AU2012361425B2

AU2012361425B2 - Permanent magnet harmonic motor

Info

Publication number: AU2012361425B2
Application number: AU2012361425A
Authority: AU
Inventors: Linni JIAN; Yuanyuan Wu; Guoqing Xu
Original assignee: Shenzhen Institute of Advanced Technology of CAS
Current assignee: Shenzhen Institute of Advanced Technology of CAS
Priority date: 2011-12-29
Filing date: 2012-12-28
Publication date: 2015-04-16
Anticipated expiration: 2032-12-28
Also published as: CN102570753A; CN102570753B; WO2013097766A1; AU2012361425A1

Abstract

A permanent magnet harmonic motor comprises: a rotor mechanism (1) with several permanent magnets (2) disposed thereon, a stator mechanism (3) fitted with the rotor mechanism (1), and a support mechanism (8) with a bearing assembly (10) disposed thereon. The rotor mechanism (1) is connected to the support mechanism (8) through the bearing assembly (10); magnetic regulating teeth (4) are circumferentially formed at a part of the stator mechanism (3) close to the rotor mechanism (1), and distributed windings (6) are arranged on the magnetic regulating teeth (4). The number of parts in the permanent magnet harmonic motor is reduced; the permanent magnet harmonic motor has a simpler structure, and an assembly process is simple. In addition, the weight of the whole motor is reduced, and the size of the motor is reduced, which facilitate the reduction in the unsprung mass of an electric vehicle, thereby improving the stability and riding comfort of the vehicle.

