Rotor punching sheet, motor rotor and permanent magnet synchronous motor

Abstract

The invention relates to the technical field of motors, and particularly discloses a rotor punching sheet, a motor rotor and a permanent magnet synchronous motor, the rotor punching sheet comprises a punching sheet body, and the punching sheet body is provided with a plurality of magnetic pole areas; at least three layers of magnetic steel groove groups are arranged in each magnetic pole area at intervals along the radial direction, and the configuration of the at least three layers of magnetic steel groove groups at least comprises that two layers of magnetic steel groove groups adopt differential topological configurations; wherein the punching sheet body is provided with a plurality of pairs of auxiliary grooves at the outer edge contour of each magnetic pole area, and each pair of auxiliary grooves are symmetrically distributed relative to the magnetic pole shaft; a first arc-shaped section and a second arc-shaped section are arranged on the outer edge contour of each magnetic pole area of the punching sheet body, the first arc-shaped section and the second arc-shaped section are connected at a magnetic pole shaft and are symmetrically arranged relative to the magnetic pole shaft, and the distances from any two points on the first arc-shaped section or the second arc-shaped section to the circle center are not equal. The rotor punching sheet can synchronously realize economic control of the use amount of the permanent magnets, remarkable reduction of motor torque pulsation and effective suppression of electromagnetic noise.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a rotor lamination, a motor rotor, and a permanent magnet synchronous motor. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) have become a core component of new energy vehicle drive systems due to their significant advantages in high efficiency, high power density, and high torque density. Their performance directly determines the range, driving experience, and ride comfort of new energy vehicles. In the electromagnetic design of PMSMs, the topology of the rotor laminations is a key element. The layout of the magnet slots on the rotor laminations (i.e., the topology type) directly determines the sinusoidality of the air gap magnetic field, which in turn affects the torque ripple amplitude, electromagnetic force, and electromagnetic noise level. These performance indicators are precisely the core requirements of new energy vehicles for drive motors, especially low torque ripple and low electromagnetic noise, which are crucial for improving the vehicle's NVH (noise, vibration, and harshness) performance.

[0003] Currently, the rotor laminations of permanent magnet synchronous motors generally adopt a double-layer radial topology, typically such as double-V topology, +V topology, +U topology, and V+U topology. Although this type of topology takes into account the balance between the motor's external characteristics (speed-torque operating curve), the amount of permanent magnets used, and the basic electromagnetic performance during the design process, it has inherent technical defects: in order to control the amount of permanent magnets used, it is difficult to achieve an ideal sinusoidal air gap magnetic field in the layout of the magnet slots, resulting in a high content of low-order spatial harmonics (such as the 3rd, 5th, and 7th harmonics) in the permanent magnet magnetomotive force. These low-order harmonics interact with the armature reaction magnetomotive force harmonics and the cogging magnetic permeability harmonics, which easily generate electromagnetic force waves with large amplitude and low order. These low-order force waves not only aggravate torque pulsation but also easily couple with the inherent modes of the motor stator, housing, and other structures, causing strong vibrations and radiating electromagnetic noise.

[0004] In addition, in the existing technology, although the single-layer magnet rotor has a simple structure, the air gap magnetic field is a square wave or a flat-top wave, and the low-order harmonic problem is more prominent. Some multi-layer magnet rotors have not made full use of the advantages of radial layering magnetic field shaping, and still cannot effectively solve the problem of synergistic optimization of torque pulsation and electromagnetic noise while controlling the amount of permanent magnets used, making it difficult to meet the NVH performance requirements of new energy vehicles for drive motors. Summary of the Invention

[0005] This application aims to propose a rotor lamination, a motor rotor, and a permanent magnet synchronous motor to at least solve the problems in existing permanent magnet motor technology, such as the high content of low-order spatial harmonics in the permanent magnet magnetomotive force, the interaction between low-order harmonics and armature reaction magnetomotive force harmonics and cogging magnetic permeability harmonics exacerbating torque pulsation, and the easy coupling with the inherent modes of the motor stator, housing, and other structures, leading to significant vibration and noise.

