Rotor structure and motor

Abstract

A rotor structure (100), comprising: a rotor iron core (1); and a plurality of first magnetic pole assemblies (2), wherein the plurality of first magnetic pole assemblies (2) are arranged at intervals along the circumferential direction of the rotor iron core (1), each first magnetic pole assembly comprises a first magnetic steel slot (21) and a second magnetic steel slot (22), each first magnetic steel slot (21) comprises a symmetric section (211) and an asymmetric section (212) that are connected to each other, the symmetric section (211) and the second magnetic steel slot (22) are symmetrically arranged, and the asymmetric section (212) extends along the circumferential direction of the rotor iron core (1).

Description

Rotor structure and motor

[0001] Related applications

[0002] The present application claims priority to Chinese Patent Application No. 202410625765.8, filed on May 20, 2024, the contents of which are incorporated herein by reference in their entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of electric machines, and in particular to a rotor structure and a motor. BACKGROUND

[0004] High-speed built-in permanent magnet synchronous motors are highly regarded in new energy vehicle electric drive systems due to a series of advantages such as high power density, high operating efficiency, and wide speed regulation range. The motor requires high power density, large peak torque, high efficiency, high speed, and wide speed range.

[0005] In related technologies, it is difficult to improve the electric torque by using a symmetric rotor structure while the amount of magnetic steel and the basic topology structure remain unchanged. However, using an asymmetric rotor structure increases the harmonic content of the motor, which induces a harmonic electromotive force in the motor winding, generates a harmonic current, and worsens the motor vibration and noise problems. SUMMARY

[0006] The main purpose of the present application is to provide a rotor structure and a motor, which aims to at least solve the motor vibration and noise problems caused by the asymmetric rotor structure of the motor in related technologies.

[0007] To achieve the above-mentioned purpose, the present application provides a rotor structure, which comprises:

[0008] A rotor core;

[0009] A plurality of first magnetic pole assemblies, the plurality of first magnetic pole assemblies are arranged at intervals along the circumference of the rotor core, each first magnetic pole assembly comprises a first magnetic steel slot and a second magnetic steel slot, the first magnetic steel slot comprises a symmetric section and an asymmetric section connected in series, the symmetric section is symmetrically arranged with the second magnetic steel slot, and the asymmetric section extends along the circumference of the rotor core.

[0010] In the technical solution of the present application, by extending the asymmetric section along the circumference of the rotor core and asymmetrically arranging the first magnetic steel slot and the second magnetic steel slot, the harmonic amplitude affecting the motor performance is effectively weakened, thereby reducing the spatial harmonics of the air gap magnetic field, reducing the motor main order radial electromagnetic force, and improving the motor NVH performance.

[0011] In an embodiment, the two side walls of the asymmetric section in the radial direction of the rotor core are arc-shaped.

[0012] In the technical scheme of the embodiment, the arc-shaped arrangement of the asymmetric section improves the uniformity of the rotor structure magnetic field, and is beneficial to improving the NVH performance of the motor.

[0013] In an embodiment, the distance between the asymmetric section and the two side walls in the radial direction of the rotor core is h1, and 2mm≤h1≤3.5mm.

[0014] In the technical scheme of the embodiment, the size of the asymmetric section has little effect on the motor torque, while the NVH performance of the motor can be significantly improved.

[0015] In an embodiment, the side wall of the asymmetric section away from the symmetric section is connected to at least one of the two side walls in the radial direction of the rotor core through a round corner.

[0016] In the technical scheme of the embodiment, the structure of the asymmetric section reduces the instability of the rotor structure in operation caused by stress concentration.

[0017] In an embodiment, the rotor structure further comprises a plurality of second magnetic pole assemblies arranged at intervals in the circumferential direction of the rotor core, and the plurality of second magnetic pole assemblies are arranged correspondingly to the plurality of first magnetic pole assemblies, and each second magnetic pole assembly is located on one side of the corresponding first magnetic pole assembly in the radial direction of the rotor core.

