and commutator. It is noted that an air gap is formed between the rotating coil and stationary coil, so there is no abrasion between these two coils. In another aspect, the motor can be used as a power generator.

Description

ELECTRIC MOTOR

FIELD OF THE INVENTION

[0001 ] The present invention relates to an electric motor, and more particularly to an electric motor using a rotating coil and a stationary coil, which are not in contact, to replace conventional brushes and commutator.

BACKGROUND OF THE INVENTION

[0002] An electric motor is an electrical machine that converts electrical energy into mechanical energy. In normal motoring mode, most electric motors operate through the interaction between an electric motor's magnetic field and winding currents to generate force within the motor. More specifically, the motor's armature current is supplied through stationary brushes in contact with revolving commutator, which causes required current reversal and applies power to the machine in an optimal manner as the rotor rotates from pole to pole. Since the brushes have to be in contact with the commutator when the motor is working, the wear on the brushes and commutator is inevitable, the problem of which may be worse when the speed of the motor is high.

[0003] To solve the problems of conventional electric motors, brushless motors have been developed. Brushless motors are typically more efficient and quieter than conventional motors because brushless motor is designed to avoid the problem stated above. However, the costs associated with the manufacture of brushless motors are usually greater than conventional motors. For example, brushless motors can be more expensive than conventional motors because of the control circuitry necessary to drive the brushless motors.

[ 0004 ] Although different brushless motors can vary in configuration, all brushless motors run on direct current and include circuitry to sequentially switch the direct current into one or more stator coils. In addition, most brushless motors include a plurality of permanent magnets attached to a rotor.

[0005] With reference to FIG. 1, a conventional direct current brushless motor for a fan has a housing 31, a stator assembly 30 and a rotor assembly. The stator assembly 30 is contained in and fixed with respect to the housing 31. The rotor assembly is contained in and able to rotate with respect to the housing 31. The rotor assembly includes a metal cover 312 under the housing 31, four magnetic sectors evenly arranged under and along the metal cover 312, and a shaft 311. Each magnetic sector is made up of a permanent magnet 313. The stator assembly 30 consists of four stator poles 301 evenly arranged on a round seat, a sleeve 33, a circuit board 32, and a sensor 321 electrically connected to the circuit board 32 and fixed between two stators poles 301. The round seat covers the sleeve 33. The sleeve 33 is connected to the shaft 311 by a bearing 34. The sensor 321 is used to sense the magnetic strength of the permanent magnets 313 and send signals to the circuit to activate the motor and keep the motor running. Before the motor is activated, the sensor 321 always stops with a sensing window 322 stopping right above where two neighboring permanent magnets 313 meet.

[0006] However, this kind of brushless motor is disadvantageous because the magnetic strength where two neighboring permanent magnets 313 meet is the weakest, so it cannot be used in some situations especially when a great torque is needed at the beginning. The magnetic force may also decrease after a period of time.

[0007] Therefore, there remains a need for a new and improved design for an electric motor to overcome the problems in conventional motors and brushless motors.

SUMMARY OF THE INVENTION

[0008] The present invention is an improvement of AC and DC motors' brushes through the use an electromagnetic induction technology instead of the contact between the brushes and commutator in conventional motors. Through electronically controlled magnetic phase, the electric power is transmitted to each rotor coil windings. Because the rotor rotates without metal contact, so there is no spark, temperature rise, and wear. So, the motor can have high instantaneous torque power with high speed and efficiency. Also, it can be maintenance-free. Since an electromagnetic induction technology is used in the present invention, there is no electricity leakage. The motor can even be functioning in water or liquids without being completely sealed, and the motor housing can be designed as open-ended. Namely, the motor in the present invention can be a waterproof and wear-free motor.

[0009] For the generator in the present invention, since the conventional brushes are replaced by using electromagnetic induction between the rotating magnetic coil and the stationary magnetic coil, the generator has no friction and less waste of power, which can extend the life of generator.

[0010] Conventional motors send power and commute magnetic by brushes and commutator. The present invention is configured to use electromagnetic induction through electric power transmission to the rotor to replace conventional brushes, and transmit and receive magnetic commutation control signal to overcome the problems in conventional motors.

[0011 ] In one aspect, a motor may include a stator with a stator coil, a rotor with a rotor coil, a control circuit, a housing and a shaft. The stator and the stator coil are contained and fixed with respect to the housing, while the rotor and the rotor coil are able to rotate with respect to the housing.

[0012] The electric motor in the present invention may further include a rotating coil and a stationary coil to replace conventional brushes and commutator. It is noted that an air gap is formed between the rotating coil and stationary coil, so there is no abrasion between these two coils.

[0013] When in use, the electrical energy is input from the stationary coil and can be transmitted to the rotating coil through the electromagnetic induction. Through the control circuit, the electrical energy can be further transmitted to the rotor coil to enable the rotor to rotate. Meanwhile, a signal of the rotating angle of the rotor can be transmitted to the control circuit.

