Axial-radial excitation vernier permanent magnet motor

Abstract

The utility model belongs to the technical field of permanent magnet motors, and particularly relates to an axial-radial excitation vernier permanent magnet motor. A stator and a rotor permanent magnet are coaxially sleeved, the stator comprises a stator yoke portion and a plurality of stator teeth, a stator winding is placed in a stator groove, the rotor permanent magnet comprises a first permanent magnet body magnetized in the radial direction and a second permanent magnet body magnetized in the axial direction, and an end cover is static. And the end cover is positioned on the outer side of the rotor second permanent magnet, has an air gap with the rotor second permanent magnet and comprises an end cover yoke part and a plurality of end cover teeth. According to the permanent magnet motor, the magnetic leakage is greatly reduced, the power factor is higher, the size of a motor inverter is smaller under the condition of the same power output, and the cost is lower.

Description

Technical Field

[0001] The utility model belongs to the technical field of permanent magnet motors; more specifically, it relates to an axial-radial excitation vernier permanent magnet motor. Background Art

[0002] Vernier permanent magnet motors have received increasing attention in recent years. Based on the magnetic field modulation effect, this type of motor has the advantages of high torque density and low torque pulsation, and is suitable for low-speed, high-torque direct-drive operation.

[0003] Figures 1 to 3 The schematic diagram of the structure of a conventional surface-mounted vernier permanent magnet motor includes a stator core 1, a stator winding 2, a rotor permanent magnet 3 and a rotor core 4. The stator and the rotor are coaxially mounted, the inner wall of the stator has a groove, and the stator winding is placed in the stator groove. The rotor permanent magnet is magnetized radially, and the magnetization directions of two adjacent permanent magnets are opposite.

[0004] Compared with traditional permanent magnet motors, the number of stator and rotor pole pairs of vernier permanent magnet motors is not equal. In order to better exert the magnetic field modulation effect, the number of rotor excitation pole pairs of vernier permanent magnet motors is usually much higher than the number of stator winding pole pairs. However, this will result in strong armature reaction of the motor and low power factor. The use of a yokeless rotor vernier permanent magnet motor can improve the power factor of the motor, but it will cause a significant decrease in the torque density of the vernier permanent magnet motor. It can be seen that the torque density and power factor of the vernier permanent magnet motor restrict each other. Therefore, it is urgent to propose a vernier permanent magnet motor that takes into account both high torque density and high power factor. Accordingly, this field urgently needs to find targeted solutions to better meet the above technical requirements faced in actual production practice. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the utility model provides an axial-radial excitation vernier permanent magnet motor, which aims to solve the technical problem that the torque density and power factor of the existing vernier permanent magnet motor are difficult to balance.

[0006] To achieve the above-mentioned purpose, the utility model provides an axial-radial excitation vernier permanent magnet motor, which includes a stator core, a stator winding, a rotor permanent magnet and an end cover, wherein the stator and the rotor permanent magnet are coaxially mounted, the stator includes a stator yoke and a plurality of stator teeth, the stator winding is placed in a stator slot, the rotor permanent magnet includes a radially magnetized first permanent magnet and an axially magnetized second permanent magnet, the end cover is stationary, is located on the outside of the rotor second permanent magnet and has an air gap therebetween, and the end cover includes an end cover yoke and a plurality of end cover teeth.

[0007] Furthermore, the stator and the end cover are formed by laminating silicon steel sheets.

[0008] Furthermore, the stator winding is a three-phase AC armature winding.

[0009] Furthermore, the rotor permanent magnets may be made of neodymium iron boron, samarium cobalt or ferrite.

[0010] Furthermore, the first permanent magnets of the rotor are magnetized radially, and the magnetization directions of two adjacent permanent magnets are opposite.

[0011] Furthermore, the second permanent magnet of the rotor is axially magnetized, and the magnetization directions of two adjacent permanent magnets are opposite.

[0012] Furthermore, the number of the end cover teeth is the same as the number of the stator teeth, and the axes of the end cover teeth and the stator teeth coincide.

[0013] Optionally, the stator winding is centralized or distributed.