[0018] In the technical scheme of the embodiment, the arrangement of the double-layer magnetic poles is beneficial to further improving the stability of the rotor structure in operation, reducing noise, and improving the NVH performance.

[0019] In an embodiment, the second magnetic pole assembly is located on the side of the corresponding first magnetic pole assembly close to the rotor shaft center of the rotor core.

[0020] In the technical scheme of the embodiment, for the arrangement of the double-layer magnetic poles of the rotor structure, the magnetic pole with the asymmetric section is arranged on the outer side, the asymmetric magnetic pole causes the rotor magnetic field to deviate, and the second magnetic pole assembly has a combined effect, which has a good inhibitory effect on the radial electromagnetic force generated between the stator and the rotor, thereby improving the NVH performance of the motor.

[0021] In an embodiment, the second magnetic steel slot is arranged at an angle with the symmetric section.

[0022] Each second magnetic pole assembly comprises two symmetrically arranged third magnetic steel slots, and the two third magnetic steel slots are arranged at an angle.

[0023] In the technical scheme of the embodiment, the rotor structure is arranged in a double-V shape, which improves the overall efficiency and output power of the motor, improves the dynamic performance, makes the motor more stable at high speed, and reduces the noise and vibration during operation of the motor, thereby improving the NVH performance.

[0024] In an embodiment, a side wall of the asymmetric section away from the symmetric section is arranged in parallel with a side wall of the third magnetic steel slot in the rotor core in the radial direction.

[0025] In the technical scheme of the embodiment, the relative arrangement of the asymmetric section and the third magnetic steel slot improves the uniformity of the magnetic field distribution of the rotor structure.

[0026] In an embodiment, the distance between the side wall of the asymmetric section away from the symmetric section and the third magnetic steel slot is h2, and 2mm≤h2≤4mm.

[0027] In the technical scheme of the embodiment, the size between the asymmetric section and the third magnetic steel slot is set to reduce the magnetic leakage while ensuring the strength of the rotor structure.

[0028] The application also provides a motor, which comprises a stator and a rotor structure arranged in rotation in the stator, and the rotor structure comprises:

[0029] a rotor core;

[0030] a plurality of first magnetic pole assemblies, the plurality of first magnetic pole assemblies are arranged at intervals in the circumferential direction of the rotor core, each first magnetic pole assembly comprises a first magnetic steel slot and a second magnetic steel slot, the first magnetic steel slot comprises a symmetric section and an asymmetric section connected in series, the symmetric section is arranged symmetrically with the second magnetic steel slot, and the asymmetric section extends in the circumferential direction of the rotor core.

[0031] In the technical scheme of the application, the plurality of first magnetic pole assemblies are arranged at intervals in the circumferential direction of the rotor core, each first magnetic pole assembly comprises a first magnetic steel slot and a second magnetic steel slot, the first magnetic steel slot comprises a symmetric section and an asymmetric section connected in series, and the symmetric section is arranged symmetrically with the second magnetic steel slot, i.e., the first magnetic steel slot and the second magnetic steel slot are arranged asymmetrically as a whole, according to the magnetic field offset effect, the motor can improve the peak torque by reducing the permanent magnet torque and the magnetic resistance torque peak point electric angle, and the asymmetric section extends in the circumferential direction of the rotor core, effectively weakening the harmonic amplitude affecting the performance of the motor, thereby reducing the spatial harmonic of the air gap magnetic field, reducing the radial electromagnetic force of the motor, and improving the NVH performance of the motor. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only represent some of the embodiments of the present application, and all other drawings obtained by those of ordinary skill in the art without creative effort based on these drawings also belong to the protection scope of the present application.

[0033] Fig. 1 is a structural schematic diagram of an embodiment of the motor provided by the present application;

[0034] Fig. 2 is a partial structural schematic diagram of the rotor structure in Fig. 1;

[0035] Fig. 3 is a schematic diagram of the torque and current lead angle of the motor provided by the present application;

[0036] Fig. 4 is a schematic diagram of the torque characteristic of the motor provided by the present application;

[0037] Fig. 5 is a schematic diagram of the torque and current lead angle of the motor with a symmetrical rotor structure in the related art.

