Vernier permanent magnet motor

Abstract

This utility model discloses a vernier permanent magnet motor, including a stator assembly and a rotor assembly surrounding the stator assembly. The stator assembly includes a stator core and stator windings. The stator core includes a main shaft, a plurality of stator main teeth evenly distributed circumferentially around the main shaft, and at least two auxiliary teeth formed at the end of each stator main tooth opposite to the main shaft. The stator windings include a first coil winding wound on the stator main teeth and a second coil winding wound on the auxiliary teeth. The working magnetic field generated by the first coil winding and the second coil winding has the same phase, while the non-working magnetic field has opposite phase. The vernier permanent magnet motor of this application can simultaneously achieve high torque density and anti-saturation capability, which is beneficial for the widespread application of the motor.

Description

Technical Field

[0001] This utility model relates to the field of permanent magnet motor technology, and in particular to a vernier permanent magnet motor. Background Technology

[0002] Vernier permanent magnet motors are motors that operate based on the principle of magnetic field modulation. They feature high torque density and relatively simple structure, and have broad application prospects in fields such as electric vehicles and precision control equipment. Vernier permanent magnet motors utilize the magnetic field modulation effect to achieve energy conversion. When the stator windings are energized, a multi-pole magnetic field is generated. After modulation by a modulation ring, a specific spatial harmonic magnetic field is formed in the air gap. This harmonic magnetic field interacts with the fundamental magnetic field of the rotor permanent magnet, generating electromagnetic torque to drive the rotor to rotate. For example, when a three-phase current is applied to the stator windings to generate a 4-pole rotating magnetic field, the modulation ring can modulate it into a 10-pole harmonic. If the rotor permanent magnet is designed with 10 poles, it can synchronize with the harmonic magnetic field, achieving low-speed, high-torque output.

[0003] However, traditional vernier permanent magnet motors generate multiple non-working magnetic fields with different numbers of pole pairs. Under high electromagnetic loads, the motor is prone to saturation and has poor overload capacity, which seriously restricts the engineering application of vernier permanent magnet motors. Utility Model Content

[0004] The purpose of this invention is to provide a vernier permanent magnet motor that can simultaneously achieve high torque density and anti-saturation capability, which is beneficial for the widespread application of the motor.

[0005] To solve the above-mentioned technical problems, this utility model provides a vernier permanent magnet motor, including a stator assembly and a rotor assembly arranged around the stator assembly; the stator assembly includes a stator core and stator windings;

[0006] The stator core includes a main shaft, a plurality of stator main teeth evenly distributed around the main shaft, and at least two auxiliary teeth split at the end of each stator main tooth away from the main shaft.

[0007] The stator winding includes a first coil winding wound on the stator main teeth and a second coil winding wound on the auxiliary teeth; and the working magnetic field generated by the first coil winding and the second coil winding has the same phase, while the non-working magnetic field has the opposite phase.

[0008] In one optional embodiment of this application, the first coil winding is wound in a concentrated manner on each of the stator main teeth;

[0009] The second coil winding is distributed and wound on the auxiliary teeth.

[0010] In one optional embodiment of this application, each of the stator main teeth is provided with two auxiliary teeth at its end;

[0011] The same second coil winding is wound on the auxiliary teeth that are connected to the ends of two adjacent stator main teeth and are adjacent to each other.

[0012] In one optional embodiment of this application, each of the first coil windings and each of the second coil windings are three-phase windings;

[0013] Among them, the first coil windings with the same current phase are connected in series with each other;

[0014] The second coil windings with the same current phase in each second coil winding are connected in series;

[0015] The first coil winding and the second coil winding with the same current phase are connected in series; and the two second coil windings on the two auxiliary teeth connected to the stator main teeth of each first coil winding are not connected in series.

[0016] In one optional embodiment of this application, the number of stator main teeth in the stator assembly is an integer multiple of 3, and at least 2 times; the ratio of the number of stator main teeth to the number of rotor pole pairs in the rotor assembly is 3:5.

[0017] In one optional embodiment of this application, the number of stator main teeth in the stator assembly is 6, and the number of rotor pole pairs in the rotor assembly is 10;

[0018] Alternatively, the number of stator main teeth in the stator assembly is 9, and the number of rotor pole pairs in the rotor assembly is 15;

[0019] Alternatively, the number of stator main teeth in the stator assembly is 12, and the number of rotor pole pairs in the rotor assembly is 20;

[0020] Alternatively, the number of stator main teeth in the stator assembly is 18, and the number of rotor pole pairs in the rotor assembly is 30.