[0014] Furthermore, the number of stator teeth Z s , rotor permanent magnet pole pair number P r and the number of stator winding pole pairs P a Satisfies the following relationship:

[0015]

[0016] Where GCD(Z s ,P a ) represents the lowest common divisor of the number of stator teeth and the number of stator winding pole pairs, and k is a positive integer greater than or equal to 1.

[0017] In general, the above technical solutions conceived by the utility model can achieve the following beneficial effects compared with the prior art:

[0018] (1) The axial-radial excitation vernier permanent magnet motor provided by the utility model significantly enhances the excitation capability, improves the magnetic field density, and increases the back electromotive force and torque density by combining the first permanent magnet magnetized radially in the rotor and the second permanent magnet magnetized axially in the rotor.

[0019] (2) The rotor permanent magnet and end cover structure proposed in the utility model can simultaneously achieve the beneficial effects of enhancing the excitation of the main magnetic circuit and increasing the magnetic resistance of the leakage flux linkage, thereby greatly reducing the leakage flux of the motor permanent magnet and improving the power factor. Under the condition of the same power output, the motor inverter is smaller in size and lower in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of a traditional surface-mounted vernier permanent magnet motor;

[0021] Figure 2 It is a schematic diagram of the main magnetic circuit of a traditional surface-mounted vernier permanent magnet motor;

[0022] Figure 3 It is a schematic diagram of the leakage magnetic circuit of a traditional surface-mounted vernier permanent magnet motor;

[0023] Figure 4 A three-dimensional diagram showing the structure of an axial-radial excitation vernier permanent magnet motor provided by an embodiment of the utility model;

[0024] Figure 5 A front view of the axial-radial excitation vernier permanent magnet motor structure provided by an embodiment of the utility model;

[0025] Figure 6 A schematic diagram of the main magnetic circuit of an axial-radial excitation vernier permanent magnet motor provided by an embodiment of the utility model;

[0026] Figure 7 This is a schematic diagram of the structure of an axial-radial excitation vernier permanent magnet motor (without end covers) provided in an embodiment of the utility model.

[0027] Explanation of the reference numerals: stator core 1 , stator winding 2 , rotor first permanent magnet 31 , rotor second permanent magnet 32 ​​, rotor core 4 , end cover tooth portion 51 , end cover yoke portion 52 , rotor shaft 6 . DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the utility model and are not used to limit the utility model. In addition, the technical features involved in each embodiment of the utility model described below can be combined with each other as long as they do not conflict with each other.

[0029] like Figures 4 to 6 This is a schematic diagram of the structure of an axial-radial excitation vernier permanent magnet motor according to an embodiment of the utility model. In order to make the model clear Figure 4 Only part of the winding is shown. The motor includes a stator core 1, a stator winding 2, a rotor permanent magnet and an end cover. The rotor permanent magnet includes a rotor first permanent magnet 31 and a rotor second permanent magnet 32. The end cover includes an end cover tooth portion 51, an end cover yoke portion 52 and a rotor shaft 6. In order to improve the power factor, the rotor of the utility model has no yoke and is fixed and supported by a non-magnetic rotor shaft 6.

[0030] The stator core 1 includes a plurality of stator slots uniformly distributed along the circumference and stator teeth between two adjacent stator slots. The stator winding 2 adopts a three-phase winding, which can be centralized or distributed. The first permanent magnet 31 of the rotor is magnetized along the circumferential radial direction; the second permanent magnet 32 ​​of the rotor is magnetized along the axial direction, and the first permanent magnet 31 of the rotor and the second permanent magnet 32 ​​of the rotor are arranged alternately with N poles and S poles. The axial length of the first permanent magnet 31 of the rotor is the same as that of the stator core 1 and overlaps to reduce magnetic leakage. The second permanent magnet 32 ​​of the rotor is located on the axial outer side of the first permanent magnet 31 of the rotor, and the end cover is located on the axial outer side of the second permanent magnet 32 ​​of the rotor.

[0031] Furthermore, the first permanent magnet 31 and the second permanent magnet 32 ​​of the rotor of the present invention can be made of neodymium iron boron, samarium cobalt or ferrite. The stator core 1 and the end cover can be formed by stacking silicon steel sheets.

