Rotor laminations, rotor cores, rotors, motors, and vehicles

Abstract

This invention provides a rotor lamination, a rotor core, a rotor, a motor, and a vehicle. The rotor lamination includes a lamination body, a shaft hole, and multiple slot groups. The shaft hole is disposed on the lamination body, and the multiple slot groups are disposed on the lamination body. Each slot group includes at least one magnetic slot, and each magnetic slot includes two magnet slots. Each magnet slot includes a first slot end and a second slot end on an axial end face, with the first slot end positioned closer to the shaft hole than the second slot end. The outer periphery of the lamination body includes an outer peripheral section on the axial end face, which includes multiple connected arc-shaped segments corresponding to the multiple slot groups. Each arc-shaped segment includes a first arc segment concentric with the shaft hole and a second arc segment discentric with the shaft hole. By employing a combination of the first and second arc segments, this invention can effectively improve the sinusoidal nature of the air gap magnetic field, reduce harmonics, lower motor torque pulsation, and improve vibration and noise issues while ensuring the motor's output torque.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor equipment, in particular to a rotor lamination, a rotor core, a rotor, a motor and a vehicle. BACKGROUND

[0002] At present, the rotor of the built-in permanent magnet motor is composed of a rotor lamination. As a key component of the rotor, the design of the rotor lamination directly determines the performance of the motor. However, due to the unreasonable design of the rotor lamination, the motor air gap magnetic field has a large number of harmonic components and serious distortion, which leads to high motor torque ripple and large vibration and noise. Therefore, how to reasonably design the rotor to improve the performance of the motor has become a problem to be solved. SUMMARY

[0003] The present application is directed to at least one of the problems existing in the prior art or related art.

[0004] To this end, a first aspect of the present application provides a rotor lamination.

[0005] A second aspect of the present application provides a rotor core.

[0006] A third aspect of the present application provides a rotor.

[0007] A fourth aspect of the present application provides a motor.

[0008] A fifth aspect of the present application provides a vehicle.

[0009] Therefore, according to the first aspect of the present application, a rotor lamination is provided, which comprises a lamination body, a shaft hole and a plurality of slot groups. The shaft hole is arranged on the lamination body. The plurality of slot groups are arranged on the lamination body, each slot group comprising at least one magnetic slot, each magnetic slot comprising two magnet slots, each magnet slot comprising a first slot end and a second slot end on an axial end face, the first slot end being arranged closer to the shaft hole than the second slot end. The outer periphery of the lamination body comprises an outer periphery section on the axial end face, the outer periphery section comprising a plurality of connected arc sections corresponding to the plurality of slot groups, each arc section comprising a first circular arc section concentric with the shaft hole and a second circular arc section concentric with the shaft hole.

[0010] The rotor lamination provided by the application comprises a lamination body, a shaft hole and a plurality of slot groups. The shaft hole is arranged on the lamination body, and the lamination body is a magnetic steel body. The shaft hole is used for assembling the rotating shaft of the rotor. The plurality of slot groups are arranged on the lamination body around the shaft hole. It is worth noting that the structure of each mounting portion in the plurality of mounting portions can be the same or partially the same, which can be adjusted according to actual needs. Each slot group comprises at least one magnetic slot, each magnetic slot comprises two magnet slots, each magnet slot is used for assembling a permanent magnet of the rotor, each magnet slot comprises a first slot end and a second slot end on the axial end face, the first slot end is arranged closer to the shaft hole than the second slot end, and when the distance between the first slot ends of the two magnet slots is not equal to the distance between the second slot ends of the two magnet slots, the two magnet slots are arranged in a V shape on the lamination body. The openings of the two magnet slots arranged in a V shape are away from the shaft hole. Further, the outer periphery of the lamination body comprises an outer periphery section on the axial end face, and the outer periphery section is a closed line section. The outer periphery section comprises a plurality of connected arc sections, one arc section corresponds to one slot group, and it is worth noting that the number of arc sections and the number of slot groups are equal to the number of magnetic poles of the motor. By arranging each arc section to comprise at least a first circular arc section with the same center as the shaft hole and a second circular arc section with a different center from the shaft hole, the motor can form a periodically varying unequal air gap between the outer periphery circle of the rotor and the inner periphery circle of the stator in the circumferential direction, thereby forming an alternation between the left arc section, the first circular arc section and the right arc section on the outer periphery circle of the rotor lamination, which can make the motor run more smoothly, optimize the rotor magnetic field distribution, effectively weaken the direct-axis and quadrature-axis armature reaction, significantly improve the motor torque ripple, reduce the motor operation vibration noise, and improve the user's comfort. At the same time, the motor stator and rotor iron loss are also reduced to some extent, which is conducive to improving the motor efficiency. At the same time, the application combines the advantages of the rotor lamination whole circle design and the pure eccentric design through the combination of the first circular arc section and the second circular arc section, without changing the average air gap length of the motor and ensuring the peak torque of the motor, effectively improving the air gap magnetic field, increasing the sine degree of the air gap magnetic density and back electromotive force waveform, reducing the harmonic ratio, and further reducing the torque ripple and the vibration noise of the motor. The application provides at least one V-shaped magnetic slot at each magnetic pole of the motor, and each arc section comprises at least a concentric first circular arc section and a non-concentric second circular arc section, so that the overall structure of the rotor lamination is more reasonable, the motor output torque is ensured, the motor air gap magnetic density distribution is effectively improved, the motor harmonic content is reduced, the motor torque ripple and vibration noise are improved, and an excellent motor design is realized.

[0011] In a possible design, further, any one of the two magnet slots comprises a straight slot section connected between the first slot end and the second slot end and close to the other magnet slot of the two magnet slots, the straight slot section comprises a far end away from the axial hole, and a line between the far end of the two magnet slots and the center of the axial hole forms a polar arc angle α, and a central angle of the first circular arc section is β, wherein,

[0012] In this design, for the two magnet slots in one magnet slot, any one of the two magnet slots comprises two straight sections connected between the first slot end and the second slot end, and the straight section close to the other magnet slot is the straight slot section. That is, the two magnet slots comprise a first magnet slot and a second magnet slot, the first magnet slot comprises a straight slot section facing the second magnet slot, the second magnet slot comprises a straight slot section facing the first magnet slot, each straight slot section comprises a far end away from the axial hole, and an included angle between the far end of the first magnet slot and the second magnet slot and the center of the axial hole is a polar arc angle α.

[0013] Further, the center of the circle where the first circular arc section is located overlaps with the center of the axial hole, and the central angle β of the first circular arc section refers to an included angle between the two end points of the first circular arc section and the center of the axial hole. Specifically, a line between one end point of the first circular arc section and the center of the axial hole is referred to as a first line, a line between the other end point of the first circular arc section and the center of the axial hole is referred to as a second line, and an included angle between the first line and the second line is the central angle β.

[0014] Further, since the ratio of the polar arc angle α and the central angle β has a great influence on the peak torque, torque ripple and air gap magnetic field of the motor, the smaller the β / α, the smaller the air gap magnetic field waveform distortion rate and the lower the motor torque ripple, but the lower the motor torque and power, and the larger the β / α, the more serious the air gap magnetic field waveform distortion and the larger the motor torque ripple. Therefore, the reasonable value of β / α plays a crucial role in the performance of the motor, and by limiting the ratio of β / α within the above range, the multi-objective optimization of motor torque, torque ripple and air gap harmonics can be achieved. Without changing the motor torque, the motor harmonic content can be effectively reduced, and the motor torque ripple can be improved.

[0015] In a possible design, further, the number of the second circular arc sections is two, and the two second circular arc sections are connected on both sides of the first circular arc section.

[0016] In the design, two second circular arc segments are connected on both sides of the first circular arc segment. Specifically, the two second circular arc segments include a left arc segment and a right arc segment, that is, for one magnetic pole of the motor, the arc-shaped segment includes a left arc segment, a first circular arc segment and a right arc segment connected in sequence. For adjacent magnetic poles, the left arc segment of one magnetic pole is connected with the right arc segment on the adjacent magnetic pole, and the right arc segment of one magnetic pole is connected with the left arc segment of the adjacent magnetic pole. Further, the center of the second circular arc segment does not overlap with the center of the shaft hole, that is, the outer periphery of the punching body is formed by the combination of the first circular arc segment arranged concentrically with the center of the shaft hole and the second circular arc segment arranged eccentrically. For the motor, the unequal air gap between the outer periphery circle of the rotor and the inner periphery circle of the stator can be periodically changed in the circumferential direction, so that the alternation between the left arc segment, the first circular arc segment and the right arc segment on the outer periphery circle of the rotor punching sheet is formed, which can make the motor run more smoothly, optimize the rotor magnetic field distribution, effectively weaken the cross-axis armature reaction, significantly improve the motor torque ripple, reduce the motor operation vibration noise, and improve the user's comfort. At the same time, the stator and rotor iron loss of the motor is also reduced to some extent, which is conducive to improving the motor efficiency. At the same time, the combination of the first circular arc segment and the second circular arc segment takes into account the advantages of the rotor punching sheet whole circle design and the pure eccentric design, without changing the average air gap length of the motor and ensuring the peak torque of the motor, effectively improving the air gap magnetic field, improving the sine degree of air gap magnetic density and back electromotive force waveform, reducing the harmonic ratio, and further reducing the torque ripple and the vibration noise of the motor.