Description

- 1 PERMANENT MAGNET HARMONIC MOTOR FIELD OF INVENTION [0001] The present invention relates to a permanent magnet harmonic motor. BACKGROUND OF INVENTION [0002] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. [0003] In order to resolve the problems of the world's energy intensity and the environmental pollution, electric vehicles, which have significant advantages of high efficiency and low emission, become the hotspot in the researches of automobile manufacturers and research institutes, and especially, the electric vehicle with a hub motor driving system of high efficiency and high power density is considered to be provided with the most advanced way of driving . [0004] The motor acts as a core part of a hub driving vehicle, and a motor with a high performance plays a decisive role in the rapid development of electric vehicles. Currently, hub driving electric vehicles mainly have two kinds of driving motors: outer rotor motors and inner rotor motors. In order to satisfy the requirement of the actual rotating speed of the wheels, the inner rotor motors need to be equipped with a set of complicated planet gear decelerating mechanisms, and the volume and the weight of the whole transmission system greatly are greatly increased as well as the investment cost is increased correspondingly. In addition, loud noise, low efficiency, low transmission accuracy and slow response are also the disadvantages thereof, and the wearing of the gearbox will decrease the lifetime and the reliability of the system. As for the outer rotor motors with low rotating speed range and high torque characteristics, due to the requirement of the actual rotating speed of the rotating speed range composited wheels, it is, generally, not required to be equipped with decelerating mechanisms, and the wheels are directly driven by the outer rotor of the motor. Chinese patent literature with publication number CN101789667A discloses an outer rotor composited permanent magnetic brushless hub motor of electric vehicle, which comprises an outer rotor, a supporting shaft connected with the outer rotor, an outer rotor yoke disposed at an inner wall of the outer rotor, permanent magnets evenly embedded on the outer rotor yoke in a circumferential direction, a magnetic regulating ring connected with the permanent magnets -2 and fixed on the supporting shaft, a stator disposed between the magnetic regulating ring and the supporting shaft and fixed on the supporting shaft, a winding wound around the stator, and a bearing and a rotating shaft disposed on the supporting shaft. This motor operates by performing energy conversion with the magnetic field of the stator after directly magnetic field modulating the permanent magnets of the outer rotor of a magnetic gear using the magnetic regulating ring, while an inner rotor of the magnetic gear and an outer rotor portion of the motor are removed. Although the magnetic regulating ring adopted by the motor is in a static state relative to the stator, the amount of parts is relatively large, which results in a relatively complex structure of the harmonic motor, while the manufacturing and the assembling process are relatively complex. SUMMARY OF INVENTION [0005] In this case, the technical problems to be resolved by the present invention is that the motor in prior arts may comprises the excessive number of parts and the complicated structure of the harmonic motor of the prior art, such that a new permanent magnet harmonic motor with relatively small number of parts and a simply structure is required. [0006] To this end, the present invention provides a permanent magnet harmonic motor comprising: a rotor mechanism, with a plurality of permanent magnets disposed thereon; a stator mechanism, fitted with the rotor mechanism; and a supporting mechanism, with a bearing assembly disposed thereon and with the rotor mechanism connected with the supporting mechanism through the bearing assembly, wherein magnetic regulating teeth are circumferentially formed on a portion of the stator mechanism close to the rotor mechanism, and have distributed windings disposed thereon; the stator mechanism has concentrated windings disposed thereon, and the number of pole pairs of the concentrated windings is equal to that of the distributed windings, which are both equal to the number of pole pairs of windings of the stator mechanism. [0007] Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". [0008] In the above mentioned permanent magnet harmonic motor, the stator mechanism has concentrated windings disposed thereon, and the number of pole pairs of the concentrated -3 windings is equal to that of the distributed windings, which are both equal to the number of pole pairs of windings of the stator mechanism. [0009] In the above mentioned permanent magnet harmonic motor, the stator mechanism has stator grooves evenly disposed thereon, separating a stator into a plurality of stator teeth, each of which has a plurality of magnetic regulating teeth arranged thereon and has the concentrated windings disposed thereon. [0010] In the above mentioned permanent magnet harmonic motor, the magnetic regulating teeth are protrusions circumferentially formed on a portion of the stator mechanism close to the rotor mechanism and extend in a radial direction. [0011] In the above mentioned permanent magnet harmonic motor, the number of the magnetic regulating teeth is equal to a sum of the number of pairs of the permanent magnets embedded within the rotor mechanism and the number of pole pairs of windings of the stator mechanism. [0012] In the above mentioned permanent magnet harmonic motor, the permanent magnets are embedded within the rotor mechanism. [0013] In the above mentioned permanent magnet harmonic motor, the rotor mechanism is an outer rotor mechanism and the stator mechanism is an inner stator mechanism; or the rotor mechanism is an inner rotor mechanism and the stator mechanism is an outer stator mechanism. [0014] In the above mentioned permanent magnet harmonic motor, the outer rotor mechanism comprises an outer rotor and an end cover disposed outside the outer rotor, and the end cover is connected with the supporting mechanism through the bearing assembly; and the inner stator mechanism comprises an inner stator and a shaft connected with the inner stator. [0015] In the above mentioned permanent magnet harmonic motor, the permanent magnets are arranged in a V-shaped manner and are rectangular permanent magnets, and polarities of every two adjacent permanent magnets arranged in the V-shaped manner are opposite.