[0038] Explanation of reference signs:

[0039] 100, rotor structure; 1, rotor core; 2, first magnetic pole assembly; 21, first magnetic steel slot; 211, symmetrical section; 212, asymmetrical section; 22, second magnetic steel slot; 23, first magnetic steel; 3, second magnetic pole assembly; 31, third magnetic steel slot; 32, second magnetic steel; 4, stator.

[0040] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the protection scope of the present application.

[0042] It should be noted that if the directionality indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of the present application, the directionality indication is only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directionality indication also changes accordingly.

[0043] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first" and "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0044] High-speed built-in permanent magnet synchronous motor is highly regarded in new energy vehicle electric drive system due to a series of advantages such as high power density, high working efficiency and wide speed regulation range. The motor requires high power density, large peak torque, high efficiency, high speed and wide range.

[0045] In the related art, it is difficult to improve the electric torque by using a symmetric rotor structure under the condition that the amount of magnetic steel is unchanged and the basic topology is the same. However, by using an asymmetric rotor structure, the harmonic content of the motor increases, and a harmonic electromotive force is induced in the motor winding, which generates a harmonic current and worsens the motor vibration and noise problems.

[0046] The present application provides a rotor structure and a motor, which aims to at least solve the motor vibration and noise problems caused by the asymmetric rotor structure of the motor in the related art.

[0047] Please refer to FIG. 1 and FIG. 2, in an embodiment of the present application, the rotor structure 100 includes a rotor core 1 and a plurality of first magnetic pole assemblies 2, a plurality of the first magnetic pole assemblies 2 are arranged at intervals along the circumference of the rotor core 1, each of the magnetic pole assemblies includes a first magnetic steel slot 21 and a second magnetic steel slot 22, the first magnetic steel slot 21 includes a symmetric section 211 and an asymmetric section 212 connected in series, the symmetric section 211 is symmetrically arranged with the second magnetic steel slot 22, and the asymmetric section 212 extends along the circumference of the rotor core 1.

[0048] In the technical solution of the application, the first magnetic pole assemblies 2 are arranged at intervals along the circumference of the rotor core 1, each first magnetic pole assembly 2 comprises a first magnetic steel slot 21 and a second magnetic steel slot 22, the first magnetic steel slot 21 comprises a symmetric section 211 and an asymmetric section 212 connected to each other, and the symmetric section 211 is symmetrically arranged with the second magnetic steel slot 22, that is, the first magnetic steel slot 21 and the second magnetic steel slot 22 are asymmetrically arranged as a whole, according to the magnetic field offset effect, the motor can improve the peak torque by reducing the permanent magnet torque and the magnetic resistance torque peak point electric angle, and the asymmetric section 212 extends along the circumference of the rotor core 1, effectively weakening the harmonic amplitude affecting the motor performance, thereby reducing the spatial harmonic of the air gap magnetic field, reducing the motor main order radial electromagnetic force, and improving the motor NVH performance.

[0049] The first magnetic pole assembly 2 further comprises two first magnetic steels 23, and the two first magnetic steels 23 are arranged in the symmetric section 211 and the second magnetic steel slot 22. Specifically, in order to make the magnetic flux generated by the stator 4 concentrate on the first magnetic steel 23, thereby reducing the radial adsorption force of the magnetic flux generated by the stator 4 on the first magnetic steel 23, the first magnetic steel 23 is preferably a neodymium iron boron magnet in this embodiment.

[0050] The design changes the overall magnetic circuit by changing the structure of the first magnetic steel slot 21, without changing the structure of the magnetic steel, so as to improve the torque density while reducing the motor main order radial electromagnetic force and improving the motor NVH performance under the same material cost.

[0051] The asymmetric section 212 can be linear or arc-shaped. In the embodiment of the application, the two side walls of the asymmetric section 212 in the radial direction of the rotor core 1 are arc-shaped, that is, the asymmetric section 212 is arc-shaped as a whole. Compared with the linear arrangement, the arc-shaped asymmetric section 212 makes the magnetic field of the overall rotor structure 100 more uniform during operation, and is beneficial to improving the NVH performance of the motor.