[0017] In a possible design, further, the second circular arc segment includes at least one eccentric circular arc segment.

[0018] In the design, each second circular arc segment includes at least one eccentric circular arc segment. When the second circular arc segment includes one eccentric circular arc segment, for one magnetic pole of the motor, the arc-shaped segment includes one first circular arc segment and two eccentric circular arc segments. When the second circular arc segment includes two eccentric circular arc segments, for one magnetic pole of the motor, the arc-shaped segment includes one first circular arc segment and four eccentric circular arc segments. That is, the number of circular arc segments contained in the arc-shaped segment can be three, five, seven, etc. When the number of eccentric circular arc segments is multiple, for one arc-shaped segment, the unequal air gap between the outer periphery circle of the rotor of the rotor punching sheet and the inner periphery circle of the stator can be formed, which is beneficial to the smooth operation of the motor, optimizes the magnetic field distribution of the rotor with the rotor punching sheet, effectively weakens the cross-axis armature reaction, significantly improves the motor torque ripple, reduces the motor operation vibration noise, and improves the user's comfort.

[0019] In one possible design, at least two magnetic slots are provided, with the first slot ends of the two magnetic slots of each magnetic slot close to each other and the second slot ends of the two magnetic slots of each magnetic slot far from each other; the two magnetic slots include a first magnetic slot and a second magnetic slot, with the first magnetic slot being positioned closer to the shaft hole than the second magnetic slot, and the second magnetic slot forming a pole arc angle α, wherein the first magnetic slot and the second magnetic slot are symmetrical with respect to the center line of their respective magnetic poles.

[0020] In this design, corresponding to one magnetic pole of the motor, the slot group includes two magnetic slots. The first ends of the two magnetic slots in each slot are close to each other, while the second ends are far apart. That is, both magnetic slots are V-shaped, and the openings of the V-shaped slots formed by the two magnetic slots in each slot face the outer periphery of the lamination body, i.e., away from the shaft hole. Further, the two magnetic slots include a first magnetic slot and a second magnetic slot. The first magnetic slot is positioned closer to the shaft hole than the second magnetic slot; that is, the first end of the magnetic slot in the second magnetic slot is closer to the shaft hole than the first end of the magnetic slot in the second magnetic slot. It is worth noting that when there are two magnetic slots, the pole arc angle α mentioned in the aforementioned design refers to the angle formed by the two magnetic slots of the second magnetic slot. In other words, the second magnetic slot comprises two magnetic slots: a first magnetic slot and a second magnetic slot. The first magnetic slot includes a straight slot section facing the second magnetic slot, and the second magnetic slot includes a straight slot section facing the first magnetic slot. Each straight slot section includes a distal end away from the shaft hole. The angle formed by the lines connecting the distal ends of the first and second magnetic slots to the center of the shaft hole is the pole arc angle α. Furthermore, both the first and second magnetic slots are symmetrical with respect to the center line of their respective magnetic poles, thereby simplifying the structure of the motor with this rotor lamination, making it easier to manufacture and reducing production costs.

[0021] In one possible design, the angle formed by the extension lines of the straight groove segments of the two magnet slots in the first magnetic slot is the first opening angle, and the angle formed by the extension lines of the straight groove segments of the two magnet slots in the second magnetic slot is the second opening angle. The first opening angle is not equal to the second opening angle.

[0022] In this design, the angle formed by the extension lines of the straight slot segments of the two magnet slots in the first magnetic slot is the first opening angle, and the angle formed by the extension lines of the straight slot segments of the two magnet slots in the second magnetic slot is the second opening angle. The first opening angle is not equal to the second opening angle, which is beneficial to increasing the magnetic field strength under each magnetic pole, enabling magnetization. While increasing the motor output torque, it can further increase the ratio of the quadrature-axis inductance to the direct-axis inductance of the motor, thereby increasing the reluctance torque component and improving the motor's field weakening speed extension capability. Specifically, the first opening angle is greater than the second opening angle, or the first opening angle is less than the second opening angle.

[0023] In one possible design, the first opening angle is further smaller than the second opening angle.

[0024] In this design, the first opening angle of the first magnetic slot near the shaft hole is smaller than the second opening angle of the second magnetic slot far from the shaft hole, which can increase the magnetic field strength under each magnetic pole and achieve magnetization. While increasing the output torque of the motor, it can further increase the ratio of the quadrature axis inductance to the direct axis inductance of the motor, thereby increasing the reluctance torque component and improving the motor's field weakening speed extension capability.

[0025] In one possible design, the first arc segment is further symmetrical with respect to the centerline of the magnetic pole. The two second arc segments are also symmetrical with respect to the centerline of the magnetic pole.

[0026] In this design, the first arc segment is symmetrical with respect to the centerline of its respective magnetic pole. Two second arc segments are also symmetrical with respect to the centerlines of their respective magnetic poles. In other words, each arc segment is symmetrical with respect to the centerline of its respective magnetic pole. This allows the outer periphery formed by the multiple arc segments of the entire lamination body to have a periodically unequal air gap with the inner circumference of the stator. Without changing the average air gap length of the motor and ensuring a constant peak torque, this effectively improves the air gap magnetic field, increases the air gap magnetic flux density and the sinusoidal nature of the back EMF waveform, reduces the proportion of harmonics, and thus reduces torque pulsation, significantly lowering motor vibration and noise. Furthermore, designing the arc segments as symmetrical with respect to the centerlines of the magnetic poles reduces the processing difficulty of the rotor laminations and improves the product yield.

[0027] In one possible design, the first circular arc segments of the multiple arc segments all have the same arc length. The radii of the circles containing the first circular arc segments of the multiple arc segments are also all equal.

[0028] In this design, the first arc segment of multiple arc-shaped segments has an equal arc length, which further ensures a periodically unequal air gap between the outer circumference of the rotor and the inner circumference of the stator. This effectively improves the air gap magnetic field without changing the average air gap length of the motor and maintaining the peak torque. Furthermore, the radii of the circles containing the first arc segments of the multiple arc-shaped segments are all equal, meaning the multiple first arc segments are multiple arc segments on the same circle. This allows the projection of the maximum outer contour of the rotor lamination onto the axial end face to have a regular shape, making the space required for the rotor with these laminations relatively regular during high-speed rotation, i.e., cylindrical, thus facilitating the processing and fabrication of a matching stator.

[0029] In one possible design, the center of the second arc segment is located on the lamination body.

[0030] In this design, the center of the second arc segment is located on the lamination body, meaning the second arc protrudes in the direction away from the shaft hole. In other words, the centers of both the first and second arc segments are located on the lamination body. Therefore, the bending trends of the first and second arc segments are similar, which can better control the formation of a periodically varying air gap between the outer circumference of the rotor and the inner circumference of the stator. This results in smoother motor operation, optimized rotor magnetic field distribution, and effective reduction of quadrature and direct axis armature reaction. While ensuring the peak torque of the motor remains unchanged, it significantly improves motor torque pulsation, reduces motor vibration and noise, and enhances user comfort.

[0031] In one possible design, the slot assembly further includes an auxiliary slot disposed on the outer periphery of the lamination body.

[0032] In this design, each slot group has an auxiliary slot located on the outer periphery of the lamination body. This auxiliary slot effectively reduces the harmonic content in the motor's air gap magnetic field, thereby improving the sinusoidality of the air gap magnetic flux density waveform, reducing torque ripple, decreasing radial force caused by harmonics, lowering operating noise, and improving vibration noise, ultimately enhancing user comfort. Furthermore, by providing recessed auxiliary slots on the rotor laminations, this invention can also partially adjust the motor's no-load back EMF waveform and radial force, reducing the maximum no-load line back EMF. It is worth noting that the motor's torque ripple largely depends on the non-sinusoidal nature of the air gap magnetic field; the higher the harmonic content in the air gap magnetic field, the worse the motor's output torque waveform, the greater the ripple, and the greater the vibration noise.

[0033] In one possible design, the number of auxiliary slots is further increased to multiple, with the multiple auxiliary slots arranged at intervals and symmetrically arranged along the center line of the magnetic pole.

[0034] In this design, each slot group includes multiple auxiliary slots. For example, a slot group can have four auxiliary slots, which are arranged at intervals on the lamination body. The multiple auxiliary slots of a slot group are symmetrically arranged along the center line of the magnetic pole, and the number of auxiliary slots is at least two, arranged in pairs.

[0035] In one possible design, the auxiliary slot further includes two first auxiliary slots, which are symmetrically arranged on a first arc segment along the center line of the magnetic pole. And / or, the auxiliary slot further includes two second auxiliary slots, which are symmetrically arranged on two second arc segments along the center line of the magnetic pole.

[0036] In this design, the auxiliary slots include two first auxiliary slots and two second auxiliary slots. The two first auxiliary slots are symmetrically arranged on the first arc segment along the center line of the magnetic pole, and the two second auxiliary slots are arranged on the second arc segment along the center line of the magnetic pole. The two second auxiliary slots are respectively arranged on two different arc segments.