[0021] In one optional embodiment of this application, the rotor assembly includes a rotor core and a rotor permanent magnet;

[0022] The rotor permanent magnets are arranged in a Helbach array.

[0023] In one alternative embodiment of this application, the rotor permanent magnet is either surface-mounted or embedded inside the rotor core.

[0024] In an optional embodiment of this application, the inner sidewall of the rotor assembly is further provided with a reinforcing sleeve.

[0025] In one optional embodiment of this application, both the stator core and the rotor core are cores formed by axially stacking silicon steel sheets that are insulated on both sides.

[0026] The present invention provides a vernier permanent magnet motor, comprising a stator assembly and a rotor assembly surrounding the stator assembly; the stator assembly includes a stator core and a stator winding; wherein the stator core includes a main shaft, a plurality of stator main teeth evenly distributed around the main shaft, and at least two auxiliary teeth split at the end of each stator main tooth away from the main shaft; the stator winding includes a first coil winding wound on the stator main teeth and a second coil winding wound on the auxiliary teeth; and the working magnetic field generated by the first coil winding and the second coil winding has the same phase, while the non-working magnetic field has opposite phase.

[0027] The vernier permanent magnet motor of this application splits the end of the stator main teeth into at least two auxiliary teeth. In addition to a first coil winding wound on the stator main teeth, a second coil winding is wound on the auxiliary teeth. The working magnetic field generated by the first coil winding and the working magnetic field generated by the second coil winding are in phase and can be superimposed, while the non-working magnetic fields are in opposite phases and can cancel each other out. Therefore, this application utilizes split teeth as a magnetic field modulation unit to achieve the electromechanical energy conversion of multiple magnetic fields with different pole pairs. Furthermore, it simultaneously winds coils on both the stator main teeth and auxiliary teeth, and utilizes the superposition of the working magnetic fields generated by the two sets of coil windings and the mutual cancellation of the non-working magnetic fields. This significantly improves the motor's anti-saturation capability and also provides high torque density, enabling the motor to simultaneously achieve high torque density and anti-saturation capability, which is beneficial for the widespread application of the motor. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the vernier permanent magnet motor provided in the embodiments of this application;

[0030] Figure 2 A comparative schematic diagram showing the magnetomotive force corresponding to different mechanical positions in the vernier permanent magnet motor provided in the embodiments of this application;

[0031] Figure 3 A schematic diagram comparing the magnetomotive force amplitudes corresponding to different harmonic orders in the vernier permanent magnet motor provided in this application embodiment;

[0032] Figure 4 A comparative schematic diagram showing the magnetomotive force angles corresponding to different harmonic orders in the vernier permanent magnet motor provided in this application embodiment;

[0033] Figure 5 A schematic diagram comparing the magnetomotive forces of the experimental group motor and the control group motor at different mechanical positions, provided in an embodiment of this application;

[0034] Figure 6 A schematic diagram comparing the magnetomotive force amplitudes of the experimental group motor and the control group motor at different harmonic orders, provided in an embodiment of this application.

[0035] Figure 7 A schematic diagram showing the torque comparison between the experimental group motor and the control group motor as current density changes, provided for embodiments of this application;

[0036] In the attached diagram: 10 is the stator core, 11 is the main shaft, 12 is the stator main tooth, 13 is the auxiliary tooth, 14 is the first coil winding, 15 is the second coil winding, 21 is the rotor core, and 22 is the rotor permanent magnet. Detailed Implementation

[0037] The core of this invention is to provide a vernier permanent magnet motor that can simultaneously achieve high torque density and anti-saturation capability.

[0038] To enable those skilled in the art to better understand the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] like Figure 1 As shown, Figure 1 This is a schematic diagram of the structure of a vernier permanent magnet motor provided in an embodiment of this application.

[0040] In one specific embodiment of this application, the vernier permanent magnet motor may specifically include:

[0041] A stator assembly and a rotor assembly arranged around the stator assembly; the stator assembly includes a stator core 10 and stator windings;

[0042] The stator core 10 includes a main shaft 11, a plurality of stator main teeth 12 evenly distributed around the main shaft 11, and at least two auxiliary teeth 13 split at the end of each stator main tooth 12 away from the main shaft 11.