-4 [0016] In the above mentioned permanent magnet harmonic motor, the stator mechanism and the rotor mechanism are of a concentric topological structure, and the stator mechanism and the rotor mechanism have an air gap disposed therebetween. [0017] In the above mentioned permanent magnet harmonic motor, the stator grooves have insulating and non magnetic-conductive filling parts disposed therein for separating the distributed windings and the concentrated windings. [0018] In the above mentioned permanent magnet harmonic motor, the permanent magnets are neodymium-iron-boron permanent magnets. [0019] In the above mentioned permanent magnet harmonic motor, the stator and the rotor are both formed by laminating silicon steel sheets. [0020] In the above mentioned permanent magnet harmonic motor, a supporting body of the outer rotor and an end cover of the outer rotor are fixed on an outer circumference of the bearing mechanism. The stator is fixed on a shaft. [0021] In the above mentioned permanent magnet harmonic motor, the supporting mechanism is a barrel body. [0022] In an electric vehicle having a hub driving motor, the motor is any of the above mentioned permanent magnet harmonic motors. [0023] In a wind turbine generator having a wind-driven motor, the wind-driven motor is any of the above mentioned permanent magnet harmonic motors. [0024] In the above mentioned wind turbine generator, the concentrated windings and the distributed windings are connected in series along a forward direction or connected in series along a reverse direction. [0025] In comparison with the prior art, the above mentioned technical solutions of the present invention have following advantages: 1. In the permanent magnet harmonic motor of the present invention, the magnetic regulating teeth are circumferentially formed on the portion of the stator mechanism close to the rotor mechanism, the magnetic regulating teeth have distributed windings disposed thereon, which removes the structure of the magnetic regulating ring, such that the number of -5 inner parts of the harmonic motor is relatively small, and the structure is simpler, thereby simplifying the assembling process; in addition, by saving the structure of the independent magnetic regulating ring, the weight of the whole motor is further reduced, and the size of the motor is reduced, which facilitates the decreasing of the non-spring loaded mass, such that the stability and the smoothness of the vehicle are improved. 2. The stator mechanism have the concentrated windings disposed thereon, and the concentrated windings and the distributed windings are arranged in stack, and such kind of design may maintain a relatively high torque outputting capacity during a weak magnetic acceleration control of the motor, so as to satisfy the requirement of a high rotating speed while the electric vehicle is running on an expressway; and a torque output greater than that of a single set of windings is provided at a low speed, so as to satisfy the requirement of a great torque while the electric vehicle is running at a low speed or is climbing. 3. The number of the magnetic regulating teeth is equal to a sum of the number of pairs of the permanent magnets embedded within the rotor mechanism and the number of pole pairs of windings of the stator mechanism, which makes one certain generated harmonic magnetic field identical with the number of pole pairs of the stator of the motor for delivering power, so as to reduce the number of pole pairs of the stator of the motor and the number of grooves, reducing the processing difficulty. BRIEF DESCRIPTION OF THE DRAWINGS [0026] In order to make the contents of the present invention more readily and clearly understandable, hereinafter, the present invention will be further described in details according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein Fig. 1 is a structural view of a harmonic motor with an outer rotor and an inner stator; Fig. 2 is a side view of the harmonic motor with the outer rotor and the inner stator; Fig. 3 is a distribution diagram of distributed windings; Fig. 4 is a distribution diagram of concentrated windings; Fig. 5 is a structural view of a harmonic motor with an outer stator and an inner rotor; and Fig. 6 is a cross-sectional view of the harmonic motor with the outer stator and the inner rotor. [0027] What the reference signs in the drawings represent: 1-rotor mechanism, 2-perminant magnets, 3-stator mechanism, 4-magnetic regulating teeth, 5-concentrated windings, 6-distributed windings, 7-insulating and non -6 magnetic-conductive filling parts, 8-supporting mechanism, 9-end cover, 10-bearing assembly, and 11-shaft. DETAILED DESCRIPTION OF EMBODIMENTS Embodiment 1 [0028] The permanent magnet harmonic motor as shown in Fig. 1 comprises a rotor mechanism 1, with a plurality of permanent magnets 2 disposed thereon; the shape of the permanent magnet 2 may be various, and preferably, the permanent magnet 2 is in a rectangular shape; the connection relationships of the permanent magnets 2 and the rotor mechanism are various, and preferably, the permanent magnets 2 is embedded within the rotor mechanism, such that the permanent magnets may hardly drop out when the rotor is in a high speed rotating process; in addition, the arrangement manner of the permanent magnets 2 may be various, and preferably, the permanent magnets 2 are arranged in a V-shaped manner, and polarities of every two adjacent permanent magnets arranged in the V-shaped manner are opposite; the harmonic motor also comprises a stator mechanism 3 fitted with the rotor mechanism 1, wherein an air gap exists between the stator mechanism 3 and the rotor mechanism 1; the harmonic motor further comprises a supporting mechanism 8, wherein the supporting mechanism 8 has a bearing assembly 10 disposed thereon and the rotor mechanism 1 is connected with the supporting mechanism 8 through the bearing