[0014] In one embodiment, a rotor with the rotor coil, and the rotor rotates due to the magnetic phase change (e.g. 90 degrees) of the stator, which is managed by the control circuit utilizing the signal of rotating angle of the rotor. In another embodiment, the permanent magnet can be used for the stator, and the magnetic phase change can be conducted in the rotor. It is noted that because of the air gap, there is no abrasion between the rotating coil and stationary coil, so the rotors in the present invention can rotate in a high efficiency, speed and torque.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a prior art of a brushless motor.

[0016] FIG. 2 is a schematic view of the electric motor in the present invention.

[0017] FIG. 2a is a schematic view of the electric motor in the present invention including an example commutation circuit.

[0018] FIG. 3 is a schematic view of the electric motor used as a power generator in the present invention.

[0019] FIG. 3a is a schematic view of the electric motor used as a power generator in the present invention including an example commutation circuit.

DETAILED DESCRIPTION OF THE INVENTION

[0020] The detailed description set forth below is intended as a description of the presently exemplary device provided in accordance with aspects of the present invention and is not intended to represent the only forms in which the present invention may be prepared or utilized. It is to be understood, rather, that the same or equivalent functions and components may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention.

[0021 ] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices and materials similar or equivalent to those described can be used in the practice or testing of the invention, the exemplary methods, devices and materials are now described.

[0022] All publications mentioned are incorporated by reference for the purpose of describing and disclosing, for example, the designs and methodologies that are described in the publications that might be used in connection with the presently described invention. The publications listed or discussed above, below and throughout the text are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.

[0023] In order to further understand the goal, characteristics and effect of the present invention, a number of embodiments along with the drawings are illustrated as following:

[0024] In one aspect, referring to FIG. 2, an electric motor 200 may include a stator 210 with a stator coil 212, a rotor 220 with a rotor coil 222, a control circuit 230, a housing 240 and a shaft 250. The stator 210 and the stator coil 212 are contained and fixed with respect to the housing 240, while the rotor 220 and the rotor coil 222 are able to rotate with respect to the housing 240.

[0025] The electric motor 200 may further include a rotating coil 260 and a stationary coil 270 to replace conventional brushes and commutator. It is noted that the rotating coil 260 and the stationary coil 270 are not in contact, and an air gap 251 is formed therebetween, so there is no abrasion between these two coils. FIG. 2a is a schematic view of the motor 200 and its commutation circuit, wherein R/R' is the current, C is the phase transitioning capacitor, Most/Most' is the switch, Gl/Gl' is the phase transitioning signal receiving unit, and LED1/LED17LED2/LED2' is the phase transitioning signal emitting unit.

[0026] When in use, the electrical energy is input from the stationary coil 270 and can be transmitted to the rotating coil 260 through the electromagnetic induction. Through the control circuit 230, the electrical energy can be further transmitted to the rotor coil 222 to enable the rotor 220 to rotate. Meanwhile, a signal of the rotating angle of the rotor 220 can be transmitted to the control circuit 230.

[0027] In one embodiment, the rotor 220 rotates due to a magnetic phase change (e.g. 90 degrees) of the stator 210, which is managed by the control circuit 230 utilizing the signal of rotating angle of the rotor 220. In another embodiment, the permanent magnet can be used for the stator, and the magnetic phase change can be conducted in the rotor 220. It is noted that because of the air gap 251, there is no abrasion between the rotating coil 260 and stationary coil 270, so both of above rotors 220 in the present invention can rotate in a high efficiency, speed and torque.

[ 0028 ] In another aspect, the brushless motor can be used as a power generator 300. When in use, the rotor 320 can be rotated through the shaft 350 through an external energy source, and an electrical energy can be generated through the rotation of the rotor 320 due to electromagnetic induction. The electrical energy can be further converted by the control circuit 330, and transmitted to the rotating coil 360 and the stationary coil 370 to output the electrical energy. Again, there is no abrasion between the rotating coil 360 and stationary coil 370 because of the air gap 351, the efficiency of power generation can be significantly increased. FIG. 3a is a schematic view of the power generator 300 and its commutation circuit, wherein K/K' is the switch and Jt is the relay.

[0029] Having described the invention by the description and illustrations above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. In practical applications, according to the specific requirements, the number of poles, excitation mode, structural forms of electromagnetic induction, stator and rotor rotation swaps, etc. to design to fit the specific case. Accordingly, the invention is not to be considered as limited by the foregoing description, but includes any equivalents.

Claims

WHAT IS CLAIMED IS:

1. An electric motor comprising a stator with a stator coil, a rotor with a rotor coil, a control circuit, a shaft, a rotating coil and a stationary coil, wherein the rotating coil and the stationary coil are not in contact, and electrical energy is input from the stationary coil and transmitted to the rotating coil through the electromagnetic induction; the electrical energy is further transmitted to the rotor coil to enable the rotor to rotate through the control circuit, and meanwhile a signal of the rotating angle of the rotor is transmitted to the control circuit to conduct a magnetic phase change of the stator, so that the rotor continues to rotate.

2. The electric motor of claim 1 further comprising a housing, wherein the stator and the stator coil are contained and fixed with respect to the housing, while the rotor and the rotor coil rotate with respect to the housing.