Electric machines and vehicles

Abstract

The application discloses a motor and a vehicle, the motor comprising: a rotor assembly, the rotor assembly comprising a rotor core and a plurality of permanent magnets, the rotor core being provided with a plurality of mounting slots, each mounting slot being provided with a permanent magnet, and the plurality of permanent magnets comprising permanent magnets made of at least two different materials; and a stator assembly, the stator assembly being arranged outside the rotor assembly, the stator assembly comprising a stator core, the stator core being formed by a plurality of stator laminations stacked along an axial direction, each stator lamination being provided with a plurality of stator slots arranged at intervals in a circumferential direction, each stator slot having a slot opening located on an inner wall of the stator core, and in the axial direction of the stator core, the plurality of stator slots of any two adjacent stator laminations are arranged one by one in a facing manner, and the slot openings of the stator slots arranged in the facing manner of any two adjacent stator laminations are arranged in a staggered manner. Thus, the cogging torque generated during rotation of the motor can be reduced, the stability of the motor can be improved, the demagnetization resistance of the permanent magnets can be improved, and the cost can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric machines, and in particular to an electric machine and a vehicle having the same. BACKGROUND

[0002] Permanent magnet synchronous machines are widely used in electric vehicles. The electric machine is one of the cores of the electric drive system, and the comprehensive performance of the electric machine directly affects the performance of the electric vehicle. At present, there are still technical bottlenecks in the development of high overload capacity and anti-demagnetization permanent magnet synchronous machines (PMSM) for electric vehicles. There are a series of problems such as large cogging torque, high cost, poor load torque, large eddy current loss, etc. There is room for improvement. SUMMARY

[0003] The present application aims to at least solve one of the technical problems existing in the prior art. To this end, the present application provides an electric machine, which has small cogging torque during rotation, high stability, good anti-demagnetization performance, and low cost.

[0004] The electric machine according to the embodiments of the present application comprises: a rotor assembly, the rotor assembly comprising a rotor core and a plurality of permanent magnets, the rotor core being provided with a plurality of mounting grooves, each of the mounting grooves being provided with the permanent magnet, and the plurality of permanent magnets comprising permanent magnets of at least two different materials; and a stator assembly, the stator assembly being arranged outside the rotor assembly, the stator assembly comprising a stator core, the stator core being stacked by a plurality of stator laminations along an axial direction, each of the stator laminations being provided with a plurality of stator slots arranged at intervals along a circumferential direction, each of the stator slots having a slot opening located at an inner wall of the stator core, and in the axial direction of the stator core, the plurality of stator slots of any two adjacent stator laminations are arranged in one-to-one correspondence, and the slot openings of the stator slots of any two adjacent stator laminations are arranged in a staggered manner.

[0005] The electric machine according to the embodiments of the present application, by arranging the slot openings of the stator slots of any two adjacent stator laminations of the stator assembly in a staggered manner, can make at least part of the cogging torques of the two adjacent stator laminations cancel each other out, thereby reducing the cogging torque of the electric machine, reducing the torque fluctuation and the shaking caused by the torque fluctuation, improving the control accuracy of the electric machine, and improving the NVH performance of the electric machine. In addition, by arranging the plurality of permanent magnets to comprise permanent magnets of at least two different materials, the anti-demagnetization performance of the permanent magnets can be improved, and the cost of the rotor assembly can be reduced, thereby reducing the cost of the electric machine.

[0006] The electric machine according to some embodiments of the present application, on the same cross section of the stator core, the normal projections of the stator slots of any two adjacent stator laminations arranged in correspondence are arranged in a symmetrical manner.

[0007] The electric machine according to some embodiments of the present application, the plurality of permanent magnets comprise ferrite and rare earth permanent magnet materials.

[0008] The motor according to some embodiments of the present application, on the same cross section of the rotor core, the permanent magnet arranged in the mounting slot with the largest area is the ferrite.