[0052] Further, in order to make the width of the asymmetric section 212 uniform at different positions, so as to ensure the uniformity of the magnetic field, in the embodiment of the application, the two side walls of the asymmetric section 212 in the radial direction of the rotor core 1 are concentrically arranged, so that the width of the arc-shaped asymmetric section 212 is uniform at different positions.

[0053] The width of the asymmetric section 212 should not be too large, otherwise it will have a greater impact on the magnetic field of the rotor structure 100, which will in turn result in lower motor torque. Of course, the width of the asymmetric section 212 should not be too small, otherwise the effect of reducing the motor main order radial electromagnetic force will not be obvious, and the NVH performance will not be significantly improved. In summary, in the embodiments of the present application, please refer to FIG. 2, the distance between the asymmetric section 212 and the two side walls in the radial direction of the rotor core 1 is h1, 2mm≤h1≤3.5mm, h1 in this size range, the NVH performance is significantly improved while the impact on the motor torque is small, h1 can be 2mm, 3mm, 3.5mm.

[0054] The structure of the first magnetic pole assembly 2 can be various, such as V-shaped, U-shaped, and linear, etc. In the embodiments of the present application, the second magnetic steel slot 22 is arranged at an angle with the symmetric section 211, and two first magnetic steels 23 are arranged behind the symmetric section 211 and the second magnetic steel slot 22, respectively. The overall rotor structure 100 is in a V-shaped structure. Compared with U-shaped, linear, etc., the torque and efficiency of the V-shaped motor are higher, and noise and vibration are less likely to occur during high-speed operation, which is beneficial to further improve the NVH performance.

[0055] In order to reduce the phenomenon of stress concentration and thus affect the NVH performance of the rotor structure 100 during operation, in the embodiments of the present application, please refer to FIG. 2, the side wall of the asymmetric section 212 away from the symmetric section 211 is connected to at least one of the two side walls in the radial direction of the rotor core 1 by a round corner. The connection through the round corner can effectively reduce the phenomenon of stress concentration and reduce noise. The side wall of the asymmetric section 212 in the radial direction of the rotor core 1 can be one of the side walls connected to the side wall of the asymmetric section 212 away from the symmetric section 211 by a round corner, or both of the side walls can be connected to the side wall of the asymmetric section 212 away from the symmetric section 211 by a round corner. In the embodiments of the present application, it is preferred that both of the side walls are connected to the side wall of the asymmetric section 212 away from the symmetric section 211 by a round corner.

[0056] The rotor structure 100 can be a single-layer magnetic pole or a multi-layer magnetic pole. In the embodiment of the present application, referring to FIGS. 1 and 2, the rotor structure 100 further comprises a plurality of second magnetic pole assemblies 3 arranged along the circumference of the rotor core 1, and the plurality of second magnetic pole assemblies 3 are arranged correspondingly to the plurality of first magnetic pole assemblies 2, and each second magnetic pole assembly 3 is located on one side of the corresponding first magnetic pole assembly 2 in the radial direction of the rotor core 1. In the technical solution of the embodiment, when a double-layer magnetic pole motor is used in actual use, the torque characteristics are smoother, the noise during starting and acceleration is relatively smaller, and the NVH performance is improved. However, when the motor is operated under high load, the torque characteristics of the single-layer magnetic pole are more superior. Under the rated output power, the efficiency of the double-layer magnetic pole is higher, while under low load, the efficiency of the single-layer magnetic pole is higher. The stator core 4 of the double-layer magnetic pole is thicker and more durable, while the stator core 4 of the single-layer magnetic pole is simple in structure and is more susceptible to magnetic field loss.

[0057] The first magnetic pole assembly 2 can have various structural forms, such as V-shaped, U-shaped, and linear, and the second magnetic pole assembly 3 can also have various structural forms, such as V-shaped, U-shaped, and linear. The first magnetic pole assembly 2 and the second magnetic pole assembly 3 can have different structural forms, one of which is V-shaped, or both of which are V-shaped.