assembly 10; and magnetic regulating teeth 4 are circumferentially formed on a portion of the stator mechanism 3 close to the rotor mechanism 1, and the magnetic regulating teeth 4 have distributed windings 6 disposed thereon. In the present embodiment, the rotor mechanism 1 is an outer rotor mechanism, and the stator mechanism 3 is an inner stator mechanism. As shown in Fig. 2, the outer rotor mechanism comprises an outer rotor and an end cover 9 disposed outside the outer rotor, and the end cover 9 is connected with the supporting mechanism 8 through the bearing assembly 10; and the supporting mechanism may be a barrel body, and the inner stator mechanism comprises an inner stator and a shaft 11 connected with the inner stator. [0029] In order to maintain a relatively high torque outputting capacity of the motor during a weak magnetic acceleration control, the requirement of a high rotating speed while an electric vehicle is running on an expressway is satisfied; and a torque output greater than that of a single set of windings is provided at a low speed, and the requirement of a great torque while the electric vehicle is running at a low speed or is climbing is satisfied. Concentrated windings 5 may be disposed on the stator mechanism 3, and the number of pole pairs of the -7 concentrated windings is equal to that of the distributed windings, which are both equal to the number of pole pairs of windings of the stator mechanism, The preferred connecting manner of the distributed windings and the concentrated windings are those shown in Figs. 3 and 4. The distributed windings 6 and the concentrated windings have insulating and non magnetic conductive filling parts 7 disposed therebetween, so as to separate the distributed windings 6 from the concentrated windings 5, as shown in Fig.1. [0030] In order to further simplify the structure of the magnetic regulating teeth, and to obtain a better magnetic regulating effect, the regulating teeth are formed as protrusions circumferentially formed on a portion of the stator mechanism close to the rotor mechanism and extend in a radial direction. [0031] In order to make one certain generated harmonic magnetic field identical with the number of pole pairs of the stator of the motor for delivering power so as to allow reduce the number of pole pairs and the number of grooves of the stator of the motor and further lower the processing difficulty for the grooves of the stator, the number of the magnetic regulating teeth is preferably equal to a sum of a number of pairs of the permanent magnets embedded within the rotor mechanism and the number of pole pairs of windings of the stator mechanism. [0032] Pr represents the number of pole pairs of the permanent magnets of the outer rotor, ns represents the number of magnetic regulating blocks, ps represents the number of pole pairs of the windings, and Gr represents the ratio of the rotating speeds of the magnetic fields of the rotor and the stator. [0033] Following basic conditions should be satisfied when the harmonic motor operates stably: Condition for the numbers of pole pairs: Pr= ns-ps (1) The ratio of the rotating speeds of the magnetic fields of the rotor and the stator: Gr = (ps - ns) / ps (2) [0034] Parameters for the numbers of pole pairs of the motor of the present embodiment are: 16 pairs of permanent magnets and 18 magnetic regulating teeth 4. From the above equation (1), it can be known that the number of the magnetic pole pairs of the windings of the stator ps is 2, and therefore in the present embodiment, both the number of pole pairs of the concentrated windings 5 and that of the distributed windings 6 are 2 pairs, as shown in the -8 winding distribution diagrams of Figs. 3 and 4. From the above equation (2), it can be known that the ratio of the rotating speeds of the magnetic fields of the rotor and the stator G, is -8, and therefore, the rotating speed of the outer rotor is merely one eighth of the rotating speed of the rotor of a typical motor with the same number of pole pairs of the rotor, and the rotation direction of the magnetic field of the stator is opposite to the rotation direction of the rotor. If the frequency of the power supply for an electric vehicle is 50Hz and it may be determined that the rotating speed of the rotating magnetic field of the stator is 1500rpm, the rotating speed of the outer rotor is 187.5rpm, which may satisfy the speed requirement for the electric vehicle to run. [0035] The motor of the present embodiment may be used in an electric vehicle as a hub driving motor. [0036] In addition, the motor of the present embodiment may be used in a wind turbine generator as the wind turbine generator. When used in the wind turbine generator, the concentrated windings and the distributed windings may be connected in series in a forward direction or be connected in series in a reverse direction, which may depend on the speed of wind, and the connection manner of the two windings may be selected through a connection selecting device, wherein the series connection in the forward direction may be applied when the speed of wind is relatively slow, and the series connection in the reverse direction may be applied when the speed of wind is excessively fast, such that the rotating speed of the blades is maintained within the normal operating range of the machine set design. Embodiment 2 [0037] Referring to the permanent magnet harmonic motor as shown in Figs. 5 and 6, the motor of the present embodiment differs from that of Embodiment 1 in that the rotor mechanism is an inner rotor mechanism, and the stator mechanism is an outer stator mechanism. [0038] Referring to Fig. 6, in the present embodiment, the outer stator, a supporting mechanism 8 and an end cover 9 are fixed on an outer circumference of a bearing assembly 10, respectively. The rotor is fixed on a shaft 11, and the supporting mechanism may be a barrel body.