[0037] Furthermore, the depth of the first auxiliary slot is greater than that of the second auxiliary slot. That is, for the concentric first arc segment, the depth of the first auxiliary slot is larger, while for the eccentric second arc segment, the depth of the second auxiliary slot is smaller. By combining the first and second auxiliary slots with different depths, the harmonic content in the air gap magnetic field can be further reduced, thereby improving the sinusoidal nature of the air gap magnetic flux density waveform. This can effectively improve torque pulsation and radial force. At the same time, setting the auxiliary slots can also partially adjust the no-load back EMF waveform and reduce the maximum no-load line back EMF amplitude of the motor.

[0038] In one possible design, the depth of the first auxiliary groove is greater than or equal to 0.5 mm and less than or equal to 0.9 mm. And / or, the depth of the second auxiliary groove is greater than or equal to 0.1 mm and less than or equal to 0.7 mm.

[0039] In this design, when the depths of the first auxiliary slot and the second auxiliary slot meet the above-mentioned limits, it can be ensured that the auxiliary slots can effectively improve the motor performance while keeping their volume small, thus avoiding significant changes to the shape of the outer edge of the lamination body.

[0040] According to a second aspect of the present invention, a rotor core is provided, comprising rotor laminations provided by any of the above designs, wherein the number of rotor laminations is multiple, the multiple rotor laminations are stacked, and multiple slots of the multiple rotor laminations are axially connected to form multiple slots.

[0041] The rotor core provided by the present invention includes the rotor laminations provided by any of the above designs, and therefore has all the beneficial effects of the rotor laminations, which will not be repeated here.

[0042] According to a third aspect of the invention, a rotor is provided, comprising a rotor core provided by any of the above designs, and the rotor further comprising a plurality of permanent magnets respectively inserted into a plurality of slots.

[0043] The rotor provided by the present invention includes the rotor core provided by any of the above designs, and therefore has all the beneficial effects of the rotor core, which will not be repeated here.

[0044] According to a fourth aspect of the invention, an electric motor is provided, comprising a rotor provided by any of the above designs, and the electric motor further comprising a stator including an axially extending assembly cavity, the rotor being located within the assembly cavity.

[0045] The motor provided by the present invention includes the rotor provided by any of the above designs, and therefore has all the beneficial effects of the rotor, which will not be repeated here.

[0046] In one possible design, the minimum distance between the outer peripheral wall of the rotor and the inner peripheral wall of the stator is H1, and the maximum distance between the outer peripheral wall of the rotor and the inner peripheral wall of the stator is H2, wherein 0.15mm≤H2-H1≤0.35mm.

[0047] In this design, the minimum distance between the outer peripheral wall of the rotor and the inner peripheral wall of the stator is H1. Specifically, there is a minimum distance H1 between a point on the first arc segment of the rotor lamination and the inner peripheral wall of the stator. This is because the radius of the circle containing the first arc segment of the rotor lamination is relatively large, meaning the distance L1 between a point on the first arc segment and the center of the shaft hole is relatively large. The maximum distance between the outer peripheral wall of the rotor and the inner peripheral wall of the stator is H2. Specifically, there is a maximum distance between a point on the second arc segment of the rotor lamination and the inner peripheral wall of the stator. This is because the distance L2 between a point on the second arc segment of the rotor lamination and the center of the shaft hole is relatively small, meaning L2 is less than L1. Let the projection radius of the inner peripheral wall of the stator on the axial end face be R, i.e., the radius of the inner circle of the stator is R. Then, the minimum clearance H1 = R - L1, and the maximum clearance H2 = R - L2, so H2 is greater than H1.

[0048] Specifically, the difference between H1 and H2 not only directly determines the equivalent air gap length of the motor and affects the air gap magnetic field distribution, but also directly determines the salient pole ratio of the motor and affects the peak torque and high-speed performance of the motor. Specifically, the torque ripple of the motor mainly depends on the 5th, 7th, 11th, and 13th harmonics of the air gap magnetic field. The larger the difference between H1 and H2, the more sinusoidal the air gap magnetic field waveform, the smaller the harmonic amplitude of the motor, and the lower the torque ripple. However, the peak torque of the motor is also lower. The peak torque of the motor consists of reluctance torque and permanent magnet torque components. The permanent magnet torque of the motor is proportional to the amount of permanent magnets used, and the reluctance torque is proportional to the saliency ratio. The saliency ratio is the ratio of quadrature-axis inductance to direct-axis inductance, which is directly related to the difference between H1 and H2. With the amount of permanent magnets remaining constant, the difference between H1 and H2 can be reasonably allocated to ensure that the equivalent air gap length of the motor remains unchanged and the saliency ratio of the motor is not changed, thereby ensuring that the peak torque of the motor remains unchanged. Therefore, under the same peak torque, a solution with lower harmonic content, lower torque ripple, and better electromagnetic performance can be obtained.

[0049] In one possible design, the number of magnetic poles of the motor is P, the maximum distance between the center of the shaft hole in the rotor lamination and the outer periphery of the lamination body is L1, the minimum distance between the center of the shaft hole and the outer periphery of the lamination body is L2, and the radius of the arc containing the center of the second arc segment of the rotor lamination is r, where r satisfies the following formula: r = L1 - L2.

[0050] In this design, the number of magnetic poles of the motor is P. The maximum distance between the center of the shaft hole in the rotor lamination and the outer periphery of the lamination body is L1, and the minimum distance between the center of the shaft hole and the outer periphery of the lamination body is L2. The radius of the arc containing the center of the second arc segment of the rotor lamination is r, where r satisfies the above formula. This allows the center of the eccentric arc segment in the second arc segment to be located in a circle with the center of the shaft hole as the center and radius r. Of course, the center of the second arc segment cannot overlap with the center given by the shaft hole. By limiting the position of the center of the eccentric arc segment, the combination of the concentric first arc segment and the eccentric second arc segment can be more reasonable, taking into account the advantages of the full circular design and the pure eccentric design of the rotor lamination. Without changing the average air gap length of the motor and ensuring that the peak torque of the motor remains unchanged, the air gap magnetic field is effectively improved, resulting in increased air gap magnetic flux density and sinusoidal back EMF waveform, reduced harmonic ratio, and thus reduced torque pulsation, significantly reducing the vibration and noise of the motor.

[0051] According to a fifth aspect of the invention, a vehicle is provided, comprising the motor provided by any of the above-described designs.

[0052] The vehicle provided by this invention includes the motor provided by any of the above-described designs, and therefore possesses all the beneficial effects of that motor, which will not be repeated here. Additional aspects and advantages of this invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0053] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0054] Figure 1 A schematic diagram of the rotor lamination structure is shown in one embodiment of the present invention;

[0055] Figure 2 A schematic diagram of the rotor lamination structure is shown in another embodiment of the present invention;

[0056] Figure 3 It shows Figure 2 The image shown is a partial enlarged view of the rotor lamination at point A according to an embodiment of the present invention;

[0057] Figure 4 A schematic diagram of the motor structure is shown in one embodiment of the present invention;

[0058] Figure 5 It shows Figure 4 The image shown is a partial enlarged view of the motor at point B according to an embodiment of the present invention;

[0059] Figure 6Simulation curves of the average torque and torque ripple rate of the motor under the influence of the β / α ratio are shown in one embodiment of the present invention.

[0060] Figure 7 Simulation curves of the average torque and torque ripple rate of the motor under the influence of the difference between H2 and H1 are shown in one embodiment of the present invention.

[0061] Figure 8 The diagram shows the torque ripple distribution of a motor with a fully circular rotor lamination in the related technology at all speeds.

[0062] Figure 9 A torque ripple distribution diagram of a motor at full speed is shown in one embodiment of the present invention.

[0063] in, Figures 1 to 5 The correspondence between the reference numerals and component names in the attached drawings is as follows:

[0064] 10 rotor laminations,

[0065] 11-piece body, 110 arc segment,

[0066] 111 First arc segment,

[0067] 112 Second arc segment, 112a Left arc segment, 112b Right arc segment,

[0068] 12-axis holes,

[0069] 13 slots, 1301 first magnetic slot, 1302 second magnetic slot.

[0070] 130 Magnet slot, 131 First magnet slot, 132 Second magnet slot

[0071] 1311 First slot end,

[0072] 1312 Second slot end,

[0073] 1313 straight groove section,

[0074] 140 Auxiliary slot, 141 First auxiliary slot, 142 Second auxiliary slot.

[0075] 20 motors,

[0076] 21. Stator. Detailed Implementation

[0077] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0078] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0079] The following reference Figures 1 to 9 The invention describes a rotor lamination 10, a rotor core, a rotor, a motor 20, and a vehicle, provided according to some embodiments of the invention.

[0080] Example 1

[0081] According to a first aspect of the invention, a rotor lamination 10 is provided, such as Figure 1 and Figure 2 As shown, the rotor lamination 10 includes a lamination body 11, a shaft hole 12, and a plurality of slot groups 13, wherein the shaft hole 12 is disposed on the lamination body 11. The plurality of slot groups 13 are disposed on the lamination body 11, each slot group 13 including at least one magnetic slot, each magnetic slot including two magnet slots 130, each magnet slot 130 including a first slot end 1311 and a second slot end 1312 on an axial end face, the first slot end 1311 being arranged closer to the shaft hole 12 than the second slot end 1312. The outer periphery of the lamination body 11 includes an outer periphery section on the axial end face, the outer periphery section including a plurality of connected arcuate segments 110 corresponding to the plurality of slot groups 13, each arcuate segment 110 including a first arcuate segment 111 concentric with the shaft hole 12 and a second arcuate segment 112 discentric with the shaft hole 12.