[0009] The motor according to some embodiments of the present application, at least one of the mounting slots is arranged with the segmented permanent magnet.

[0010] The motor according to some embodiments of the present application, the length of the segmented permanent magnet in the same mounting slot is different.

[0011] The motor according to some embodiments of the present application, on the same cross section of the stator core, the width of the slot opening of the stator slot is W, and the stator core satisfies the following relationship: 0.13mm≤W≤5.07mm.

[0012] The motor according to some embodiments of the present application, the stator core satisfies the following relationship: 0.63mm≤W≤5mm.

[0013] The motor according to some embodiments of the present application, on the same cross section of the stator core, the first connecting line is the line connecting the center of the width direction of the slot opening of the stator slot and the center of the stator core, the second connecting line is the line connecting the center of the width direction of the slot opening of the stator slot and the center of the stator core, the included angle of the first connecting line and the second connecting line is α, and the stator core satisfies the following relationship: 0.1°≤α≤5°.

[0014] The motor according to some embodiments of the present application, the stator core satisfies the following relationship: 1°≤α≤3°.

[0015] The motor according to some embodiments of the present application, on the same cross section of the stator core, the width of the slot opening of the stator slot is W, the first connecting line is the line connecting the center of the width direction of the slot opening of the stator slot and the center of the stator core, the second connecting line is the line connecting the center of the width direction of the slot opening of the stator slot and the center of the stator core, the included angle of the first connecting line and the second connecting line is α, and the stator core satisfies the following relationship:

[0016] The motor according to some embodiments of the present application, the stator core satisfies the following relationship:

[0017] The motor according to some embodiments of the present application, the plurality of mounting slots comprises a first mounting slot, a second mounting slot and a third mounting slot, the first mounting slot is located at the radial outer side of the third mounting slot, the second mounting slot extends along the radial direction of the rotor core, and one first mounting slot and one third mounting slot are arranged between two adjacent second mounting slots; the corresponding first mounting slot arranged permanent magnet comprises segmented first permanent magnet and second permanent magnet, the corresponding second mounting slot arranged permanent magnet comprises segmented third permanent magnet and fourth permanent magnet, and the corresponding third mounting slot arranged permanent magnet comprises segmented fifth permanent magnet and sixth permanent magnet.

[0018] The motor according to some embodiments of the present application, in the circumferential direction of the rotor core, the ratio of the length of the first permanent magnet and the length of the second permanent magnet is greater than or equal to 1 / 7 and less than or equal to 1 / 2, and the ratio of the length of the fifth permanent magnet and the length of the sixth permanent magnet is greater than or equal to 1 / 7 and less than or equal to 1 / 2; in the radial direction of the rotor core, the ratio of the length of the third permanent magnet and the length of the fourth permanent magnet is greater than or equal to 1 / 7 and less than or equal to 1 / 2.

[0019] The motor according to some embodiments of the present application, in the radial direction of the rotor core, the width of the first permanent magnet and the second permanent magnet is in the range of 2mm-7mm, and the width of the fifth permanent magnet and the sixth permanent magnet is in the range of 5mm-12mm; in the circumferential direction of the rotor core, the width of the third permanent magnet and the fourth permanent magnet is in the range of 2mm-7mm.

[0020] The motor according to some embodiments of the present application, on the same cross section of the rotor core, the minimum distance between the first mounting slot and the outer peripheral wall of the rotor core is L1, the minimum distance between the second mounting slot and the outer peripheral wall of the rotor core is L2, and the minimum distance between the third mounting slot and the outer peripheral wall of the rotor core is L3, and the rotor core satisfies the following relationship:

[0021] The motor according to some embodiments of the present application, the rotor core satisfies the following relationship:

[0022] The motor according to some embodiments of the present application, on the same cross section of the rotor core, the line between the geometric center of the first permanent magnet and the center of the rotor core is a third line, the length of the third line is L4, the line between the geometric center of the second permanent magnet and the center of the rotor core is a fourth line, the length of the fourth line is L5, the line between the geometric center of the third permanent magnet and the center of the rotor core is a fifth line, the length of the fifth line is L6, the rotor core satisfies the following relationship:

