Axial auxiliary excitation non-yoke rotor vernier permanent magnet motor

Abstract

The utility model belongs to the technical field of permanent magnet motors, and relates to a vernier permanent magnet motor. The axial length of a rotor permanent magnet is the same as that of a stator iron core and coincides with that of the stator iron core, the rotor permanent magnet is radially magnetized along the circumference, N poles and S poles are alternately arranged, a rotor shaft is located in the rotor permanent magnet and coaxially rotates with the rotor permanent magnet, and the rotor shaft is used for fixing and supporting the rotor permanent magnet; the end cover permanent magnets and the end cover yoke parts are located on the two axial sides of the rotor permanent magnet, air gaps exist between the end cover permanent magnets and the rotor permanent magnet and between the end cover yoke parts and the rotor permanent magnet, the axial lengths of the end cover permanent magnets and the axial lengths of the end cover yoke parts are the same and coincide, and the number and the spatial position arrangement of the end cover permanent magnets are the same as the number and the arrangement of stator teeth of the stator iron core. According to the utility model, the excitation capability is enhanced, the magnetic field flux density is improved, and the counter electromotive force and the torque density are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of permanent magnet motors, and more specifically, relates to a vernier permanent magnet motor. Background Art

[0002] The vernier permanent magnet motor is a type of motor that works based on the magnetic field modulation effect, and its stator and rotor pole pairs are not equal. The stator uses an open slot structure for magnetic field modulation, and the stator teeth act as a pole number converter. It is worth noting that since the number of stator winding pole pairs of this type of motor is much lower than the number of rotor excitation pole pairs, the motor armature reaction is strong, the inductance is large, and the power factor is low.

[0003] Figure 1 This is a schematic diagram of the structure of a traditional yokeless rotor vernier permanent magnet motor, including a stator core, a stator winding, and a rotor permanent magnet. 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 radially magnetized, and the magnetization directions of two adjacent permanent magnets are opposite. The existing yokeless rotor vernier permanent magnet motor can greatly weaken the motor inductance and significantly improve the motor power factor by eliminating the rotor yoke. However, the torque density of the yokeless rotor vernier permanent magnet motor is low. This field urgently needs to find targeted solutions to better meet the above technical requirements faced in actual production practice. Summary of the invention

[0004] In view of the above defects or improvement needs of the prior art, the utility model provides a yokeless rotor cursor permanent magnet motor with axial auxiliary excitation, which aims to solve the technical problem of low torque density in the existing yokeless rotor cursor permanent magnet motor.

[0005] To achieve the above purpose, the utility model provides a yokeless rotor vernier permanent magnet motor with axial auxiliary excitation, which includes a stator, a stator winding, a rotor permanent magnet, a rotor shaft, an end cover yoke and an end cover permanent magnet, and the stator, the rotor and the end cover are coaxially mounted. The stator includes a stator yoke and a plurality of stator teeth; the stator winding is placed in a stator groove; the rotor permanent magnet has no rotor yoke, and the axial length is the same as and overlaps with the stator core; the rotor shaft is located inside the rotor permanent magnet, and plays the role of supporting and fixing the rotor permanent magnet; the end cover yoke and the end cover permanent magnet are stationary parts, located on both sides of the axial direction of the rotor permanent magnet, and there is an air gap between the rotor permanent magnet and the end cover yoke.

[0006] Furthermore, the stator core is formed by laminating silicon steel sheets and is a magnetic conductive material.

[0007] Furthermore, the end cover yoke is made of non-magnetic material, such as aluminum.

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

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

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

[0011] Furthermore, the end cover permanent magnets are axially magnetized, the permanent magnets located on the same side of the stator core are magnetized in the same direction, and the permanent magnets located on both sides of the stator core are magnetized in opposite directions.

[0012] Furthermore, the number of end cap permanent magnets on each side of the stator core is the same as the number of stator teeth, and the axes of the end cap permanent magnets 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 It satisfies the general working principle of the vernier permanent magnet motor, that is, 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, compared with the prior art, the above technical scheme conceived by the utility model can achieve the following beneficial effects: the yokeless rotor vernier permanent magnet motor with axial auxiliary excitation provided by the utility model significantly enhances the excitation capacity, improves the magnetic field density, and improves the back electromotive force and torque density by combining the radially magnetized permanent magnets of the rotor and the axially magnetized permanent magnets of the end cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of a traditional yokeless rotor vernier permanent magnet motor;

[0019] Figure 2 A three-dimensional diagram showing the structure of a yokeless rotor vernier permanent magnet motor with axial auxiliary excitation provided by an embodiment of the utility model;

[0020] Figure 3 A front view of the structure of a yokeless rotor vernier permanent magnet motor with axial auxiliary excitation provided by an embodiment of the utility model (excluding the end core and permanent magnet);

[0021] Figure 4A three-dimensional diagram showing the structure of a yokeless rotor vernier permanent magnet motor with axial auxiliary excitation provided by an embodiment of the utility model (excluding the end core and rotor shaft);

[0022] Figure 5 A schematic diagram of the end core and end cover permanent magnets of the yokeless rotor vernier permanent magnet motor with axial auxiliary excitation provided by an embodiment of the utility model;

[0023] Figure 6 A schematic diagram of the rotor shaft of a yokeless rotor vernier permanent magnet motor with axial auxiliary excitation provided in an embodiment of the utility model.