[0032] The end cover is a stationary part, including the end cover protruding end, i.e., the end cover tooth portion 51 and the end cover yoke portion 52. The end cover yoke portion 52 is arranged in front of the end cover tooth portion 51. The end cover is located outside the rotor second permanent magnet 32 ​​and there is an air gap therebetween. The number of teeth of the end cover tooth portion 51 is the same as the number of teeth of the stator, and the axes coincide with each other, forming an axial magnetic conduction circuit, which helps to improve the torque density.

[0033] In this embodiment, the number of teeth Z of the stator core 1 s is 6, the number of pole pairs of the first permanent magnet 31 of the rotor and the second permanent magnet of the rotor is P r is 5, the number of stator winding pole pairs P a is 1, and the number of teeth on the end cover is equal to the number of teeth on the stator, which is 6.

[0034] The number of teeth of the stator Z s , rotor permanent magnet pole pair number P r and the number of stator winding pole pairs P a Satisfies the following relationship:

[0035]

[0036] Where GCD(Z s ,P a ) represents the lowest common divisor of the number of stator teeth and the number of stator winding pole pairs, and k is a positive integer greater than or equal to 1.

[0037] The utility model benefits from the mutual cooperation between the first permanent magnet of the rotor and the second permanent magnet of the rotor, and can enhance the excitation and improve the torque density by 80%, while taking into account the advantage of the high power factor of the yokeless rotor vernier permanent magnet motor.

[0038] It is easy for those skilled in the art to understand that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An axial-radial excitation vernier permanent magnet motor, comprising a stator core, a stator winding, a rotor permanent magnet and an end cover, wherein the rotor permanent magnet comprises a rotor first permanent magnet and a rotor second permanent magnet; the end cover comprises an end cover tooth portion, an end cover yoke portion and a rotor shaft, characterized in that: The rotor shaft is a non-magnetic rotor shaft; the stator core includes stator slots uniformly distributed along the circumference and stator teeth between two adjacent stator slots; the stator winding adopts a three-phase winding, the first permanent magnet of the rotor is magnetized along the circumferential radial direction; the second permanent magnet of the rotor is magnetized along the axial direction, and the first permanent magnet of the rotor and the second permanent magnet of the rotor are both arranged alternately with N poles and S poles; the axial length of the first permanent magnet of the rotor is the same as and coincides with the stator core, the second permanent magnet of the rotor is located axially outside the first permanent magnet of the rotor, and the end cover is located axially outside the second permanent magnet of the rotor; the end cover includes an end cover tooth portion and an end cover yoke portion, the end cover yoke portion is arranged in front of the end cover tooth portion, and the end cover is located outside the second permanent magnet of the rotor and has an air gap with it; the number of teeth of the end cover tooth portion is the same as the number of teeth of the stator, and the axes coincide with each other.

2. The axial-radial excitation vernier permanent magnet motor according to claim 1, characterized in that: The number of teeth of the stator core is 6, the number of pole pairs of the first permanent magnet of the rotor and the second permanent magnet of the rotor is 5, the number of pole pairs of the stator winding is 1, and the number of teeth of the end cover is equal to the number of teeth of the stator, which is 6.

3. The axial-radial excitation vernier permanent magnet motor according to claim 1, characterized in that: Stator teeth number Z s , rotor permanent magnet pole pair number P r and the number of stator winding pole pairs P a Satisfies the following relationship: Where GCD(Z s ,P a ) represents the lowest common divisor of the number of stator teeth and the number of stator winding pole pairs, and k is a positive integer greater than or equal to 1.

4. An axial-radial excitation vernier permanent magnet motor according to claim 1 or 3, characterized in that: The stator winding is either centralized or distributed.

5. An axial-radial excitation vernier permanent magnet motor according to claim 1 or 3, characterized in that: The first permanent magnet of the rotor and the second permanent magnet of the rotor are neodymium iron boron, samarium cobalt or ferrite.

6. An axial-radial excitation vernier permanent magnet motor according to claim 1 or 3, characterized in that: The stator core and end covers are made of laminated silicon steel sheets.

7. An axial-radial excitation vernier permanent magnet motor according to claim 1 or 3, characterized in that: The stator windings are placed in the stator slots.

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