[0082] The rotor lamination 10 provided by this invention includes a lamination body 11, a shaft hole 12, and multiple slot groups 13. The shaft hole 12 is formed on the lamination body 11, and the lamination body 11 is a magnet body. The shaft hole 12 is used to assemble the rotor shaft. Multiple slot groups 13 are arranged around the shaft hole 12 on the lamination body 11. It is worth noting that the structure of each of the multiple mounting parts can be the same or partially the same, and can be adjusted according to actual needs. Each slot group 13 includes at least one magnetic slot, and each magnetic slot includes two magnetic slots 130. Each magnetic slot 130 is used to assemble the permanent magnet of the rotor. Each magnetic slot 130 includes a first slot end 1311 and a second slot end 1312 on the axial end face. The first slot end 1311 is arranged closer to the shaft hole 12 than the second slot end 1312. When the distance between the first slot ends 1311 of the two magnetic slots 130 is not equal to the distance between the second slot ends 1312 of the two magnetic slots 130, the two magnetic slots 130 are arranged in a V-shape on the lamination body 11. The openings of the two V-shaped magnetic slots 130 face away from the shaft hole 12. Further, the outer periphery of the lamination body 11 includes an outer peripheral segment on the axial end face, and the outer peripheral segment is a closed line segment. The outer perimeter section includes multiple connected arc segments 110, with each arc segment 110 corresponding to one slot group 13. It is worth noting that the number of arc segments 110 and slot groups 13 are equal to the number of magnetic poles in the motor 20. By ensuring that each arc segment 110 includes at least a first arc segment 111 concentric with the shaft hole 12 and a second arc segment 112 discentric with the shaft hole 12, an unequal air gap that periodically varies along the circumference can be formed between the outer perimeter of the rotor and the inner perimeter of the stator 21 for the motor 20. This creates an alternation between the left arc segment 112a, the first arc segment 111, and the right arc segment 112b on the outer perimeter of the rotor lamination 10. This makes the operation of the motor 20 smoother, optimizes the rotor magnetic field distribution, effectively weakens the quadrature-direct axis armature reaction, and significantly improves the torque pulsation of the motor 20 while maintaining the peak torque of the motor 20. It also reduces the vibration and noise of the motor 20 during operation, improving user comfort. At the same time, it also reduces the stator 21 and rotor iron losses of motor 20 to a certain extent, which is beneficial to improving the efficiency of motor 20. Meanwhile, this application, through the combination of the first arc segment 111 and the second arc segment 112, takes into account the advantages of the full circular design and the pure eccentric design of rotor lamination 10. Without changing the average air gap length of motor 20 and ensuring that the peak torque of motor 20 remains unchanged, it effectively improves the air gap magnetic field, thereby increasing the air gap magnetic flux density and the sinusoidal nature of the back EMF waveform, reducing the proportion of harmonics, and thus reducing torque pulsation, significantly reducing the vibration and noise of motor 20.The present invention provides at least one V-shaped magnetic groove at each magnetic pole of the motor 20, and each arc segment 110 includes at least a concentric first arc segment 111 and a non-concentric second arc segment 112. This makes the overall structural layout of the rotor lamination 10 more reasonable. While ensuring the output torque of the motor 20, it can improve the air gap magnetic flux density distribution of the motor 20, reduce the harmonic content of the motor, thereby improving the torque pulsation and vibration noise of the motor 20, and achieving a high-performance motor 20 design.

[0083] Furthermore, since the motor 20 has 8 magnetic poles, the number of slot groups 13 is 8. Each slot group 13 includes two magnetic slots, and each magnetic slot includes two magnet slots 130. That is, each slot group 13 includes 4 magnet slots 130.

[0084] Furthermore, such as Figure 1 As shown, each of the two magnet slots 130 includes a straight slot segment 1313 connecting the first slot end 1311 and the second slot end 1312, and close to the other magnet slot 130. The straight slot segment 1313 includes a distal end away from the shaft hole 12. The polar arc angle α formed by the line connecting the distal ends of the two magnet slots 130 and the center of the shaft hole 12 is , and the central angle of the first arc segment 111 is β.

[0085] In this design, for the two magnet slots 130 in a magnetic groove, each magnet slot 130 includes two straight sections connecting the first slot end 1311 and the second slot end 1312. The straight section closer to the other magnet slot 130 is called the straight groove section 1313. That is, the two magnet slots 130 include a first magnet slot 131 and a second magnet slot 132. The first magnet slot 131 includes a straight groove section 1313 facing the second magnet slot 132, and the second magnet slot 132 includes a straight groove section 1313 facing the first magnet slot 131. Each straight groove section 1313 includes a distal end away from the shaft hole 12. The included angle formed by the lines connecting the distal ends of the first magnet slot 131 and the second magnet slot 132 to the center of the shaft hole 12 is the polar arc angle α.

[0086] Furthermore, the center of the circle containing the first arc segment 111 overlaps with the center of the shaft hole 12. The central angle β corresponding to the first arc segment 111 refers to the angle between the lines connecting the two endpoints of the first arc segment 111 to the center of the shaft hole 12. Specifically, the line connecting one endpoint of the first arc segment 111 to the center of the shaft hole 12 is denoted as the first line, and the line connecting the other endpoint of the first arc segment 111 to the center of the shaft hole 12 is denoted as the second line. The angle between the first line and the second line is the central angle β.

[0087] Furthermore, the ratio of the pole arc angle α to the central angle β has a significant impact on the peak torque, torque ripple, and air gap magnetic field of motor 20. A smaller β / α results in lower distortion of the air gap magnetic field waveform and lower torque ripple, but also lower torque and power. Conversely, a larger β / α leads to more severe distortion of the air gap magnetic field waveform and greater torque ripple. Therefore, a reasonable value for β / α is crucial for the performance of motor 20. By limiting the β / α ratio within the aforementioned range, multi-objective optimization of motor 20 torque, torque ripple, and air gap harmonics can be achieved. Without changing the torque of motor 20, the harmonic content of motor 20 can be effectively reduced, and the torque ripple of motor 20 can be improved. Specifically, the values ​​of β / α can be 0.35, 0.40, 0.45, 0.50, 0.55, 0.60, 0.65, 0.70, 0.75, 0.80, 0.85, 0.90, 0.95, 1.0, etc.

[0088] Furthermore, the straight section furthest from the other magnet slot 130 is the outer slot section. A clearance wall is provided between the outer slot section and the first slot end 1311 and / or the second slot end 1312. The permanent magnet is disposed within the magnet slot 130, and the permanent magnet can contact the clearance wall. The clearance wall can prevent dimensional interference between the magnet slot 130 and the permanent magnet from a manufacturing perspective, reducing the assembly difficulty of the permanent magnet. It is worth noting that the clearance wall is an arc-shaped wall. The arc-shaped wall can protrude towards the interior or exterior of the magnet slot 130. It is also worth noting that there are two arc-shaped walls, corresponding to the two ends of the permanent magnet, located on the outer slot section.

[0089] Furthermore, such as Figure 1 , Figure 2 and Figure 5 As shown, there are two second arc segments 112, which are connected to both sides of the first arc segment 111.

[0090] In this design, two second arc segments 112 are respectively connected to both sides of the first arc segment 111. Specifically, the two second arc segments 112 include a left arc segment 112a and a right arc segment 112b. That is, for one magnetic pole of the motor 20, the arc segment 110 includes the left arc segment 112a, the first arc segment 111, and the right arc segment 112b connected in sequence. For adjacent magnetic poles, the left arc segment 112a of one magnetic pole is connected to the right arc segment 112b of the adjacent magnetic pole, and the right arc segment 112b of one magnetic pole is connected to the left arc segment 112a of the adjacent magnetic pole. Furthermore, the center of the second arc segment 112 does not overlap with the center of the shaft hole 12. That is, the outer periphery of the lamination body 11 is formed by the combination of the first arc segment 111, which is concentrically positioned with the center of the shaft hole 12, and the second arc segment 112, which is eccentrically positioned. Therefore, for the motor 20, an unequal air gap that periodically varies along the circumference can be formed between the outer circumference of the rotor and the inner circumference of the stator 21. This creates an alternation between the left arc segment 112a, the first arc segment 111, and the right arc segment 112b on the outer circumference of the rotor lamination 10. This makes the operation of the motor 20 smoother, optimizes the rotor magnetic field distribution, effectively weakens the quadrature-axis and direct-axis armature reactions, and significantly improves the torque pulsation of the motor 20 while maintaining the peak torque of the motor 20. It also reduces the vibration and noise of the motor 20, improving user comfort. Simultaneously, it reduces the iron losses of the stator 21 and rotor of the motor 20 to a certain extent, which is beneficial to improving the efficiency of the motor 20. Meanwhile, this application combines the advantages of the full-circle design and the pure eccentric design of the rotor lamination 10 by combining the first arc segment 111 and the second arc segment 112. Without changing the average air gap length of the motor 20 and ensuring that the peak torque of the motor 20 remains unchanged, it effectively improves the air gap magnetic field, thereby increasing the air gap magnetic flux density and the sinusoidal nature of the back EMF waveform, reducing the proportion of harmonics, and thus reducing torque pulsation, significantly reducing the vibration noise of the motor 20.