[0024] Description of the reference numerals: stator core 1 , stator winding 2 , rotor permanent magnet 3 , rotor shaft 4 , end cover permanent magnet 5 , end cover yoke 6 . DETAILED DESCRIPTION

[0025] 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.

[0026] Figures 2 to 4 This is a schematic diagram of the structure of a yokeless rotor vernier permanent magnet motor with axial auxiliary excitation according to an embodiment of the utility model. In order to make the model clear, Figure 3 Only part of the winding is shown. The motor of the utility model comprises a stator, a rotor and an end cover, wherein the stator comprises a stator core 1 and a stator winding 2. The rotor comprises a rotor permanent magnet 3 and a rotor shaft 4. The end cover comprises an end cover permanent magnet 5 and an end cover yoke 6.

[0027] The stator core 1 includes a plurality of stator slots evenly distributed along the circumference and stator teeth between two adjacent stator slots. The stator winding 2 adopts a three-phase AC armature winding, which can be centralized or distributed, and the stator winding 2 is arranged on the stator teeth.

[0028] The axial length of the rotor permanent magnet 3 is the same as and overlaps with the stator core 1, and its structure is consistent with that of a conventional yokeless rotor vernier permanent magnet motor. The rotor permanent magnet 3 is magnetized along the circumferential radial direction, and the N poles and S poles are arranged alternately, that is, the magnetization directions of two adjacent rotor permanent magnets 3 are opposite. The rotor shaft 4 is located inside the rotor permanent magnet 3, rotates coaxially with the rotor permanent magnet 3, and is used to fix and support the rotor permanent magnet.

[0029] The end cap permanent magnet 5 and the end cap yoke 6 are located on both sides of the axial direction of the rotor permanent magnet 3, and are both stationary parts. There is an air gap between the end cap permanent magnet 5 and the end cap yoke 6 and the rotor permanent magnet 3, and the axial lengths of the end cap permanent magnet 5 and the end cap yoke 6 are the same and overlap. The number and spatial position arrangement of the end cap permanent magnet 5 are exactly the same as the number and arrangement of the stator teeth of the stator core 1.

[0030] The rotor permanent magnet 3 and the end cover permanent magnet 5 of the utility model can be made of neodymium iron boron, samarium cobalt or ferrite.

[0031] The stator core 1 of the utility model can be formed by stacking silicon steel sheets.

[0032] The end cover yoke 6 of the present invention is made of non-magnetic material, such as aluminum.

[0033] In this embodiment, the stator core 1 has 6 teeth, the number of pole pairs of the rotor permanent magnet 3 is 5, the number of pole pairs of the stator winding 2 is 1, and 6 end cover permanent magnets 5 are provided.

[0034] The number of teeth of the stator Z s , rotor permanent magnet pole pair number P r and stator winding 2 pole pairs P a , which satisfies the general working principle of the vernier permanent magnet motor, namely the following relationship:

[0035]

[0036] Where GCD(Z s ,P a ) represents the least 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 results show that the torque density of the yokeless rotor vernier permanent magnet motor with axial auxiliary excitation according to the embodiment of the utility model can be increased by 60%, while taking into account the advantage of the high power factor of the yokeless 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. A yokeless rotor vernier permanent magnet motor with axial auxiliary excitation, comprising a stator, a rotor and an end cover, wherein the stator comprises a stator core and a stator winding; the rotor comprises a rotor permanent magnet and a rotor shaft; the end cover comprises an end cover permanent magnet and an end cover yoke, the stator core comprises stator slots uniformly distributed along the circumference and stator teeth between two adjacent stator slots, the stator winding adopts a three-phase AC armature winding, and the stator winding is arranged on the stator teeth; characterized in that: The axial length of the rotor permanent magnet is the same as and overlaps with that of the stator core, the rotor permanent magnet is magnetized radially along the circumference, and the N pole and the S pole are arranged alternately. The rotor shaft is located inside the rotor permanent magnet and rotates coaxially with the rotor permanent magnet. The rotor shaft is used to fix and support the rotor permanent magnet; the end cover permanent magnet and the end cover yoke are located on both sides of the axial direction of the rotor permanent magnet, and there is an air gap between the end cover permanent magnet and the end cover yoke and the rotor permanent magnet. The axial lengths of the end cover permanent magnet and the end cover yoke are the same and overlap, and the number and spatial position arrangement of the end cover permanent magnets are the same as the number and arrangement of stator teeth of the stator core.

2. The axial auxiliary excitation yokeless rotor vernier permanent magnet motor according to claim 1, characterized in that: The stator winding is either centralized or distributed.

3. The axial auxiliary excitation yokeless rotor vernier permanent magnet motor according to claim 1, characterized in that: The rotor permanent magnets and the end cover permanent magnets are neodymium iron boron, samarium cobalt or ferrite.

4. The axial auxiliary excitation yokeless rotor vernier permanent magnet motor according to claim 1, characterized in that: The stator core is made of laminated silicon steel sheets.

5. The axial auxiliary excitation yokeless rotor vernier permanent magnet motor according to claim 1, characterized in that: The end cover yoke is made of non-magnetic material.

6. The axial auxiliary excitation yokeless rotor vernier permanent magnet motor according to claim 1, characterized in that: The stator core has 6 teeth, the number of pole pairs of the rotor permanent magnet is 5, the number of pole pairs of the stator winding is 1, and 6 permanent magnets are arranged on the end cover.

7. The axial auxiliary excitation yokeless rotor 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 , the relationship is: 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.

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