[0006] In a first aspect, this application provides a rotor lamination, comprising: A lamination body having multiple magnetic pole regions; In each magnetic pole region, at least three layers of magnetic slots are arranged radially at intervals, and the configuration of the at least three layers of magnetic slots includes at least two layers of magnetic slots employing differentiated topological configurations; wherein... The lamination body has several pairs of auxiliary grooves formed on the outer edge contour of each magnetic pole region, and each pair of auxiliary grooves is symmetrically distributed about the magnetic pole axis; and / or The lamination body has a first arc segment and a second arc segment on the outer edge contour of each magnetic pole region. The first arc segment and the second arc segment are connected at the magnetic pole axis and are symmetrically arranged about the magnetic pole axis. The distances from any two points on the first arc segment or the second arc segment to the center of the circle are not equal.

[0007] In some embodiments, the first arc segment has a first endpoint and a second endpoint disposed opposite to each other along its extension direction; the second arc segment shares an endpoint with the second endpoint at one end along its extension direction, and has a third endpoint at the other end, wherein the first endpoint and the third endpoint are symmetrically distributed about the magnetic pole axis.

[0008] In some embodiments, within each magnetic pole region, a Cartesian coordinate system is established with the center of the lamination body, wherein the ordinate axis of the Cartesian coordinate system is collinear with the magnetic pole axis. The coordinates of the first endpoint satisfy the expression: , ; The coordinates of the second endpoint satisfy the expression: , ; The coordinates of the third endpoint satisfy the expression: , ; In the formula, The outer diameter of the rotor. The length of the air gap. denoted by , where represents the angle of each magnetic pole, and k represents the air gap coefficient.

[0009] In some embodiments, each magnetic pole angle satisfies the expression: In the formula, This represents the number of magnetic poles.

[0010] In some embodiments, each layer of the magnetic steel groove group takes the magnetic pole axis as a common reference axis, and for each layer of the magnetic steel groove group in the magnetic pole region, the magnetic steel structural parameters on both sides of the magnetic pole axis are set in a completely symmetrical manner.

[0011] In some embodiments, the at least three layers of magnet slots include a first magnet slot group, a second magnet slot group, and a third magnet slot group arranged radially at intervals starting from the center of the lamination body. The first magnet slot group has a U-shaped topology and includes a first magnet slot, a second magnet slot, and a third magnet slot. The first magnet slot and the third magnet slot are symmetrically arranged about the magnetic pole axis. The second magnet slot is located on the magnetic pole axis and has a first portion and a second portion located on both sides of the magnetic pole axis. The first portion and the second portion are symmetrically arranged about the magnetic pole axis.

[0012] In some embodiments, the second magnet slot group and the third magnet slot group have a V-shaped topological configuration. The second magnet slot group includes a fourth magnet slot and a fifth magnet slot, and the third magnet slot group includes a sixth magnet slot and a seventh magnet slot. The fourth magnet slot and the fifth magnet slot are symmetrically arranged about the magnetic pole axis, and the sixth magnet slot and the seventh magnet slot are symmetrically arranged about the magnetic pole axis.

[0013] In some embodiments, the magnetic pole regions are used to form rotor magnetic poles and the number of such regions is even, with each magnetic pole region being evenly spaced circumferentially along the central axis of the lamination body.

[0014] In a second aspect, this application provides an electric motor rotor, the electric motor rotor comprising rotor laminations as described in any of the first aspects above, wherein a plurality of rotor laminations are stacked to form the rotor core of the electric motor rotor.

[0015] Thirdly, this application provides a permanent magnet synchronous motor, which includes a motor rotor as described in the second aspect above.