[0058] Specifically, in the embodiment of the present application, the second magnetic steel slot 22 is arranged at an angle with the symmetric segment 211; each second magnetic pole assembly 3 comprises two third magnetic steel slots 31 arranged symmetrically, and the two third magnetic steel slots 31 are arranged at an angle. In this way, the first magnetic pole assembly 2 and the second magnetic pole assembly 3 are both V-shaped, and the overall rotor structure 100 has a double-V-shaped topology, which can make the current in the rotor structure 100 more evenly distributed, reduce the current density gradient, thereby reducing damage and improving the overall efficiency of the motor; can make the magnetic flux of the rotor structure 100 more concentrated, improve the utilization rate of the magnetic flux, and thus improve the output power of the motor; can also improve the dynamic performance of the motor, making the motor more stable at high speed, thereby reducing the noise and vibration during motor operation and improving the NVH performance.

[0059] The second magnetic pole assembly 3 further comprises two second magnetic steels 32, and the two second magnetic steels 32 are arranged in the two third magnetic steel slots 31. The second magnetic steel 32 is generally a magnet made of neodymium iron boron, aluminum nickel cobalt, ferrite, or other permanent magnetic materials. Specifically, in order to make the magnetic flux generated by the stator 4 concentrate on the second magnetic steel 32 to reduce the radial adsorption force of the magnetic flux generated by the stator 4 on the second magnetic steel 32, the second magnetic steel 32 in the embodiment is preferably a neodymium iron boron magnet.

[0060] The second magnetic pole assembly 3 can be located on the side of the first magnetic pole assembly 2 close to the rotor shaft center, or on the side of the first magnetic pole assembly 2 away from the rotor shaft center, and in order to further reduce the radial electromagnetic force of the motor, in the embodiment of the present application, the second magnetic pole assembly 3 is located on the side of the first magnetic pole assembly 2 close to the rotor shaft center of the rotor core 1. In this way, the first magnetic pole assembly 2 is closer to the stator 4, so that the asymmetric section 212 of the first magnetic pole assembly 2 can cause the rotor magnetic field to deviate, and the second magnetic pole assembly 3 works together to better suppress the radial electromagnetic force generated between the stator 4 and the rotor, thereby improving the NVH performance of the motor.

[0061] Further, the above-mentioned asymmetric section 212 can be linearly arranged or arcuately arranged, and in the embodiment, the asymmetric section 212 is preferably arcuately arranged. When the width of the asymmetric section 212 is constant, the area of the arcuately arranged asymmetric section 212 is larger, and the suppression effect is better.

[0062] In order to improve the uniformity of the magnetic field distribution of the rotor structure 100, in the embodiment of the present application, the side wall of the asymmetric section 212 away from the symmetric section 211 is parallel to the side wall of the third magnetic steel slot 31 adjacent to the rotor core 1 in the radial direction; in this way, the uniformity of the thickness of the rotor core 1 between the asymmetric section 212 and the third magnetic steel slot 31 is ensured as much as possible, the uniformity of the magnetic field distribution is improved, and the stability is further improved, which is beneficial to improve the NVH performance.

[0063] The distance between the side wall of the asymmetric section 212 away from the symmetric section 211 and the third magnetic steel slot 31 adjacent to the rotor core 1 is h2, h2 should not be too large or too small, h2 being too large will cause the motor to have increased magnetic leakage, and the electromagnetic performance will correspondingly decrease; h2 being too small will cause the overall rotor structure 100 to have low strength, and when the motor rotates at high speed, it is easy to deform, so in the embodiment of the present application, 2mm≤h2≤4mm, for example, h2 can be 2mm, 3mm or 4mm, which reduces the magnetic leakage while ensuring the strength of the rotor structure 100.