[0043] The stator winding includes a first coil winding 14 wound on the stator main teeth 12 and a second coil winding 15 wound on the auxiliary teeth 13; and the working magnetic field generated by the first coil winding 14 and the second coil winding 15 is in phase with the same phase, while the non-working magnetic field is in phase with the opposite phase.

[0044] The vernier permanent magnet motor in this embodiment is essentially a split-tooth vernier permanent magnet motor, meaning that each stator main tooth 12 has at least two auxiliary teeth 13 split at the end opposite to the main shaft; this can be referred to as the structure of a conventional split-tooth vernier permanent magnet motor, and will not be described in detail in this application. Based on this, in addition to the first coil winding 14 wound on the stator main teeth 12, the stator winding in this application further includes a second coil winding 15 wound on the auxiliary teeth 13.

[0045] In conventional split-tooth vernier permanent magnet motors, the auxiliary tooth 13 is only used to modulate the magnetic field of the stator winding, and no additional coil is wound on the auxiliary tooth 13. However, in this application, in order to improve the motor's anti-saturation capability, a first coil winding 14 and a second coil winding 15 are wound on the stator main tooth 12 and the auxiliary tooth 13, respectively. By reasonably arranging the number and layout of the stator main tooth 12 and the auxiliary tooth 13, as well as the winding method of the first coil winding 14 and the second coil winding 15, the first coil winding 14 and the second coil winding 15 can generate working magnetic fields with the same phase and non-working magnetic fields with opposite phases. This achieves the superposition and enhancement of the working magnetic fields of the first coil winding 14 and the second coil winding 15, while the non-working magnetic fields cancel each other out. That is, on the one hand, high torque density can be improved, and on the other hand, the motor's anti-saturation capability can be improved.

[0046] like Figure 1 As shown, in an optional embodiment of this application, the first coil windings 14 on the stator main teeth 12 are centrally distributed, that is, a set of first coil windings 14 is centrally wound on each stator main tooth 12, while the second coil windings 15 on the auxiliary teeth 13 are distributed. Taking the example that each stator main tooth 12 has only two auxiliary teeth 13 at its end, the same set of second coil windings 15 can be wound on the two adjacent auxiliary teeth 13 connected to the ends of two adjacent stator main teeth 12. At this time, although the second coil windings 15 on the auxiliary teeth 13 are distributed, since the area corresponding to the main tooth slots between two adjacent stator main teeth 12 is empty, it is ensured that the second coil windings 15 do not interfere with each other, thus facilitating winding, and the auxiliary teeth 13 are relatively short.

[0047] Furthermore, in this embodiment, the current flowing through the first coil winding 14 and the second coil winding 15 can both be three-phase electricity. That is, for each first coil winding 14, the current flowing through it should be 120° ahead of the current phase in the adjacent first coil winding 14 on one side, and 120° behind the current phase in the first coil winding 14 on the other side. Similarly, the current phases between adjacent second coil windings 15 also differ by 120°.

[0048] In practical applications, the first coil windings 14 with the same current phase can be connected in series with each other. Generally, the two first coil windings 14 with a gap of two first coil windings 14 in the middle are connected in series. Similarly, the second coil windings 15 with the same current phase can also be connected in series with each other. That is, the two second coil windings 15 with a gap of two second coil windings 15 in the middle are also connected in series.

[0049] In addition, the first coil winding 14 and the second coil winding 15, which have the same current phase, can also be connected in series.

[0050] However, it should be noted that in this embodiment, the current phase in the first coil winding 14 wound on each stator main tooth 12 should be 120° ahead and 120° behind the current phase of the two second coil windings 15 wound on the two auxiliary teeth 13 connected to the stator main tooth 12, respectively.

[0051] Therefore, the two second coil windings 15 on the two auxiliary teeth 13 connected to each first coil winding 14 and its corresponding stator main tooth 12 are not connected in series. Generally, among the first coil windings 14 and second coil windings 15 connected in series, the closest first coil winding 14 and second coil winding 15 should satisfy the following condition: the stator main tooth 12 wound by the first coil winding 14 should be adjacent to the stator main tooth 12 connected to the auxiliary tooth 13 wound by the second coil winding 15.

[0052] Based on any of the above embodiments, in an optional embodiment of this application, the vernier permanent magnet motor may further include a stator assembly in which the number of stator main teeth 12 is an integer multiple of 3 and at least 2 times; the ratio of the number of stator main teeth 12 to the number of rotor pole pairs in the rotor assembly is 3:5.