[0016] Compared with the prior art, the technical solutions provided by the above embodiments of this application have at least the following beneficial effects or advantages: The rotor lamination disclosed in this application is based on the division of magnetic pole regions in the lamination body to ensure independent control of the magnetic field of a single magnetic pole and avoid crosstalk between magnetic poles. At least three layers of magnetic steel slots are arranged radially at intervals within each magnetic pole region, forming a complementary magnetic potential space based on the radial layout of at least two layers of differentiated topologies. The magnetic field peaks of different layers of magnets are matched with the transition regions, thus weakening the 3rd and 5th harmonics through harmonic phase misalignment. The second-lowest spatial harmonics are optimized to improve the sinusoidal nature of the air gap magnetic field. The layered layout does not expand the volume of the magnet slots, thus controlling the amount of permanent magnets used. The first and second arc-shaped segments on the outer edge of the magnetic pole region are connected at the magnetic pole axis and are symmetrically distributed. The difference in distance from any two points to the center of the circle makes the air gap gradually change along the arc segment. A smaller air gap is maintained near the magnetic pole axis to ensure the peak magnetic flux density required for torque. The air gap gradually increases at the edge of the magnetic pole to allow the magnetic flux density to decay slowly. This not only eliminates the additional harmonics caused by sudden changes in magnetic flux density, but also changes the frequency characteristics of low-order force waves, allowing them to avoid the inherent mode range of the motor structure and preventing the resonance amplification of vibration and noise. At the same time, the symmetrical auxiliary grooves on the outer edge of the magnetic pole smooth the air gap magnetic reluctance fluctuations through circumferential micro-perturbation, weakening the core source of torque pulsation, the tooth cogging torque. The three dimensions of magnetic field source, magnetic reluctance distribution, and vibration frequency work synergistically to achieve economical control of permanent magnet usage, significant reduction of torque pulsation, and effective suppression of electromagnetic noise while maintaining the external characteristics of the motor.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the rotor lamination structure according to an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the magnetic pole region according to an embodiment of this application; Figure 3 This is a schematic diagram of the structure of the magnetic pole region according to an embodiment of this application; Figure 4 This is another structural schematic diagram of a rotor lamination according to an embodiment of this application; Figure 5 This is yet another structural schematic diagram of the magnetic pole region according to an embodiment of this application; Figure 6 This is another structural schematic diagram of the rotor lamination according to an embodiment of this application; Figure 7 This is another structural schematic diagram of the magnetic pole region according to an embodiment of this application.

[0020] Figure label: 100. Rotor laminations; 10. Stamped body; 11. Through hole; 20. Magnetic pole region; 21. First magnet slot group; 211. First magnet slot; 212. Second magnet slot; 213. Third magnet slot; 22. Second magnet slot group; 221. Fourth magnet slot; 222. Fifth magnet slot; 23. Third magnet slot group; 231. Sixth magnet slot; 232. Seventh magnet slot; 24. Auxiliary groove; 25. First arc-shaped segment; 26. Second arc-shaped segment; a. First endpoint; b. Second endpoint; c. Third endpoint; d. Magnetic pole axis. Detailed Implementation

[0021] The embodiments of this application are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. It should be understood that the specific embodiments described herein are merely for explaining this application and are not intended to limit this application.

[0022] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] Please see Figure 1As shown in Figure 7, this embodiment provides a rotor lamination 100, which includes a lamination body 10. The lamination body 10 has multiple magnetic pole regions 20. Specifically, the outer contour of the rotor lamination 100 can be circular or near-circular. This contour can ensure the dynamic balance performance of the rotor when rotating at high speed and avoid centrifugal force fluctuations caused by irregular contours. For example, an eccentric contour is prone to radial vibration, while a circular contour can make the centrifugal force of the rotor uniform in all directions and reduce the impact on the bearings. A through hole 11 is provided at the center O of the rotor lamination 100. The through hole 11 is used to pass through the motor shaft. Multiple magnetic pole regions 20 are arranged along the circumference of the rotor lamination 100. The multiple magnetic pole regions 20 are sequentially adjacent. In this embodiment, there can be six or eight magnetic pole regions 20. Of course, other numbers of magnetic pole regions 20 can also be set. The number of magnetic pole regions 20 can be flexibly adjusted according to the motor torque requirements to adapt to different speed and torque scenarios. The specific selection is based on actual needs. The adjacent design of multiple magnetic pole regions 20 can make the rotor magnetic field continuously distributed along the circumference and avoid sudden changes in magnetic flux between adjacent magnetic poles.