[0064] In an embodiment, referring to FIGS. 1-2, the rotor structure 100 comprises a rotor core 1 and a plurality of first magnetic pole assemblies 2 spaced along the circumference of the rotor core 1, each of the first magnetic pole assemblies 2 comprising a first magnetic steel slot 21 and a second magnetic steel slot 22, the first magnetic steel slot 21 comprising a symmetric section 211 and an asymmetric section 212 connected to each other, the symmetric section 211 being symmetrically arranged with the second magnetic steel slot 22, and the asymmetric section 212 extending along the circumference of the rotor core 1; in some embodiments, the two side walls of the asymmetric section 212 in the radial direction of the rotor core 1 are arranged in an arc shape; in some embodiments, the side wall of the asymmetric section 212 away from the symmetric section 211 is connected to at least one of the two side walls in the radial direction of the rotor core 1 by a rounded corner; in some embodiments, the distance between the two side walls of the asymmetric section 212 in the radial direction of the rotor core 1 is h1, and 2mm≤h1≤3.5mm; in some embodiments, the rotor structure 100 further comprises a plurality of second magnetic pole assemblies 3 spaced along the circumference of the rotor core 1, the plurality of second magnetic pole assemblies 3 being arranged correspondingly to the plurality of first magnetic pole assemblies 2, each of the second magnetic pole assemblies 3 being located on one side of the corresponding first magnetic pole assembly 2 in the radial direction of the rotor core 1; in some embodiments, the second magnetic pole assembly 3 is located on the side of the corresponding first magnetic pole assembly 2 close to the rotor shaft center of the rotor core 1; in some embodiments, the second magnetic steel slot 22 is arranged at an angle with the symmetric section 211; each of the second magnetic pole assemblies 3 comprises two third magnetic steel slots 31 arranged symmetrically, and the two third magnetic steel slots 31 are arranged at an angle; in some embodiments, the side wall of the asymmetric section 212 away from the symmetric section 211 is arranged in parallel with the side wall of the adjacent third magnetic steel slot 31 in the radial direction of the rotor core 1; in some embodiments, the distance between the side wall of the asymmetric section 212 away from the symmetric section 211 and the adjacent third magnetic steel slot 31 is h2, and 2mm≤h2≤4mm.

[0065] In the technical scheme of the embodiment, the first magnetic pole assemblies 2 are arranged at intervals along the circumference of the rotor core 1, each first magnetic pole assembly 2 comprises a first magnetic steel slot 21 and a second magnetic steel slot 22, the first magnetic steel slot 21 comprises a symmetric segment 211 and an asymmetric segment 212 connected in sequence, and the symmetric segment 211 is symmetrically arranged with the second magnetic steel slot 22, that is, the first magnetic steel slot 21 and the second magnetic steel slot 22 are asymmetrically arranged as a whole, according to the magnetic field offset effect, so that the motor can improve the peak torque by reducing the electric angle of the peak points of the permanent magnet torque and the reluctance torque, and the asymmetric segment 212 extends along the circumference of the rotor core 1, so that different induced voltages are generated between the adjacent two segments of the core during the operation of the rotor, the main order radial electromagnetic force of the motor is reduced, the harmonic amplitude affecting the performance of the motor is effectively weakened, and then the spatial harmonics of the air gap magnetic field are reduced, and the NVH performance of the motor is improved; meanwhile, the overall topology structure adopts a double-V type structure, in the actual working process of the rotor structure 100, the output power is large and the operation is stable, and the asymmetric segment 212 is arranged at the periphery of the second magnetic pole assembly 3, the asymmetric segment 212 causes the rotor magnetic field to be offset, and cooperates with the second magnetic pole assembly 3 to have a good inhibitory effect on the radial electromagnetic force generated between the stator 4 and the rotor, thereby improving the NVH performance of the motor, and the embodiment changes the structure of the magnetic steel slot without changing the amount of magnetic steel, so that the torque density is improved under the condition that the amount of magnetic steel is unchanged, the main order radial electromagnetic force of the motor is reduced, the NVH performance of the motor is improved, and the cost is saved.