[0091] Furthermore, such as Figure 1 , Figure 2 and Figure 5 As shown, the second arc segment 112 includes at least one eccentric arc segment.

[0092] In this design, each second arc segment 112 includes at least one eccentric arc segment. When the second arc segment 112 includes one eccentric arc segment, corresponding to one magnetic pole of the motor 20, the arc segment 110 includes one first arc segment 111 and two eccentric arc segments. When the second arc segment 112 includes two eccentric arc segments, corresponding to one magnetic pole of the motor 20, the arc segment 110 includes one first arc segment 111 and four eccentric arc segments. That is, the number of arc segments included in the arc segment 110 can be three, five, seven, etc. When there are multiple eccentric arc segments, for a single arc segment 110, multiple varying air gaps can be formed between the outer circumference of the rotor lamination 10 and the inner circumference of the stator 21. This facilitates the smooth operation of the motor 20 and optimizes the magnetic field distribution of the rotor with the lamination 10, effectively reducing the armature reaction of the quadrature and direct axes. While ensuring that the peak torque of the motor 20 remains unchanged, the torque pulsation of the motor 20 is significantly improved, the vibration and noise of the motor 20 are reduced, and the user's comfort is enhanced.

[0093] Example 2

[0094] Based on the foregoing embodiments, this embodiment describes the specific structure of each magnetic slot, and further, as follows: Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, there are at least two magnetic slots. The first slot ends 1311 of the two magnetic slots 130 of each magnetic slot are close to each other, and the second slot ends 1312 of the two magnetic slots 130 of each magnetic slot are far from each other. The two magnetic slots include a first magnetic slot 1301 and a second magnetic slot 1302. The first magnetic slot 1301 is located closer to the shaft hole 12 than the second magnetic slot 1302. The second magnetic slot 1302 forms a pole arc angle α. The first magnetic slot 1301 and the second magnetic slot 1302 are symmetrical with respect to the center line N of their respective magnetic poles.

[0095] In this design, corresponding to one magnetic pole of the motor 20, the slot group 13 includes two magnetic slots. In each magnetic slot, the first slot ends 1311 of the two magnetic slots 130 are close to each other, and the second slot ends 1312 of the two magnetic slots 130 are far from each other. That is, both magnetic slots are V-shaped slots, and the slot openings of the V-shaped slots formed by the two magnetic slots 130 in each magnetic slot face the outer periphery of the lamination body 11, i.e., away from the direction of the shaft hole 12. Further, the two magnetic slots include a first magnetic slot 1301 and a second magnetic slot 1302. The first magnetic slot 1301 is positioned closer to the shaft hole 12 than the second magnetic slot 1302. That is, the first slot ends 1311 of the magnetic slots 130 in the second magnetic slot 1302 are positioned closer to the shaft hole 12 than the first slot ends 1311 of the magnetic slots 130 in the second magnetic slot 1302. It is worth noting that when there are two magnetic slots, the pole arc angle α mentioned in the aforementioned design refers to the angle formed by the two magnetic slots 130 of the second magnetic slot 1302. That is, the two magnetic slots 130 of the second magnetic slot 1302 include a first magnetic slot 131 and a second magnetic slot 132. The first magnetic slot 131 includes a straight slot section 1313 facing the second magnetic slot 132, and the second magnetic slot 132 includes a straight slot section 1313 facing the first magnetic slot 131. Each straight slot section 1313 includes a distal end away from the shaft hole 12. The angle formed by the lines connecting the distal ends of the first magnetic slot 131 and the second magnetic slot 132 to the center of the shaft hole 12 is the pole arc angle α. Furthermore, both the first magnetic slot 1301 and the second magnetic slot 1302 are symmetrical with respect to the center line of their respective magnetic poles, thereby simplifying the structure of the motor 20 with the rotor lamination 10, making it easier to manufacture and reducing production costs.

[0096] Furthermore, such as Figure 3 and Figure 5 As shown, the angle formed by the extension lines of the straight groove segments 1313 of the two magnet grooves 130 in the first magnetic groove 1301 is the first opening angle, and the angle formed by the extension lines of the straight groove segments 1313 of the two magnet grooves 130 in the second magnetic groove 1302 is the second opening angle. The first opening angle is not equal to the second opening angle.

[0097] In this design, the angle formed by the extension lines of the straight slot segments 1313 of the two magnet slots 130 in the first magnetic slot 1301 is the first opening angle, and the angle formed by the extension lines of the straight slot segments 1313 of the two magnet slots 130 in the second magnetic slot 1302 is the second opening angle. The first opening angle is not equal to the second opening angle, which is beneficial to increasing the magnetic field strength under each magnetic pole, enabling magnetization. While increasing the output torque of the motor 20, it is also beneficial to further increase the ratio of the quadrature-axis inductance to the direct-axis inductance of the motor 20, thereby increasing the reluctance torque component and improving the field weakening speed extension capability of the motor 20. Specifically, the first opening angle is greater than the second opening angle, or the first opening angle is less than the second opening angle.

[0098] Furthermore, such as Figure 3 and Figure 5 As shown, the first opening angle is smaller than the second opening angle.

[0099] In this design, the first opening angle of the first magnetic groove 1301 near the shaft hole 12 is smaller than the second opening angle of the second magnetic groove 1302 away from the shaft hole 12, thereby increasing the magnetic field strength under each magnetic pole and achieving magnetic concentration. While increasing the output torque of the motor 20, it can further increase the ratio of the quadrature axis inductance to the direct axis inductance of the motor 20, thereby increasing the reluctance torque component and improving the field weakening speed extension capability of the motor 20.

[0100] Example 3

[0101] Based on the foregoing embodiments, this embodiment further explains the arrangement and specific structure of different arc segments in the arc segment 110, such as... Figure 3 and Figure 5 As shown, the first circular arc segment 111 is symmetrical with respect to the center line N of the magnetic pole. The two second circular arc segments 112 are also symmetrical with respect to the center line N of the magnetic pole.

[0102] In this design, the first arc segment 111 is symmetrical with respect to the centerline of its respective magnetic pole. Two second arc segments 112 are also symmetrical with respect to the centerline of their respective magnetic poles. That is, each arc segment 110 is symmetrical with respect to the centerline of its respective magnetic pole. This allows the outer periphery formed by the multiple arc segments 110 of the entire lamination body 11 to have a periodically unequal air gap with the inner circumference of the stator 21. Without changing the average air gap length of the motor 20 and ensuring that the peak torque of the motor 20 remains constant, this effectively improves the air gap magnetic field, increases the air gap magnetic flux density and the sinusoidal nature of the back EMF waveform, reduces the proportion of harmonics, and thus reduces torque pulsation, significantly reducing the vibration and noise of the motor 20. Furthermore, designing the arc segments 110 as symmetrical with respect to the centerline of the magnetic pole reduces the processing difficulty of the rotor lamination 10 and improves the product yield.

[0103] Furthermore, the arc lengths of the first circular arc segments 111 of the multiple arc segments 110 are all equal. The radii of the circles containing the first circular arc segments 111 of the multiple arc segments 110 are all equal.

[0104] In this design, the first arc segment 111 of the multiple arc segments 110 has the same arc length, which further ensures that there is a periodically unequal air gap between the outer circumference of the rotor and the inner circumference of the stator 21. This effectively improves the air gap magnetic field without changing the average air gap length of the motor 20 and ensuring that the peak torque of the motor 20 remains unchanged. Furthermore, the radii of the circles containing the first arc segments 111 of the multiple arc segments 110 are all equal, that is, the multiple first arc segments 111 are multiple arc segments on the same circle. This allows the projection of the maximum outer contour of the rotor lamination 10 onto the axial end face to have a regular shape, so that the rotor with the rotor lamination 10 requires a relatively regular space during high-speed rotation, that is, it is cylindrical, which facilitates the processing and manufacturing of the stator 21 that is compatible with it.

[0105] Furthermore, such as Figure 5 As shown, the center of the second arc segment 112 is located on the lamination body 11.

[0106] In this design, the center of the second arc segment 112 is located on the lamination body 11, meaning the second arc protrudes in the direction away from the shaft hole 12. In other words, the centers of the first arc segment 111 and the second arc segment 112 are both located on the lamination body 11. Therefore, the bending trends of the first arc segment 111 and the second arc segment 112 are similar, which can better control the formation of a periodically varying air gap between the outer circumference of the rotor and the inner circumference of the stator 21. This makes the operation of the motor 20 more stable, optimizes the rotor magnetic field distribution, effectively weakens the armature reaction of the quadrature and direct axes, and significantly improves the torque pulsation of the motor 20 while ensuring that the peak torque of the motor 20 remains unchanged. It also reduces the vibration and noise of the motor 20 during operation and improves the user's comfort.

[0107] Example 4

[0108] Based on the foregoing embodiments, this embodiment further describes the specific structure of the slot group 13, such as... Figure 4 and Figure 5 As shown, the groove group 13 further includes an auxiliary groove 140, which is disposed on the outer periphery of the lamination body 11.