[0023] The motor according to some embodiments of the present application, the rotor core satisfies the following relationship:

[0024] The motor according to some embodiments of the present application, on the same cross section of the rotor core, the line between the geometric center of the first permanent magnet and the center of the rotor core is a third line, the length of the third line is L4, the line between the geometric center of the second permanent magnet and the center of the rotor core is a fourth line, the length of the fourth line is L5, the line between the geometric center of the third permanent magnet and the center of the rotor core is a fifth line, the length of the fifth line is L6, the rotor core satisfies the following relationship:

[0025] The motor according to some embodiments of the present application, the rotor core satisfies the following relationship:

[0026] The motor according to some embodiments of the present application, on the same cross section of the stator core, the width of the slot opening of the stator slot is W, the center line of the width direction of the slot opening of the stator slot and the center of the stator core is the first connecting line, the connecting line of the width center of the stator slot and the center of the stator core is the second connecting line, the included angle of the first connecting line and the second connecting line is α; on the same cross section of the rotor core, the connecting line between the geometric center of the third permanent magnet and the center of the rotor core is the fifth connecting line, the length of the fifth connecting line is L6, the included angle between the fifth connecting line and the d-axis is α3, the connecting line between the geometric center of the fourth permanent magnet and the center of the rotor core is the sixth connecting line, the length of the sixth connecting line is L7, the included angle between the sixth connecting line and the d-axis is α4, the width of the second permanent magnet is W2, the width of the sixth permanent magnet is W6, and the rotor core satisfies the following relationship:

[0027] The motor according to some embodiments of the present application, the rotor core satisfies the following relationship:

[0028] The motor according to some embodiments of the present application, on the same cross section of the stator core, the width of the slot opening of the stator slot is W, the center line of the width direction of the slot opening of the stator slot and the center of the stator core is the first connecting line, the connecting line of the width center of the stator slot and the center of the stator core is the second connecting line, the included angle of the first connecting line and the second connecting line is α; on the same cross section of the rotor core, the connecting line between the geometric center of the third permanent magnet and the center of the rotor core is the fifth connecting line, the length of the fifth connecting line is L6, the included angle between the fifth connecting line and the d-axis is α3, the connecting line between the geometric center of the fourth permanent magnet and the center of the rotor core is the sixth connecting line, the length of the sixth connecting line is L7, the included angle between the sixth connecting line and the d-axis is α4, the width of the second permanent magnet is W2, the width of the sixth permanent magnet is W6, and the rotor core satisfies the following relationship:

[0029] The motor according to some embodiments of the present application, the rotor core satisfies the following relationship:

[0030] The present application also provides a vehicle.

[0031] The vehicle according to the embodiments of the present application comprises the motor according to any of the above embodiments.

[0032] According to the vehicle of the embodiment of the present application, by setting the slot opening of the facingly arranged stator slots of any two adjacent stator laminations of the stator assembly to be staggered, the cogging torque of at least part of the teeth of the two adjacent stator laminations can be offset, thereby reducing the cogging torque of the motor, reducing the torque fluctuation and the shaking caused by the torque fluctuation, improving the control accuracy of the motor, improving the NVH performance of the motor, and by setting the plurality of permanent magnets to include at least two permanent magnets made of different materials, the demagnetization resistance of the permanent magnets can be improved, the cost of the rotor assembly can be reduced, thereby reducing the cost of the motor, and the practicability of the vehicle is improved.

[0033] Additional aspects and advantages of the present application will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following and / or can be learned by practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0034] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood by considering the following detailed description, from which the above-mentioned aspects and advantages of the present application will become apparent, and in part will be realized.