[0053] When the ratio of the number of stator main teeth 12 to the number of rotor pole pairs of the rotor assembly is 3:5, according to the principle of magnetic field modulation, and when both the first coil winding 14 and the second coil winding 15 are three-phase windings, the working harmonics are in the same phase and the non-working harmonics are in opposite phases. At this time, the non-working harmonics can cancel each other out, which greatly enhances the anti-saturation performance of the motor.

[0054] Furthermore, in practical applications, the number of stator main teeth 12 in the stator assembly can be 6, and the number of rotor pole pairs in the rotor assembly is 10.

[0055] Alternatively, the number of stator main teeth 12 in the stator assembly can be 9, and the number of rotor pole pairs in the rotor assembly can be 15;

[0056] Alternatively, the number of stator main teeth 12 in the stator assembly can be 12, and the number of rotor pole pairs in the rotor assembly can be 20;

[0057] Alternatively, the number of stator main teeth 12 in the stator assembly can be 18, and the number of rotor pole pairs in the rotor assembly can be 30.

[0058] In this embodiment, the operating harmonics and non-operating harmonics of the vernier permanent magnet motor and the conventional motor are the same. When the number of stator main teeth 12 of the vernier permanent magnet motor in this embodiment is 6 and the number of rotor pole pairs is 10, the main operating harmonics are 2, 10, and 14, and the main non-operating harmonics are 4, 8, and 16.

[0059] like Figure 2 , Figure 3 and Figure 4 As shown, Figure 2 The diagram shows a comparison of the magnetomotive forces corresponding to different mechanical positions of the rotor assembly when three-phase power is applied to the first coil winding 14 and the second coil winding 15 respectively. Figure 3 The diagram shows a comparison of the magnetomotive force amplitudes corresponding to different harmonic orders when three-phase electricity is applied to the first coil winding 14 and the second coil winding 15 respectively. Figure 4 The diagram shows a comparison of the magnetomotive force angles corresponding to different harmonic orders when three-phase electricity is applied to the first coil winding 14 and the second coil winding 15, respectively. According to... Figures 2 to 4 It can be seen that in this embodiment, when the number of stator main teeth 12 of the vernier permanent magnet motor is 6 and the number of rotor pole pairs is 10, the working magnetomotive forces with working harmonics of 2, 10, and 14 have the same phase and are superimposed on each other, while the non-working magnetomotive forces with non-working harmonics of 4 and 8 have opposite phases and cancel each other out.

[0060] like Figure 5 and Figure 6 As shown, Figure 5 and Figure 6 In this embodiment, the vernier permanent magnet motor is used as the experimental group motor, and the conventional motor is used as the control group motor. Under the conditions that both the experimental and control group motors have 6 stator main teeth (12) and 10 rotor pole pairs, the armature magnetomotive force waveforms and their Fourier analysis results are compared under the same electrical load. Figure 5 and Figure 6It can be seen that the experimental group motor in this application has a slightly higher working magnetomotive force amplitude than the control group motor when the harmonic order is 2, 10 and 14, while the non-working magnetomotive force amplitude is significantly lower when the harmonic order is 4 and 8.

[0061] like Figure 7 As shown, Figure 7 In this embodiment, the vernier permanent magnet motor is used as the experimental group motor, and the conventional motor is used as the control group motor. Under the condition that both the experimental and control group motors have 6 stator main teeth (12) and 10 rotor pole pairs, the torque output capabilities of the two motors are compared. Figure 7 It can be seen that as the current density increases, the control group motor quickly saturates, while the experimental group motor's anti-saturation capability is greatly improved.

[0062] In summary, the vernier permanent magnet motor of this application splits the end of the stator main tooth 12 into at least two auxiliary teeth 13. In addition to a first coil winding 14 wound on the stator main tooth 12, a second coil winding 15 is wound on the auxiliary teeth 13. The working magnetic field generated by the first coil winding 14 and the working magnetic field generated by the second coil winding 15 are in phase and can be superimposed, while the non-working magnetic fields are in opposite phases and can cancel each other out. Therefore, this application utilizes split teeth as a magnetic field modulation unit to achieve the electromechanical energy conversion of multiple magnetic fields with different pole pairs. Furthermore, it simultaneously winds coils on the stator main tooth 12 and auxiliary teeth 13, and utilizes the superposition of the working magnetic fields generated by the two sets of coils and the mutual cancellation of the non-working magnetic fields, greatly improving the motor's anti-saturation capability while possessing high torque density. This allows the motor to simultaneously achieve high torque density and anti-saturation capability, which is beneficial for the widespread application of the motor.