[0109] In this design, each slot group 13 has an auxiliary slot 140, which is located on the outer periphery of the lamination body 11. The auxiliary slot 140 can effectively reduce the harmonic content in the air gap magnetic field of the motor 20, thereby improving the sinusoidality of the air gap magnetic flux density waveform, improving the torque ripple of the motor 20, reducing the radial force caused by harmonics, reducing the operating noise of the motor 20, and improving the vibration noise of the motor 20, thus improving user comfort. Furthermore, by providing recessed auxiliary slots 140 on the rotor lamination 10, this invention can also partially adjust the no-load back EMF waveform and radial force of the motor 20, reducing the maximum no-load line back EMF of the motor 20. It is worth noting that the torque ripple of the motor 20 largely depends on the non-sinusoidal nature of the air gap magnetic field. The higher the harmonic content in the air gap magnetic field, the worse the output torque waveform of the motor 20, the greater the ripple, and the greater the vibration noise.

[0110] Furthermore, such as Figure 5 As shown, there are multiple auxiliary slots 140, which are arranged at intervals and symmetrically arranged along the center line N of the magnetic pole.

[0111] In this design, each slot group 13 includes multiple auxiliary slots 140. For example, a slot group 13 can be provided with 4 auxiliary slots 140, and the multiple auxiliary slots 140 are arranged at intervals on the lamination body 11. The multiple auxiliary slots 140 of a slot group 13 are symmetrically arranged along the center line of the magnetic pole, and the number of auxiliary slots 140 is at least two, arranged in pairs.

[0112] Furthermore, such as Figure 5 As shown, the auxiliary groove 140 is an arc-shaped groove, specifically, the bottom of the auxiliary groove 140 is a circular arc bottom.

[0113] Furthermore, the auxiliary slot 140 includes two first auxiliary slots 141, which are symmetrically arranged on the first arc segment 111 along the center line of the magnetic pole. Furthermore, the auxiliary slot 140 also includes two second auxiliary slots 142, which are symmetrically arranged on the two second arc segments 112 along the center line of the magnetic pole.

[0114] In this design, the auxiliary slot 140 includes two first auxiliary slots 141 and two second auxiliary slots 142. The two first auxiliary slots 141 are symmetrically arranged on the first arc segment 111 along the center line of the magnetic pole, and the two second auxiliary slots 142 are arranged on the second arc segment 112 along the center line of the magnetic pole. The two second auxiliary slots 142 are respectively arranged on two different arc segments.

[0115] Furthermore, the depth of the first auxiliary slot 141 is greater than the depth of the second auxiliary slot 142. That is, for the concentric first arc segment 111, the depth of the first auxiliary slot 141 is larger, while for the eccentric second arc segment 112, the depth of the second auxiliary slot 142 is smaller. By combining the first auxiliary slot 141 and the second auxiliary slot 142 with different depths, the harmonic content in the air gap magnetic field can be further reduced, thereby improving the sinusoidal nature of the air gap magnetic flux density waveform. This can effectively improve torque pulsation and radial force. At the same time, the auxiliary slot 140 can also partially adjust the no-load back EMF waveform and reduce the maximum no-load line back EMF amplitude of the motor 20.

[0116] It is worth noting that the two first auxiliary slots 141 are of the same size, as are the two second auxiliary slots 142. Specifically, the two first auxiliary slots 141, located near the center line of the magnetic pole, can effectively optimize the air gap magnetic flux density waveform, improve the sinusoidal nature of the thin magnetic field in the air gap, reduce the radial electromagnetic force density of the motor 20, optimize the torque waveform of the motor 20, and reduce torque pulsation. Compared to the first auxiliary slots 141, the two second auxiliary slots 142, located away from the center line of the magnetic pole, can, in addition to helping reduce the torque pulsation of the motor 20, also reduce the maximum no-load line back EMF amplitude of the motor 20 while ensuring the peak torque of the motor 20.

[0117] In one embodiment, the auxiliary groove 140 may further include only the first auxiliary groove 141, that is, two first auxiliary grooves 141 are provided at the position corresponding to the first arc segment 111, without including the second auxiliary groove 142 provided on the second arc segment 112.

[0118] Furthermore, the depth of the first auxiliary groove 141 is greater than or equal to 0.5 mm and less than or equal to 0.9 mm. And / or, the depth of the second auxiliary groove 142 is greater than or equal to 0.1 mm and less than or equal to 0.7 mm.

[0119] In this design, the depth of the first auxiliary groove 141 meets the above-mentioned range. Specifically, the depth of the first auxiliary groove 141 can be 0.5mm, 0.55mm, 0.60mm, 0.65mm, 0.70mm, 0.75mm, 0.80mm, 0.85mm, 0.90mm, etc. The depth of the second auxiliary groove 142 meets the above-mentioned range. Specifically, the depth of the second auxiliary groove 142 can be 0.1mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm, 0.40mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, etc. When the depth of the first auxiliary groove 141 and the second auxiliary groove 142 meets the above-mentioned limit range, it can be ensured that the auxiliary groove 140 can effectively improve the performance of the motor 20, and the volume of the auxiliary groove 140 can be small, so as to avoid the auxiliary groove 140 causing a large change to the shape of the outer edge of the lamination body 11.

[0120] Example 5

[0121] According to a second aspect of the present invention, a rotor core is provided, comprising rotor laminations 10 provided by any of the above designs, wherein there are multiple rotor laminations 10, the multiple rotor laminations 10 are stacked, and multiple slot groups 13 of the multiple rotor laminations 10 are axially connected to form multiple slots.

[0122] The rotor core provided by the present invention includes the rotor lamination 10 provided by any of the above designs, and therefore has all the beneficial effects of the rotor lamination 10, which will not be repeated here.

[0123] It is worth noting that the rotor lamination 10 provided by the present invention includes a lamination body 11, a shaft hole 12, and a plurality of slot groups 13. The shaft hole 12 is formed on the lamination body 11, and the lamination body 11 is a magnet body. The shaft hole 12 is used to assemble the rotor shaft. The plurality of slot groups 13 are arranged around the shaft hole 12 on the lamination body 11. It is worth noting that the structure of each of the plurality of mounting parts can be the same or partially the same, and can be adjusted according to actual needs. Each slot group 13 includes at least one magnetic slot, and each magnetic slot includes two magnetic slots 130. Each magnetic slot 130 is used to assemble the permanent magnet of the rotor. Each magnetic slot 130 includes a first slot end 1311 and a second slot end 1312 on the axial end face. The first slot end 1311 is arranged closer to the shaft hole 12 than the second slot end 1312. When the distance between the first slot ends 1311 of the two magnetic slots 130 is not equal to the distance between the second slot ends 1312 of the two magnetic slots 130, the two magnetic slots 130 are arranged in a V-shape on the lamination body 11. The openings of the two V-shaped magnetic slots 130 face away from the shaft hole 12. Further, the outer periphery of the lamination body 11 includes an outer peripheral segment on the axial end face, and the outer peripheral segment is a closed line segment. The outer perimeter section includes multiple connected arc segments 110, with each arc segment 110 corresponding to one slot group 13. It is worth noting that the number of arc segments 110 and the number of slot groups 13 are equal to the number of magnetic poles of the motor 20. By ensuring that each arc segment 110 includes at least a first arc segment 111 concentric with the shaft hole 12, the air gap of the motor 20 at the first arc segment 111 can be made uniform, thereby increasing the air gap magnetic flux density and avoiding the phenomena of a large average air gap, significant decrease in motor torque and power, and insufficient motor output that occur when the outer perimeter section is composed of a purely eccentric circle. The present invention provides at least one V-shaped magnetic groove at each magnetic pole of the motor 20, and each arc segment 110 includes at least a concentric first circular arc segment 111, thereby making the overall structural layout of the rotor lamination 10 more reasonable. While ensuring the output torque of the motor 20, it can reduce the production cost of the motor 20, effectively improve the average air gap of the motor 20, increase the power density of the motor 20, and improve the torque pulsation of the motor 20, thereby achieving a high-performance and low-cost motor 20 design.

[0124] For the two magnet slots 130 in a magnetic groove, each magnet slot 130 includes two straight sections connecting the first slot end 1311 and the second slot end 1312. The straight section closer to the other magnet slot 130 is called the straight slot section 1313. That is, the two magnet slots 130 include a first magnet slot 131 and a second magnet slot 132. The first magnet slot 131 includes a straight slot section 1313 facing the second magnet slot 132, and the second magnet slot 132 includes a straight slot section 1313 facing the first magnet slot 131. Each straight slot section 1313 includes a distal end away from the shaft hole 12. The included angle formed by the lines connecting the distal ends of the first magnet slot 131 and the second magnet slot 132 to the center of the shaft hole 12 is the polar arc angle α.

[0125] Furthermore, the center of the circle containing the first arc segment 111 overlaps with the center of the shaft hole 12. The central angle β corresponding to the first arc segment 111 refers to the angle between the lines connecting the two endpoints of the first arc segment 111 to the center of the shaft hole 12. Specifically, the line connecting one endpoint of the first arc segment 111 to the center of the shaft hole 12 is denoted as the first line, and the line connecting the other endpoint of the first arc segment 111 to the center of the shaft hole 12 is denoted as the second line. The angle between the first line and the second line is the central angle β.