[0035] Figure 1 is a schematic diagram of a motor according to an embodiment of the present application;

[0036] Figure 2 is a partial schematic diagram of a stator lamination according to an embodiment of the present application;

[0037] Figure 3 is a partial schematic diagram of a stator lamination according to another embodiment of the present application;

[0038] Figure 4 is a schematic diagram of a rotor assembly according to an embodiment of the present application;

[0039] Figure 5 is a partial schematic diagram of a rotor assembly according to an embodiment of the present application;

[0040] Figure 6 is a partial schematic diagram of a rotor assembly according to an embodiment of the present application;

[0041] Figure 7 is a partial schematic diagram of a rotor assembly according to an embodiment of the present application;

[0042] Figure 8 is a partial schematic diagram of a rotor assembly according to another embodiment of the present application;

[0043] Figure 9 is a waveform diagram of cogging torque when the slot opening of the stator slots of adjacent stator laminations is set to be staggered according to an embodiment of the present application;

[0044] Figure 10is a waveform diagram of cogging torque when the slot openings of the stator slots of the adjacent stator laminations are oppositely arranged using mixed magnetic steel;

[0045] Figure 11 is a waveform diagram of cogging torque when the slot openings of the stator slots of the adjacent stator laminations are oppositely arranged using Nd-Fe-B magnetic steel;

[0046] Figure 12 is a waveform diagram of cogging torque when the slot openings of the stator slots of the adjacent stator laminations are oppositely arranged using Nd-Fe-B magnetic steel.

[0047] Reference numerals:

[0048] Motor 100,

[0049] Rotor assembly 10, rotor core 11, first mounting slot 111, second mounting slot 112, third mounting slot 113,

[0050] Permanent magnet 12, first permanent magnet 121, second permanent magnet 122, third permanent magnet 123, fourth permanent magnet 124, fifth permanent magnet 125, sixth permanent magnet 126,

[0051] Stator assembly 20, stator core 21, coil 22, stator lamination 23, stator slot 24, slot opening 241. DETAILED DESCRIPTION

[0052] Embodiments of the present application are described in detail below with reference to the attached drawings, which are given by way of example and thus do not limit the present application. In the drawings, like reference numerals indicate like elements throughout the drawings. The embodiments described below are examples of how the present application can be implemented, and are not intended to limit the present application.

[0053] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0054] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0055] Next, referring to the drawings, the motor 100 according to the embodiment of the present application is described.

[0056] As shown in the drawings, Figures 1-3 The motor 100 according to the embodiment of the present application includes a rotor assembly 10 and a stator assembly 20. The rotor assembly 10 includes a rotor core 11 and a plurality of permanent magnets 12. The rotor core 11 is provided with a plurality of mounting grooves, and each mounting groove is provided with a permanent magnet 12. The plurality of permanent magnets 12 includes at least two permanent magnets 12 made of different materials. The stator assembly 20 is sleeved outside the rotor assembly 10. The stator assembly 20 includes a stator core 21. The stator core 21 is formed by axially stacking a plurality of stator laminations 23. Each stator lamination 23 is provided with a plurality of stator slots 24 arranged at intervals in the circumferential direction. Each stator slot 24 has a slot opening 241 located on the inner wall of the stator core 21. In the axial direction of the stator core 21, the plurality of stator slots 24 of any two adjacent stator laminations 23 are arranged in one-to-one correspondence, and the slot openings 241 of the stator slots 24 of any two adjacent stator laminations 23 are arranged in a staggered manner.

[0057] Therefore, by arranging the slot openings 241 of the stator slots 24 of any two adjacent stator laminations 23 of the stator assembly 20 in a staggered manner, the tooth slot torques of the adjacent two stator laminations 23 can be at least partially offset, thereby reducing the tooth slot torque of the motor 100, reducing the torque fluctuation and the shaking caused by the torque fluctuation, improving the control accuracy of the motor 100, and improving the NVH performance of the motor 100. By arranging the plurality of permanent magnets 12 to include at least two permanent magnets 12 made of different materials, the demagnetization resistance of the permanent magnets 12 can be improved, and the cost of the rotor assembly 10 can be reduced, thereby reducing the cost of the motor 100.