[0066] Please refer to FIG. 3 and FIG. 5, FIG. 3 is a schematic diagram of motor torque and current lead angle of the embodiment, and FIG. 5 is a schematic diagram of motor torque and current lead angle of the symmetric rotor structure in the related art, the motor torque comprises permanent magnet torque and reluctance torque, the permanent magnet torque and the reluctance torque peak point electric angle of the traditional built-in permanent magnet synchronous motor differ by 45°, and the total torque is as follows: T all = T pm cos(β) + T r sin(2β)

[0067] In the embodiment, the total torque is as follows: T all = T pm cos(β-α s ) + T r sin(2β)

[0068] In the above formula, Tpmis a permanent magnet torque peak value, Tpmis a reluctance torque peak value, is a magnetic field offset angle, and is a current lead angle. The present embodiment improves the peak torque by reducing the permanent magnet torque and the reluctance torque peak point electric angle by using the magnetic field offset effect, and improves the torque density under the same material cost. Referring to FIG. 4, which is a schematic diagram of the motor torque characteristics in the present embodiment, the rotor structure 100 in the present embodiment is applied to the motor, and the peak torque of the motor is obviously improved.

[0069] Please continue to refer to the following table, which is a comparison data table of the main order radial electromagnetic force of the rotor structure 100 applied to the motor in the present embodiment and the conventional symmetric structure in the related art.

[0070] It can be seen that the 48th order radial force density is reduced by about 24%, and the motor NVH performance is greatly improved.

[0071] The present application also proposes a motor, which comprises a stator and a rotor structure 100. The specific structure of the rotor structure 100 is referred to the above embodiments. Since the motor adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here. The rotor structure 100 is rotatably arranged in the stator.

[0072] The above is only an embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields based on the technical concept of the present application, and the contents of the present application specification and drawings are included in the patent protection scope of the present application.

Claims

1. A rotor structure, wherein, The rotor structure comprises: a rotor core; a plurality of first magnetic pole assemblies, the plurality of first magnetic pole assemblies are arranged at intervals along a circumferential direction of the rotor core, each of the first magnetic pole assemblies comprises a first magnetic steel slot and a second magnetic steel slot, the first magnetic steel slot comprises a symmetric segment and an asymmetric segment connected to each other, the symmetric segment is symmetrically arranged with the second magnetic steel slot, and the asymmetric segment extends along the circumferential direction of the rotor core.

2. The rotor structure of claim 1, wherein, The two side walls of the asymmetric segment in the radial direction of the rotor core are arranged in an arc shape.

3. The rotor structure of claim 1 or 2, wherein, The interval between the two side walls of the asymmetric segment in the radial direction of the rotor core is h1, and 2mm≤h1≤3.5mm.

4. The rotor structure of claim 1, wherein, The side wall of the asymmetric segment away from the symmetric segment is connected to at least one of the two side walls in the radial direction of the rotor core through a round corner.

5. The rotor structure of claim 1, wherein, The rotor structure further comprises a plurality of second magnetic pole assemblies arranged at intervals along the circumferential direction of the rotor core, the plurality of second magnetic pole assemblies are arranged correspondingly with the plurality of first magnetic pole assemblies, and each of the second magnetic pole assemblies is located on one side of the corresponding first magnetic pole assembly in the radial direction of the rotor core.

6. The rotor structure of claim 5, wherein, The second magnetic pole assembly is located on the side of the corresponding first magnetic pole assembly close to the rotor shaft center of the rotor core.

7. The rotor structure of claim 5, wherein, The second magnetic steel slot is arranged at an angle with the symmetric segment. Each of the second magnetic pole assemblies comprises two symmetrically arranged third magnetic steel slots, and the two third magnetic steel slots are arranged at an angle.

8. The rotor structure of claim 7, wherein, The side wall of the asymmetric segment away from the symmetric segment is arranged in parallel with the side wall of the adjacent third magnetic steel slot in the radial direction of the rotor core.

9. The rotor structure of claim 8, wherein, The interval between the side wall of the asymmetric segment away from the symmetric segment and the adjacent third magnetic steel slot is h2, and 2mm≤h2≤4mm.

10. An electric machine wherein, The motor comprises: a stator; a rotor structure as claimed in any one of claims 1 to 9, the rotor structure being arranged rotatably in the stator.

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