[0126] Furthermore, the ratio of the pole arc angle α to the central angle β has a significant impact on the peak torque, torque ripple, and air gap magnetic field of motor 20. A smaller β / α results in lower distortion of the air gap magnetic field waveform and lower torque ripple, but also lower torque and power. Conversely, a larger β / α leads to more severe distortion of the air gap magnetic field waveform and greater torque ripple. Therefore, a reasonable value for β / α is crucial for the performance of motor 20. By limiting the β / α ratio within the aforementioned range, multi-objective optimization of motor 20 torque, torque ripple, and air gap harmonics can be achieved. Without changing the torque of motor 20, the harmonic content of motor 20 can be effectively reduced, and the torque ripple of motor 20 can be improved.

[0127] Furthermore, the arc segment 110 also includes two second arc segments 112, which are respectively connected to both sides of the first arc segment 111. Specifically, the two second arc segments 112 include a left arc segment 112a and a right arc segment 112b. That is, for one magnetic pole of the motor 20, the arc segment 110 includes a left arc segment 112a, a first arc segment 111, and a right arc segment 112b connected in sequence. For adjacent magnetic poles, the left arc segment 112a of one magnetic pole is connected to the right arc segment 112b of the adjacent magnetic pole, and the right arc segment 112b of one magnetic pole is connected to the left arc segment 112a of the adjacent magnetic pole. Furthermore, the center of the second arc segment 112 does not overlap with the center of the shaft hole 12. That is, the outer periphery of the lamination body 11 is formed by the combination of the first arc segment 111, which is concentrically positioned with the center of the shaft hole 12, and the second arc segment 112, which is eccentrically positioned. Therefore, for the motor 20, an unequal air gap that periodically varies along the circumference can be formed between the outer circumference of the rotor and the inner circumference of the stator 21. This creates an alternation between the left arc segment 112a, the first arc segment 111, and the right arc segment 112b on the outer circumference of the rotor lamination 10. This makes the operation of the motor 20 smoother, optimizes the rotor magnetic field distribution, effectively weakens the quadrature-axis and direct-axis armature reactions, and significantly improves the torque pulsation of the motor 20 while maintaining the peak torque of the motor 20. It also reduces the vibration and noise of the motor 20, improving user comfort. Simultaneously, it reduces the iron losses of the stator 21 and rotor of the motor 20 to a certain extent, which is beneficial to improving the efficiency of the motor 20. Meanwhile, this application combines the advantages of the full-circle design and the pure eccentric design of the rotor lamination 10 by combining the first arc segment 111 and the second arc segment 112. Without changing the average air gap length of the motor 20 and ensuring that the peak torque of the motor 20 remains unchanged, it effectively improves the air gap magnetic field, thereby increasing the air gap magnetic flux density and the sinusoidal nature of the back EMF waveform, reducing the proportion of harmonics, and thus reducing torque pulsation, significantly reducing the vibration noise of the motor 20.

[0128] Example 6

[0129] According to a third aspect of the invention, a rotor is provided, comprising a rotor core provided by any of the above designs, and the rotor further comprising a plurality of permanent magnets respectively inserted into a plurality of slots.

[0130] The rotor provided by the present invention includes the rotor core provided by any of the above designs, and therefore has all the beneficial effects of the rotor core, which will not be repeated here.

[0131] Example 7

[0132] According to a fourth aspect of the invention, an electric motor 20 is provided, including a rotor provided by any of the above designs, the electric motor 20 further including a stator 21, the stator 21 including an axially extending assembly cavity, the rotor being located within the assembly cavity.

[0133] The motor 20 provided by the present invention includes the rotor provided by any of the above designs, and therefore has all the beneficial effects of the rotor, which will not be repeated here.

[0134] Specifically, the rotor lamination 10 includes a lamination body 11, a shaft hole 12, and multiple slot groups 13, wherein the shaft hole 12 is disposed on the lamination body 11. Multiple slot groups 13 are disposed on the lamination body 11, each slot group 13 including at least one magnetic slot, each magnetic slot including two magnet slots 130, each magnet slot 130 including a first slot end 1311 and a second slot end 1312 on an axial end face, the first slot end 1311 being closer to the shaft hole 12 than the second slot end 1312. The outer periphery of the lamination body 11 includes an outer periphery section on the axial end face, the outer periphery section including multiple connected arcuate segments 110 corresponding to the multiple slot groups 13, each arcuate segment 110 including a first arcuate segment 111 concentric with the shaft hole 12. Furthermore, each of the two magnet slots 130 includes a straight slot segment 1313 connecting the first slot end 1311 and the second slot end 1312, and close to the other magnet slot 130. The straight slot segment 1313 includes a distal end away from the shaft hole 12. The polar arc angle α formed by the line connecting the distal ends of the two magnet slots 130 and the center of the shaft hole 12 is , and the central angle of the first arc segment 111 is β. Furthermore, the arc segment 110 also includes two second arc segments 112, which are respectively connected to both sides of the first arc segment 111. The center of the second arc segment 112 does not overlap with the center of the shaft hole 12. This application combines the advantages of the full-circle design and the pure eccentric design of the rotor lamination 10. Without changing the average air gap length of the motor 20 and ensuring that the peak torque of the motor 20 remains unchanged, it effectively improves the air gap magnetic field, thereby increasing the air gap magnetic flux density and the sinusoidal nature of the back EMF waveform, reducing the proportion of harmonics, and thus reducing torque pulsation, significantly reducing the vibration noise of the motor 20. The full-circle design of the rotor lamination 10 means that the outer periphery of the lamination body 11 of the rotor lamination 10 is a full circle. The pure eccentric design of the rotor lamination 10 means that the outer periphery of the lamination body 11 of the rotor lamination 10 includes multiple connected arc segments, and the center of the circle containing each arc segment does not overlap with the center of the shaft hole 12.

[0135] Furthermore, such as Figure 5 As shown, the minimum distance between the outer peripheral wall of the rotor and the inner peripheral wall of the stator 21 is H1, and the maximum distance between the outer peripheral wall of the rotor and the inner peripheral wall of the stator 21 is H2, wherein 0.15mm≤H2-H1≤0.35mm.

[0136] In this design, the minimum distance between the outer peripheral wall of the rotor and the inner peripheral wall of the stator 21 is H1. Specifically, there is a minimum distance H1 between a point in the first arc segment 111 of the rotor lamination 10 and the inner peripheral wall of the stator 21. This is because, as Figure 4 As shown, the radius of the circle containing the first arc segment 111 of the rotor lamination 10 is relatively large, meaning the distance L1 between a point on the first arc segment 111 and the center of the shaft hole 12 is relatively large. The maximum distance between the outer peripheral wall of the rotor and the inner peripheral wall of the stator 21 is H2. Specifically, there is a maximum gap between a point on the second arc segment 112 of the rotor lamination 10 and the inner peripheral wall of the stator 21. This is because the distance L2 between a point on the second arc segment 112 of the rotor lamination 10 and the center of the shaft hole 12 is relatively small, meaning L2 is less than L1. Let the projection radius of the inner peripheral wall of the stator 21 on the axial end face be R, that is, the radius of the inner circle of the stator 21 is R, then the minimum gap H1 = R - L1, and the maximum gap H2 = R - L2, so H2 is greater than H1.

[0137] Specifically, the difference between H1 and H2 not only directly determines the equivalent air gap length of motor 20 and affects the air gap magnetic field distribution, but also directly determines the salient pole ratio of motor 20 and affects the peak torque and high-speed performance of motor 20. Specifically, the torque ripple of motor 20 mainly depends on the 5th, 7th, 11th, and 13th harmonics of the air gap magnetic field. The larger the difference between H1 and H2, the more sinusoidal the air gap magnetic field waveform, the smaller the harmonic amplitude of motor 20, and the lower the torque ripple. However, the peak torque of motor 20 is also lower. The peak torque of motor 20 consists of reluctance torque component and permanent magnet torque component. The permanent magnet torque of motor 20 is proportional to the amount of permanent magnet used, and the reluctance torque is proportional to the saliency ratio. The saliency ratio is the ratio of quadrature axis inductance to direct axis inductance, which is directly related to the difference between H1 and H2. With the amount of permanent magnet used unchanged, the difference between H1 and H2 can be reasonably allocated to ensure that the equivalent air gap length of motor 20 remains unchanged and the saliency ratio of motor 20 is not changed, thereby ensuring that the peak torque of motor 20 remains unchanged. Therefore, under the same peak torque, a solution with lower harmonic content, lower torque ripple, and better electromagnetic performance can be obtained. Specifically, the values ​​of H2-H1 can be 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm, etc.

[0138] Furthermore, such as Figure 1 , Figure 4 and Figure 5 As shown, the number of magnetic poles of motor 20 is P, the maximum distance between the center of the shaft hole 12 in the rotor lamination 10 of motor 20 and the outer periphery of the lamination body 11 is L1, the minimum distance between the center of the shaft hole 12 and the outer periphery of the lamination body 11 is L2, and the radius of the arc where the center of the second arc segment 112 of rotor lamination 10 is located is r, where r satisfies the following formula: r=L1-L2.