[0025] Furthermore, in combination Figure 1 and Figure 3 In each magnetic pole region 20, at least three layers of magnet slots are arranged radially at intervals. These slots are used to install and fix the magnets. The configuration of the at least three layers of magnet slots includes at least two layers with differentiated topological configurations. In this embodiment, the topological configuration can include V-shapes and U-shapes. The three layers of magnet slots are arranged in a differentiated topology of "outer V-shape + middle V-shape + inner U-shape". The outer layer of magnet slots is V-shaped, with its opening facing the outer contour of the rotor lamination 100. This topology allows the magnet slots to be distributed closer to the air gap, enabling direct... The main waveform affecting the air gap magnetic field is that the V-shaped magnet can generate a magnetic flux density peak that meets the rated torque requirements of the motor. The middle layer magnet slot group is set in a V shape, and its opening angle is smaller than that of the outer V-shape. When the outer magnetic field decays from the peak to the edge, a plateau region is likely to appear. The middle layer V-shaped magnet can fill this region, making the magnetic field transition smoother. The inner layer magnet slot group is set in a U shape, and its opening faces the outer contour of the rotor lamination 100. This differentiated topology can compensate for the transition region of the upper magnetic field and can specifically weaken low-order spatial harmonics, such as the 3rd and 5th harmonics.

[0026] Meanwhile, the low-order harmonics generated by the outer double V-shaped magnets are out of phase with the low-order harmonics of the same order generated by the inner U-shaped magnets. After they are superimposed in the air gap, the amplitude of the low-order harmonics is significantly reduced. The weakening of the low-order harmonics can directly reduce the coupling effect between the harmonics and the armature reaction and the cogging magnetic permeability. Since the low-order harmonics are prone to generate electromagnetic force waves with low order and large amplitude, weakening them can reduce the intensity of the electromagnetic force waves, thereby reducing torque pulsation. At the same time, the radially spaced layered design does not require expanding the overall volume of the magnet slot. Each layer of magnet slot only covers the corresponding radial area. Compared with a single-layer large-volume magnet slot, the amount of permanent magnets used can be reduced.

[0027] For example, in combination Figure 4 and Figure 5 The lamination body 10 has several pairs of auxiliary grooves 24 on the outer edge contour of each magnetic pole region 20. Each pair of auxiliary grooves 24 is symmetrically distributed about the magnetic pole axis d, and each pair of grooves is mirrored with the magnetic pole axis d as the line of symmetry. This avoids the magnetic reluctance imbalance on both sides of the magnetic pole caused by a single auxiliary groove 24. Due to the periodic distribution of the stator tooth slots, the air gap magnetic reluctance will exhibit a stepped fluctuation with low tooth section and high slot section. The auxiliary grooves 24 form a local high magnetic reluctance region on the outer edge of the rotor. When the stator teeth pass through the rotor, they first contact the grooves and then enter the normal outer contour region. The change in magnetic reluctance changes from a steep step to a gentle slope, which reduces the amplitude of the tooth slot magnetic permeability harmonic. Since the tooth slot torque is positively correlated with the amplitude of the magnetic permeability harmonic, the tooth slot torque is reduced after the magnetic permeability harmonic is weakened, thereby reducing the high-frequency component of torque pulsation. At the same time, the symmetrical distribution ensures that the magnetic pull on the left and right sides of the magnetic pole is always equal when the rotor rotates, avoiding the introduction of additional radial vibration, which would cause high-frequency noise.

[0028] For example, in combination Figure 6 and Figure 7 The lamination body 10 has a first arc segment 25 and a second arc segment 26 on the outer edge contour of each magnetic pole region 20. The first arc segment 25 and the second arc segment 26 are connected at the magnetic pole axis d and are symmetrically arranged about the magnetic pole axis d. The distances from any two points on the first arc segment 25 or the second arc segment 26 to the center of the circle are not equal. The radius of curvature of the two arc segments changes with the circumferential angle, forming a non-uniform air gap. Under a uniform air gap, the magnetic flux density at the edge of the magnetic pole will drop sharply due to magnetic circuit saturation, which is prone to generating high-order harmonics. The non-uniform air gap design expands the transition range of magnetic flux density from the peak to the edge, reducing the amplitude of high-order harmonics. At the same time, the non-uniform air gap changes the frequency of electromagnetic force waves, avoids the natural frequency of the motor housing, prevents vibration amplification caused by resonance, and ultimately reduces electromagnetic noise.