[0063] Based on any of the above embodiments, in order to further improve the anti-saturation capability of the vernier permanent magnet motor, the rotor permanent magnets 22 in the rotor assembly can be further arranged in a Hellbuck array.

[0064] Alternatively, the rotor permanent magnet 22 may be surface-mounted or embedded inside the rotor core 21 in the rotor assembly.

[0065] In addition, in order to ensure the stability of the rotor assembly structure, in another optional embodiment of this application, an annular reinforcing sleeve can be provided on the inner sidewall of the rotor assembly, which can strengthen the tightness of the connection between the rotor permanent magnet 22 and the rotor core 21 to a certain extent.

[0066] Furthermore, in this application, both the stator core 10 in the stator assembly and the rotor core 21 in the rotor assembly can be cores formed by axially stacking silicon steel sheets that are insulated on both sides.

[0067] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that the elements inherent in a process, method, article, or apparatus that includes a list of elements are included. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. Additionally, portions of the technical solutions provided in the embodiments of this application that are consistent with the implementation principles of corresponding technical solutions in the prior art have not been described in detail to avoid excessive elaboration.

[0068] This article uses specific examples to illustrate the principles and implementation methods of this utility model. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made to this utility model without departing from the principles of this utility model, and these improvements and modifications also fall within the protection scope of this utility model.

Claims

1. A vernier permanent magnet motor, characterized in that, It includes a stator assembly and a rotor assembly disposed around the stator assembly; the stator assembly includes a stator core and stator windings; The stator core includes a main shaft, a plurality of stator main teeth evenly distributed around the main shaft, and at least two auxiliary teeth split at the end of each stator main tooth away from the main shaft. The stator winding includes a first coil winding wound on the stator main teeth and a second coil winding wound on the auxiliary teeth; and the working magnetic field generated by the first coil winding and the second coil winding has the same phase, while the non-working magnetic field has the opposite phase.

2. The vernier permanent magnet motor as described in claim 1, characterized in that, The first coil winding is wound in a concentrated manner on each of the stator main teeth; The second coil winding is distributed and wound on the auxiliary teeth.

3. The vernier permanent magnet motor as described in claim 2, characterized in that, Each of the stator main teeth is provided with two auxiliary teeth at its end; The same second coil winding is wound on the auxiliary teeth that are connected to the ends of two adjacent stator main teeth and are adjacent to each other.

4. The vernier permanent magnet motor as described in claim 3, characterized in that, Each of the first coil windings and each of the second coil windings are three-phase windings; Among them, the first coil windings with the same current phase are connected in series with each other; The second coil windings with the same current phase in each second coil winding are connected in series; The first coil winding and the second coil winding with the same current phase are connected in series; and the two second coil windings on the two auxiliary teeth connected to the stator main teeth of each first coil winding are not connected in series.

5. The vernier permanent magnet motor as described in claim 4, characterized in that, The number of stator main teeth in the stator assembly is an integer multiple of 3, and at least 2; the ratio of the number of stator main teeth to the number of rotor pole pairs in the rotor assembly is 3:

5.

6. The vernier permanent magnet motor as described in claim 5, characterized in that, The number of stator main teeth in the stator assembly is 6, and the number of rotor pole pairs in the rotor assembly is 10. Alternatively, the number of stator main teeth in the stator assembly is 9, and the number of rotor pole pairs in the rotor assembly is 15; Alternatively, the number of stator main teeth in the stator assembly is 12, and the number of rotor pole pairs in the rotor assembly is 20; Alternatively, the number of stator main teeth in the stator assembly is 18, and the number of rotor pole pairs in the rotor assembly is 30.

7. The vernier permanent magnet motor as described in any one of claims 1 to 6, characterized in that, The rotor assembly includes a rotor core and a rotor permanent magnet; The rotor permanent magnets are arranged in a Helbach array.

8. The vernier permanent magnet motor as described in claim 7, characterized in that, The rotor permanent magnet is either surface-mounted or built-in on the inner side of the rotor core.

9. The vernier permanent magnet motor as described in claim 8, characterized in that, The inner wall of the rotor assembly is also provided with a reinforcing sleeve.

10. The vernier permanent magnet motor as described in claim 7, characterized in that, Both the stator core and the rotor core are formed by axially stacking silicon steel sheets that are insulated on both sides.

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