[0139] In this design, the number of magnetic poles of the motor 20 is P. The maximum distance between the center of the shaft hole 12 in the rotor lamination 10 of the motor 20 and the outer periphery of the lamination body 11 is L1, and the minimum distance between the center of the shaft hole 12 and the outer periphery of the lamination body 11 is L2. The radius of the arc containing the center of the second arc segment 112 of the rotor lamination 10 is r, where r satisfies the above formula. Therefore, the center of the eccentric arc segment in the second arc segment 112 can be located within a circle with the center of the shaft hole 12 as its center and radius r. Of course, the circle of the second arc segment 112... The center cannot overlap with the center of the circle given by the shaft hole 12. By limiting the center position of the eccentric arc segment, the combination of the concentric first arc segment 111 and the eccentric second arc segment 112 can be more reasonable. It takes into account the advantages of the rotor lamination 10's full circle design and pure eccentric design. Without changing the average air gap length of the motor 20 and ensuring that the peak torque of the motor 20 remains unchanged, it effectively improves the air gap magnetic field, increases the air gap magnetic flux density and the sinusoidal nature of the back EMF waveform, reduces the proportion of harmonics, and thus reduces torque pulsation, significantly reducing the vibration noise of the motor 20.

[0140] In a specific embodiment, taking an 8-pole, 48-slot motor 20 as an example, the rotor laminations 10 include two first auxiliary slots 141 and two second auxiliary slots 142. The magnetic slots include a V-shaped first magnetic slot 1301 and a second magnetic slot 1302. After determining the value of α, in this example, α = 16° is taken. While ensuring that other parameters of the motor 20 remain unchanged, the ratio of β / α is taken as 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, 0.95, 1.05, 1.15, and 1.25. Figure 6 The figure shows the curves of the average peak torque and torque ripple rate of motor 20 as a function of β / α. It can be seen that when the value of β / α is in the range of 0.35 to 1, the peak torque and torque ripple rate of motor 20 are at the optimal level.

[0141] Furthermore, while keeping other parameters of motor 20 unchanged, the difference between H1 and H2 is changed. Here, H2 = 0.65mm, and the difference between H1 and H2 is 0.05mm, 0.15mm, 0.25mm, 0.35mm, 0.45mm, and 0.55mm. Figure 7 The curves showing the variation of average peak torque and torque ripple rate with the difference between H2 and H1 are given. It can be seen that when the value of H2-H1 is in the range of 0.15mm to 0.35mm, the peak torque and torque ripple rate of motor 20 are at the optimal level.

[0142] Furthermore, when the ratio of β to α satisfies 0.35 ≤ β / α < 1, and the difference between H2 and H1 is between 0.15 mm and 0.35 mm, a reasonable combination of β and H1, H2 is selected within this range. For example, in this embodiment, given parameter α = 16°, β = 13°, H1 = 0.7 mm, and H2 = 0.9 mm are selected. Table 1 below shows the electromagnetic parameters of motor 20 at the peak torque point. As can be seen from Table 1, compared with the rotor circular design, this technique reduces the distortion rate of the air gap magnetic flux density waveform of motor 20 and weakens the torque pulsation of motor 20 without changing the average air gap length of motor 20 and ensuring that the peak torque of motor 20 remains unchanged. This effectively improves the torque performance and vibration noise performance of motor 20.

[0143] Table 1

[0144] Electromagnetic parameters Conventional round design The present application design Equivalent air gap length (mm) 0.75 mm 0.75 mm Magnetic flux waveform distortion rate (%) 26.6％ 18.7％ Average electromagnetic torque (Nm) 391.6 391.4 Torque pulsation rate (%) 4.7％ 3.15％

[0145] Figure 8 This is a torque pulsation distribution diagram for a motor with a traditional circular design across the entire speed range. Figure 9 The torque pulsation distribution diagram of the motor 20 designed for this application is shown in the comparison. It can be seen that the torque pulsation decreases across the entire speed range. The torque pulsation in the speed range of 8000rpm-16000rpm shows a significant decrease, with the maximum decrease reaching 87.5%. The torque pulsation in the high-speed range is controlled within 8.5%.

[0146] Example 8

[0147] According to a fifth aspect of the invention, a vehicle is provided, comprising a motor 20 provided by any of the above-described designs.

[0148] The vehicle provided by the present invention includes the motor 20 provided by any of the above designs, and therefore has all the beneficial effects of the motor 20, which will not be repeated here.

[0149] It is worth noting that the vehicle can be a new energy vehicle. New energy vehicles include pure electric vehicles, range-extended electric vehicles, hybrid electric vehicles, fuel cell electric vehicles, hydrogen engine vehicles, etc. Furthermore, the motor 20 provided in any of the above designs can serve as the vehicle's drive motor 20. Specifically, the drive motor 20 can independently start the vehicle's functional devices. Alternatively, the drive motor 20 can cooperate with other drive devices on the vehicle to ensure the normal operation of the vehicle's functional devices. The vehicle's functional devices can be any one or any combination of the following: wheels, air conditioner, lighting components, etc.

[0150] In this invention, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0151] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0152] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rotor lamination, characterized by The rotor core includes: a core body; an axial hole arranged on the core body; a plurality of slot groups arranged on the core body, each of the slot groups including at least one magnetic slot, each of the magnetic slots including two magnet slots, each of the magnet slots including a first slot end and a second slot end on an axial end surface, the first slot end being arranged closer to the axial hole than the second slot end; wherein an outer periphery of the core body includes an outer periphery section on the axial end surface, the outer periphery section including a plurality of connected arc sections corresponding to the plurality of slot groups, each of the arc sections including at least a first circular arc section concentric with the axial hole and a second circular arc section non-concentric with the axial hole; either of the two magnet slots comprises a straight slot section connected between the first slot end and the second slot end and adjacent to the other of the two magnet slots, the straight slot section comprising a distal end distal to the axis hole, a line between the distal ends of the two magnet slots and the circle center of the axis hole forming a polar arc angle a, a circle center angle of the first circular arc section being β, wherein, the number of the second circular arc sections is two, and the two second circular arc sections are connected on both sides of the first circular arc section, respectively; the number of the at least one magnetic slot is two, the first slot ends of the two magnet slots of each of the magnetic slots are close to each other, and the second slot ends of the two magnet slots of each of the magnetic slots are away from each other; the two magnetic slots include a first magnetic slot and a second magnetic slot, the first magnetic slot is arranged closer to the axial hole than the second magnetic slot, and the second magnetic slot forms a pole arc angle α, wherein the first magnetic slot and the second magnetic slot are symmetrical with respect to a center line of a magnetic pole; the first circular arc section is symmetrical with respect to the center line of the magnetic pole; the two second circular arc sections are symmetrical with respect to the center line of the magnetic pole; the arc lengths of the first circular arc sections of the plurality of arc sections are equal; the radii of the circles on which the first circular arc sections of the plurality of arc sections are located are equal.

2. The rotor core according to claim 1, wherein the second circular arc section includes at least one eccentric circular arc section.

3. The rotor core according to claim 1, wherein an included angle formed by the extensions of the straight slot sections of the two magnet slots in the first magnetic slot is a first opening angle, an included angle formed by the extensions of the straight slot sections of the two magnet slots in the second magnetic slot is a second opening angle, and the first opening angle is not equal to the second opening angle.

4. The rotor core according to claim 3, wherein the first opening angle is smaller than the second opening angle.

5. The rotor core according to any one of claims 1 to 4, wherein the center of the second circular arc section is located on the core body.

6. The rotor lamination of any one of claims 1 to 4, wherein, The slot group further includes: an auxiliary slot arranged on the outer periphery of the core body.

7. The rotor core according to claim 6, wherein the number of the auxiliary slots is a plurality, the plurality of auxiliary slots are arranged at intervals, and the plurality of auxiliary slots are arranged symmetrically with respect to the center line of the magnetic pole.

8. The rotor lamination of claim 7, wherein, The auxiliary slot includes: two first auxiliary slots arranged symmetrically with respect to the center line of the magnetic pole on the first circular arc section; and / or two second auxiliary slots arranged symmetrically with respect to the center line of the magnetic pole on the two second circular arc sections, respectively.

9. The rotor core according to claim 8, wherein the slot depth of the first auxiliary slot is greater than or equal to 0.5 mm and less than or equal to 0.9 mm; and / or the slot depth of the second auxiliary slot is greater than or equal to 0.1 mm and less than or equal to 0.7 mm.

10. A rotor core characterized by, Comprising: The rotor sheet as claimed in any one of claims 1 to 9, a plurality of the rotor sheets are stacked, a plurality of slot groups of the plurality of rotor sheets are formed into a plurality of insertion slots along an axial direction.

11. A rotor characterized by, Comprising: The rotor core as claimed in claim 10; A plurality of permanent magnets are respectively inserted into the plurality of insertion slots.

12. An electric machine characterized by Comprising: The rotor as claimed in claim 11; A stator comprising an assembly cavity penetrating along an axial direction, and the rotor is located in the assembly cavity.

13. The motor of claim 12, wherein: A minimum distance between the outer circumferential wall of the rotor and the inner circumferential wall of the stator is H1, and a maximum distance between the outer circumferential wall of the rotor and the inner circumferential wall of the stator is H2, wherein 0.15mm≤H2-H1≤0.35mm.

14. The motor of claim 12, wherein: A number of magnetic poles of the motor is P, a maximum distance between a center of an axial hole of a rotor sheet of the rotor and an outer circumferential edge of a sheet body is L1, a minimum distance between the center of the axial hole and the outer circumferential edge of the sheet body is L2, and a radius of a circular arc where a center of a second circular arc segment of the rotor sheet is located is r, wherein r satisfies the following formula: r=L1-L2.

15. A vehicle characterized by comprising: Comprising: The motor as claimed in any one of claims 12 to 14.

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