[0029] It should be noted that the lamination body 10 in this embodiment significantly weakens the low-order spatial harmonics in the permanent magnet magnet potential and reduces electromagnetic noise by setting at least three layers of magnetic steel grooves, auxiliary grooves 24 and a non-circular arc section of the outer edge contour. In practical application scenarios, at least three layers of magnetic steel grooves can be combined with auxiliary grooves 24, or at least three layers of magnetic steel grooves can be combined with a non-circular arc section of the outer edge contour. It should be understood that neither of the above two combination configurations deviates from the technical concept of this embodiment and falls within the protection scope of this embodiment.

[0030] The rotor lamination 100 provided in this embodiment is based on the division of the magnetic pole region 20 of the lamination body 10 to achieve independent control of the magnetic field of a single magnetic pole to avoid crosstalk between magnetic poles. At least three layers of magnetic steel slots are arranged radially at intervals within each magnetic pole region 20, forming a complementary magnetic potential space based on the radial layout of at least two layers of differentiated topologies. The magnetic field peaks of different layers of magnets are matched with the transition region, thus weakening the 3rd and 5th harmonics through harmonic phase misalignment. The second-lowest spatial harmonics are optimized to improve the sinusoidal nature of the air gap magnetic field. The layered layout does not expand the volume of the magnet slots, thus controlling the amount of permanent magnets used. The first arc segment 25 and the second arc segment 26 on the outer edge of the magnetic pole region 20 are connected at the magnetic pole axis d and are symmetrically distributed. The difference in distance from any two points to the center of the circle makes the air gap gradually change along the arc segment. A small air gap is maintained near the magnetic pole axis d to ensure the peak magnetic flux density required for torque. The air gap gradually increases at the edge of the magnetic pole to allow the magnetic flux density to decay slowly. This not only eliminates the additional harmonics caused by the sudden change in magnetic flux density, but also changes the frequency characteristics of the low-order force wave, making it avoid the inherent mode range of the motor structure and preventing the resonance amplification of vibration and noise. At the same time, the symmetrical auxiliary groove 24 on the outer edge of the magnetic pole smooths the air gap magnetic reluctance fluctuation through circumferential micro-perturbation, weakening the core source of torque pulsation, the tooth cogging torque. It works synergistically from the three dimensions of magnetic field source, magnetic reluctance distribution, and vibration frequency. Under the premise of maintaining the external characteristics of the motor, it simultaneously achieves economical control of the amount of permanent magnets used, significant reduction of torque pulsation, and effective suppression of electromagnetic noise.

[0031] Please see Figure 2 and Figure 3 In some embodiments, each layer of magnet slots uses the magnetic pole axis d as a common reference axis. For each layer of magnet slots within the magnetic pole region 20, the magnetic structural parameters on both sides of the magnetic pole axis d are set symmetrically. Using the magnetic pole axis d as a unified reference ensures that the magnetic field centers of each radially layered magnet slot are perfectly aligned, avoiding the superposition disorder of magnetic potentials caused by reference offset, thus laying a spatial foundation for subsequent precise magnetic potential complementarity. Since unilateral magnetic pull easily causes rotor radial vibration, exacerbates bearing wear, and introduces additional torque pulsation, the complete symmetry of the magnetic structural parameters on both sides of each layer ensures absolute balance of magnetic flux on both sides of the magnetic pole axis d, completely eliminating unilateral magnetic pull and ensuring the stability of the motor during high-speed rotation. Simultaneously, it allows the low-order spatial harmonics (such as the 3rd, 5th, and 6th harmonics) generated by each layer of magnet slots to be controlled. The phase-controlled complementarity significantly weakens the harmonic amplitude, reduces the coupling effect between harmonics and armature reaction and cogging magnetic permeability, thereby reducing the intensity of electromagnetic force waves and torque pulsation, avoiding vehicle start-up jerking and high-speed vibration, and also avoiding the resonance risk of low-order force waves and motor structural modes, indirectly reducing electromagnetic noise; in addition, the completely symmetrical construction parameters also simplify the stamping process, reduce processing errors, improve the consistency of stamping during mass production, and ensure the stability of motor performance.