[0058] As shown in the drawings, Figures 8-12 Figure 9 is a waveform diagram of the tooth slot torque when the motor 100 according to the embodiment of the present application adopts mixed magnetic steel and the slot openings 241 of the stator slots 24 of adjacent stator laminations 23 are arranged in a staggered manner. The value is 1.423 Nm. Figure 10 is a waveform diagram of the tooth slot torque when the motor 100 according to the embodiment of the present application adopts mixed magnetic steel and the slot openings 241 of the stator slots 24 of adjacent stator laminations 23 are arranged in a relative manner. The value is 1.6673 Nm. Figure 11 ​is a schematic diagram of the cogging torque waveform when the slot openings 241 of the stator slots 24 of the adjacent stator laminations 23 are oppositely arranged, and the value is 3.4656 Nm; Figure 12 is a schematic diagram of the cogging torque waveform when the slot openings 241 of the stator slots 24 of the adjacent stator laminations 23 are misaligned, and the value is 2.694 Nm. The value of the cogging torque cannot be directly obtained from the figure, but it is the relevant data recorded during the experiment. However, for those skilled in the art, the relevant cogging torque value can be obtained from the waveform without any doubt.

[0059] According to the simulation results, under the same conditions, the cogging torque decreases by 2.0426 Nm when the slot openings 241 of the stator slots 24 of the adjacent stator laminations 23 are oppositely arranged compared to using pure neodymium iron boron magnetic steel. Under the same mixed magnetic steel arrangement conditions, the cogging torque decreases by 0.244, i.e. 14.64%, when the slot openings 241 of the stator slots 24 of the adjacent stator laminations 23 are misaligned compared to the slot openings 241 of the stator slots 24 of the adjacent stator laminations 23 being oppositely arranged. Under the same neodymium iron boron magnetic steel arrangement conditions, the cogging torque decreases by 0.7716, i.e. 22.26%, when the slot openings 241 of the stator slots 24 of the adjacent stator laminations 23 are misaligned compared to the slot openings 241 of the stator slots 24 of the adjacent stator laminations 23 being oppositely arranged. Therefore, compared with the prior art, the embodiment according to the present application has a significant effect in reducing cogging torque and torque fluctuation.

[0060] As shown in Figures 1-3 The motor 100 includes a rotor assembly 10 and a stator assembly 20. The rotor core 11 is composed of a plurality of silicon steel sheets stacked in the axial direction. The rotor core 11 is configured as a ring structure. The rotor core 11 is provided with a plurality of mounting groove groups. The plurality of mounting groove groups are uniformly and spacedly arranged along the circumferential direction of the rotor core 11. Each mounting groove group is provided with a plurality of mounting grooves. Each mounting groove is provided with a permanent magnet 12. The plurality of permanent magnets 12 include at least two types of permanent magnets 12 made of different materials. For example, some of the permanent magnets 12 are made of ferrite magnetic steel, and some of the permanent magnets 12 are made of rare earth magnetic steel. In this way, the demagnetization risk of the rare earth magnetic steel can be reduced, and the cost can be reduced.

[0061] It should be noted that the permanent magnets 12 made of the same material refer to the permanent magnets 12 containing the same components. In addition, the permanent magnets 12 made of different materials include the following cases:

[0062] 1. The permanent magnets 12 are different models, such as ferrite magnetic steel and neodymium iron boron magnetic steel, which are different models and different materials. For example, samarium-cobalt magnets and neodymium iron boron magnets in rare earth materials are also different models and different materials, i.e. different models and different materials of the permanent magnets 12.