-9 [0039] Apparently, the above embodiments are merely examples for the clarity of describing, rather than limitations of the implements. As for one ordinary skilled in the art, other various changes or modifications may be made based on the above descriptions. Exhaustion for all the implements is not required or possible. Obvious changes or modifications derived therein still fall within the protection scope of the present invention.

Claims

1. A permanent magnet harmonic motor comprising: a rotor mechanism, with a plurality of permanent magnets disposed thereon; a stator mechanism, fitted with the rotor mechanism; and a supporting mechanism, with a bearing assembly disposed thereon and with the rotor mechanism connected with the supporting mechanism through the bearing assembly, wherein magnetic regulating teeth are circumferentially formed on a portion of the stator mechanism close to the rotor mechanism, and have distributed windings disposed thereon; the stator mechanism has concentrated windings disposed thereon, and the number of pole pairs of the concentrated windings is equal to that of the distributed windings, which are both equal to the number of pole pairs of windings of the stator mechanism.

2. The permanent magnet harmonic motor of claim 1, wherein the stator mechanism has stator grooves evenly disposed thereon, separating a stator into a plurality of stator teeth, each of which has a plurality of magnetic regulating teeth arranged thereon and has the concentrated windings disposed thereon.

3. The permanent magnet harmonic motor of claim 1, wherein the magnetic regulating teeth are protrusions circumferentially formed on a portion of the stator mechanism close to the rotor mechanism and extend in a radial direction.

4. The permanent magnet harmonic motor of any one of claims 1 to 3, wherein the number of the magnetic regulating teeth is equal to a sum of the number of pairs of the permanent magnets embedded within the rotor mechanism and the number of pole pairs of windings of the stator mechanism.

5. The permanent magnet harmonic motor of claim 4, wherein the permanent magnets are embedded within the rotor mechanism.

6. The permanent magnet harmonic motor of claim 5, wherein the rotor mechanism is an outer rotor mechanism and the stator mechanism is an inner stator mechanism; or the rotor mechanism is an inner rotor mechanism and the stator mechanism is an outer stator mechanism. - 11

7. The permanent magnet harmonic motor of claim 6, wherein the outer rotor mechanism comprises an outer rotor and an end cover disposed outside the outer rotor, and the end cover is connected with the supporting mechanism through the bearing assembly; and the inner stator mechanism comprises an inner stator and a shaft connected with the inner stator.

8. The permanent magnet harmonic motor of claim 7, wherein the permanent magnets are arranged in a V-shaped manner and are rectangular permanent magnets, and polarities of every two adjacent permanent magnets arranged in the V-shaped manner are opposite.

9. The permanent magnet harmonic motor of claim 1, wherein the stator mechanism and the rotor mechanism are of a concentric topological structure, and the stator mechanism and the rotor mechanism have an air gap disposed therebetween.

10. The permanent magnet harmonic motor of claim 1, wherein the stator grooves have insulating and non magnetic-conductive filling parts disposed therein for separating the distributed windings and the concentrated windings.

11. The permanent magnet harmonic motor of claim 1, wherein the permanent magnets are neodymium-iron-boron permanent magnets.

12. The permanent magnet harmonic motor of claim 1, wherein the stator and the rotor are both formed by laminating silicon steel sheets.

13. The permanent magnet harmonic motor of claim 6, wherein a supporting body of the outer rotor and an end cover of the outer rotor are fixed on an outer circumference of the bearing mechanism, and the stator is fixed on a shaft.

14. The permanent magnet harmonic motor of claim 1, wherein the supporting mechanism is a barrel body.

15. An electric vehicle having a hub driving motor, wherein the motor is a permanent magnet harmonic motor according to any one of claims 1 to 14.

16. A wind turbine generator having a wind-driven motor, wherein the wind-driven motor is a permanent magnet harmonic motor according to any one of claims 1 to 14. -12

17. The wind turbine generator of claim 16, wherein the concentrated windings and the distributed windings are connected in series along a forward direction or connected in series along a reverse direction.