[0032] Please see Figure 2 and Figure 3 In some embodiments, at least three layers of magnet slots include a first magnet slot group 21, a second magnet slot group 22, and a third magnet slot group 23 arranged radially and spaced apart along the lamination body 10. The first magnet slot group 21 has a U-shaped topological configuration and includes a first magnet slot 211, a second magnet slot 212, and a third magnet slot 213. The first magnet slot 211 and the third magnet slot 213 are symmetrically arranged about the magnetic pole axis d. The second magnet slot 212 is located on the magnetic pole axis d and has a position on the magnetic pole axis d. The first and second parts on both sides of the magnetic pole axis d are symmetrically arranged about the magnetic pole axis d. Specifically, in this embodiment, the rotor lamination 100 adopts a double V+U topology. The magnetic steel slots near the center of the rotor lamination 100 are defined as the first layer, and the magnetic steel slot group near the outer edge of the rotor is defined as the third layer. The first layer of magnetic steel slots is U-shaped, and the second and third layers of magnetic steel slot groups are double V-shaped. Of course, the outer circle of the rotor magnetic pole can be deformed in three ways according to the specific performance requirements of different motors.

[0033] It should be understood that the dual-dimensional symmetrical design of the first magnet slot 211 and the third magnet slot 213 about the magnetic pole axis d, and the first and second parts of the second magnet slot 212, ensures that the magnetic field generated by the permanent magnet is evenly distributed along the magnetic pole axis d, eliminating the hidden danger of unilateral magnetic pull, avoiding radial vibration and bearing wear, and laying the magnetic field foundation for the smooth operation of the motor; the U-shaped topology structure allows the magnetomotive force to form a distribution with a central magnetic density and a gradual attenuation at the edges in the magnetic pole region 20, which not only ensures the peak value of the air gap magnetic density to meet the rated torque requirements through the central second magnet slot 212, but also through the two The side-mounted magnet slots broaden the magnetic field coverage, avoiding magnetic flux density spikes or steep drops and reducing non-sinusoidal components. Simultaneously, the magnetomotive force harmonics generated by the U-shaped topology can form phase complementarity with the harmonics of the radially spaced second magnet slot group 22 and the third magnet slot group 23, significantly weakening the third and fifth order spatial harmonics, thereby reducing the large amplitude electromagnetic force waves caused by harmonic coupling and reducing the risk of torque pulsation and resonance noise. In addition, the partitioned configuration of multiple magnet slots does not require increasing the volume of a single slot, and the overall usage can be controlled by precisely allocating the permanent magnet volume, thus meeting cost control requirements while ensuring magnetic field performance.

[0034] Continue reading Figure 2 and Figure 3In some embodiments, the second magnet slot group 22 and the third magnet slot group 23 are arranged in a V-shaped topology. The second magnet slot group 22 includes a fourth magnet slot 221 and a fifth magnet slot 222, and the third magnet slot group 23 includes a sixth magnet slot 231 and a seventh magnet slot 232. The fourth magnet slot 221 and the fifth magnet slot 222 are symmetrically arranged about the magnetic pole axis d, and the sixth magnet slot 231 and the seventh magnet slot 232 are symmetrically arranged about the magnetic pole axis d. The two V-shaped magnet slot groups can form a radially layered magnetic field complementarity with the inner U-shaped first magnet slot group 21. The magnetomotive force peak region of the V-shaped slot group and the magnetomotive force transition region of the U-shaped slot group are connected to each other, which can not only enhance the sinusoidal nature of the air gap magnetic field, but also further weaken the low-order spatial harmonics through the harmonic phase misalignment of different layers of magnetomotive force, reduce the electromagnetic force waves generated by harmonic coupling, and provide multi-layer protection for reducing torque pulsation and electromagnetic noise.

[0035] Continue reading Figure 2 and Figure 3 Optionally, the ends of the first magnet slot 211, the third magnet slot 213, the fourth magnet slot 221, the fifth magnet slot 222, the sixth magnet slot 231, and the seventh magnet slot 232 that are away from the magnetic pole axis d extend to the outer edge contour near the magnetic pole region 20. The angle formed by the fourth magnet slot 221 and the fifth magnet slot 222 is smaller than the angle formed by the sixth magnet slot 231 and the seventh magnet slot 232. The extension of the ends of multiple sets of magnet slots away from the magnetic pole axis d to the outer edge contour allows the magnets to be closer to the air gap region, allowing the magnetomotive force to act directly on the key control range of the air gap magnetic field, reducing the leakage flux loss inside the rotor, and strengthening the amplitude stability of the air gap magnetic flux density to ensure the rated torque output of the motor. The angle between the fourth and fifth magnet slots 222 is smaller than the angle between the sixth and seventh magnet slots 232. The inner narrow-opening V-shaped slot group can accurately control the magnetomotive force concentration in the magnetic pole center region and avoid magnetic flux density spikes. The outer wide-opening V-shaped slot group can also control the magnetomotive force concentration in the magnetic pole center region and avoid magnetic flux density spikes. The shaped groove group can broaden the magnetic field coverage at the edge of the magnetic pole and guide the magnetic flux density to decay gradually. The combination of the two makes the distribution of air gap magnetic flux density from the center to the edge closer to an ideal sine wave, which greatly reduces the high-order harmonics caused by non-sine components.

[0036] Please see Figure 3 , Figure 6 and Figure 7 In some embodiments, the first arc segment 25 has a first endpoint a and a second endpoint b that are arranged opposite to each other along its extension direction; one end of the second arc segment 26 shares an endpoint with the second endpoint b of the first arc segment 25, and the second arc segment 26 has a third endpoint c that is arranged opposite to the shared endpoint along its extension direction, and the first endpoint a and the third endpoint c are symmetrically distributed about the magnetic pole d axis along the circumferential direction of the rotor lamination 100.

[0037] Furthermore, within each magnetic pole region, a Cartesian coordinate system is established with the center of the lamination body, wherein the vertical axis of the Cartesian coordinate system is collinear with the magnetic pole axis, and the coordinates of the first endpoint satisfy the expression: , ; The coordinates of the second endpoint satisfy the expression: , ; The coordinates of the third endpoint satisfy the expression: , ; In the formula, This refers to the rotor's outer diameter, in mm. This refers to the air gap length, in mm. The angle of each magnetic pole is represented by k, which represents the air gap coefficient. When k > 1, a non-uniform air gap is generated.

[0038] Furthermore, each magnetic pole angle satisfies the expression: In the formula, This represents the number of magnetic poles.

[0039] In this embodiment, the first endpoint A and the third endpoint C are arranged symmetrically along the circumference about the d-axis of the magnetic pole. Combined with the coordinate formula based on parameters such as rotor outer diameter and air gap length, the non-uniform outer edge of the magnetic pole first arc segment 25 and the outline of the first arc segment 25 can be accurately constructed. This can guide the magnetic flux density of the magnetic pole region 20 to gradually decrease from the center peak to the edge, avoiding high-order harmonics caused by the sharp drop in magnetic flux density under a uniform air gap. At the same time, it changes the frequency characteristics of the electromagnetic force wave, avoiding the resonance range of the inherent mode of the motor structure. This weakens the torque pulsation caused by harmonic coupling and reduces the electromagnetic noise amplified by resonance.

[0040] Meanwhile, through parametric design that links Cartesian coordinates with multi-endpoint formulas, the position of the arc segment endpoints can be flexibly adjusted according to core parameters such as the number of motor poles, outer diameter, and air gap length. This ensures that the variation law of the non-uniform air gap is precisely matched with the magnetic field requirements of the poles, significantly improving the adaptability and flexibility of the lamination design. It can cover the performance scenarios of different types of new energy vehicle drive motors. The distribution of the arc segment endpoints, combined with parameters such as pole angle and rotor outer diameter, ensures that the outer edge contour of each pole region 20 is consistent with the angular characteristics of the pole itself, avoiding abrupt changes in the air gap between adjacent poles. This ensures the continuous distribution of the magnetic field in the circumferential direction of the rotor, effectively controlling the leakage magnetic loss between poles. This not only improves the magnetic energy utilization rate to ensure torque output but also further strengthens the sinusoidal nature of the magnetic field, helps to weaken low-order spatial harmonics, and synergistically optimizes the overall performance of the motor.

[0041] In some embodiments, an electric motor rotor is provided, the electric motor rotor including rotor laminations as described in any of the above embodiments, wherein a plurality of said rotor laminations are stacked to form the rotor core of said electric motor rotor.

[0042] In some embodiments, a permanent magnet synchronous motor is also provided, the permanent magnet synchronous motor including the motor rotor as described in the above embodiments.

[0043] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the invention.

[0044] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0045] Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The reference to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily indicate the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0046] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A rotor lamination, characterized in that, include: A lamination body having multiple magnetic pole regions; In each magnetic pole region, at least three layers of magnetic slots are arranged radially at intervals, and the configuration of the at least three layers of magnetic slots includes at least two layers of magnetic slots employing differentiated topological configurations; wherein... The lamination body has several pairs of auxiliary grooves on the outer edge contour of each magnetic pole region, and each pair of auxiliary grooves is symmetrically distributed about the magnetic pole axis; or... The lamination body has a first arc segment and a second arc segment on the outer edge contour of each magnetic pole region. The first arc segment and the second arc segment are connected at the magnetic pole axis and are symmetrically arranged about the magnetic pole axis. The distances from any two points on the first arc segment or the second arc segment to the center of the circle are not equal.

2. The rotor lamination according to claim 1, characterized in that, The first arc segment has a first endpoint and a second endpoint that are arranged opposite to each other along its extension direction; the second arc segment has a third endpoint at one end along its extension direction and the second endpoint at the other end, and the first endpoint and the third endpoint are symmetrically distributed about the magnetic pole axis.

3. The rotor lamination according to claim 2, characterized in that, Within each magnetic pole region, a Cartesian coordinate system is established with the center of the lamination body, wherein the vertical axis of the Cartesian coordinate system is collinear with the magnetic pole axis. The coordinates of the first endpoint satisfy the expression: , ; The coordinates of the second endpoint satisfy the expression: , ; The coordinates of the third endpoint satisfy the expression: , ; In the formula, The outer diameter of the rotor. The length of the air gap. denoted by , where represents the angle of each magnetic pole, and k represents the air gap coefficient.

4. The rotor lamination according to claim 3, characterized in that, Each magnetic pole angle satisfies the expression: In the formula, This represents the number of magnetic poles.

5. The rotor lamination according to any one of claims 1-4, characterized in that, Each layer of the magnetic steel groove group takes the magnetic pole axis as a common reference axis, and for each layer of the magnetic steel groove group in the magnetic pole region, the magnetic steel structural parameters on both sides of the magnetic pole axis are set in a completely symmetrical manner.

6. The rotor lamination according to claim 5, characterized in that, The at least three layers of magnet slots include: a first magnet slot group, a second magnet slot group, and a third magnet slot group arranged radially at intervals starting from the center of the lamination body. The first magnet slot group has a U-shaped topological configuration and includes a first magnet slot, a second magnet slot, and a third magnet slot. The first magnet slot and the third magnet slot are symmetrically arranged about the magnetic pole axis. The second magnet slot is located on the magnetic pole axis and has a first part and a second part located on both sides of the magnetic pole axis. The first part and the second part are symmetrically arranged about the magnetic pole axis.

7. The rotor lamination according to claim 5, characterized in that, The second magnet slot group and the third magnet slot group have a V-shaped topological configuration. The second magnet slot group includes a fourth magnet slot and a fifth magnet slot, and the third magnet slot group includes a sixth magnet slot and a seventh magnet slot. The fourth magnet slot and the fifth magnet slot are symmetrically arranged about the magnetic pole axis, and the sixth magnet slot and the seventh magnet slot are symmetrically arranged about the magnetic pole axis.

8. The rotor lamination according to claim 1, characterized in that, The magnetic pole regions are used to form rotor magnetic poles and the number of them is even. Each magnetic pole region is evenly distributed circumferentially along the central axis of the lamination body.

9. A motor rotor, characterized in that, The motor rotor includes rotor laminations as described in any one of claims 1-8, and a plurality of said rotor laminations are stacked to form the rotor core of the motor rotor.

10. A permanent magnet synchronous motor, characterized in that, The permanent magnet synchronous motor includes the motor rotor as described in claim 9.

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