[0063] 2. Permanent magnets 12 are the same model, but different grades indicate different materials. For example, they are all aluminum-cobalt-nickel (ACO) magnets, but the performance varies depending on the proportions of aluminum, cobalt, and nickel in the same volume. Therefore, grades are added to ACO magnets to identify their performance, such as remanence. For example, LNG13 and LNG32, where L represents aluminum, N represents nickel, and G represents cobalt. LNG13 has a remanence of 0.68, while LNG32 has a remanence of 1.2. Therefore, LNG32 has better remanence than LNG13, but LNG32 is more expensive.

[0064] The above description is just an example of different materials. As long as the two permanent magnets 12 contain different components, they can be considered as permanent magnets 12 of different materials in this application.

[0065] The stator assembly 20 is ring-shaped and is fitted around the outside of the rotor assembly 10. The stator assembly 20 includes a stator core 21, which is formed by stacking multiple stator laminations 23 axially. Each stator lamination 23 has multiple stator slots 24, which are constructed to pass through the stator lamination 23 along the axial direction of the stator core 21. The multiple stator slots 24 are spaced apart circumferentially along the stator laminations 23, and the multiple stator slots 24 of any two adjacent stator laminations 23 are arranged opposite each other. A coil 22 is inserted into the stator slot 24. The coil 22 is used to apply an induced magnetic field to the permanent magnet 12 when energized, so that the permanent magnet 12 can generate electromagnetic force to drive the rotor assembly 10 to move relative to the stator assembly 20.

[0066] In this configuration, the slot openings 241 of the stator slots 24 of any two adjacent stator laminations 23 can be staggered. For example, the slot openings 241 of the stator slots 24 on one stator lamination 23 can be constructed as follows: Figure 2 As shown, the slot 241 of the stator slot 24 on the adjacent stator lamination 23 is constructed as follows: Figure 3 As shown. Thus, the stator assembly 20 can be equivalently divided into two parts, one part consisting of multiple... Figure 2 The stator laminations shown are composed of 23, and another part is composed of multiple Figure 3 The stator laminations 23 shown are composed of two parts of stator laminations 23. The positions of the combined air gap magnetic flux harmonics of the two parts of stator laminations 23 can cancel each other out, so that the air gap magnetic flux waveform is a sine wave or close to a sine wave. The cogging torque generated by the two parts of stator laminations 23 is in opposite directions, which can make the cogging torque generated by the two adjacent stator laminations 23 cancel each other out, thereby reducing the overall cogging torque of the motor 100, thereby reducing the torque fluctuation of the motor 100 caused by the cogging torque, and reducing the vehicle vibration problem caused by the unstable output of the motor 100.

[0067] The motor 100 can output more stably under the same conditions, thereby reducing the motor 100 repair cost, improving the NVH performance of the motor 100, and improving the user's riding experience.

[0068] In some embodiments of the present application, referring to Figures 1-3 As shown in the figure, on the same cross section of the stator core 21, the orthographic projection of the facing stator slots 24 of any two adjacent stator laminations 23 is symmetrically arranged. Through the above arrangement, the tooth slot torque generated by the two parts of the stator laminations 23 is opposite and equal, which is conducive to improving the effect of mutual cancellation of the tooth slot torque generated by the adjacent two stator laminations 23, and further reducing the overall tooth slot torque of the motor 100.

[0069] In some embodiments of the present application, the plurality of permanent magnets 12 includes ferrite and rare earth permanent magnet pieces. For example, the permanent magnets 12 in some mounting slots can be ferrite magnetic steel, and the permanent magnets 12 in the remaining mounting slots can be rare earth permanent magnet pieces (such as neodymium iron boron magnetic steel). In this way, the amount of rare earth magnetic steel can be reduced, and the cost is reduced.

[0070] In some embodiments of the present application, on the same cross section of the rotor core 11, the permanent magnet 12 in the mounting slot with the largest area is ferrite. Through the above arrangement, the volume of the ferrite magnetic steel is large, so that the ferrite magnetic steel is not easy to demagnetize, and the ferrite magnetic steel can be used to protect the rare earth magnetic steel, reduce the demagnetization risk of the rare earth magnetic steel, improve the reliability of the rotor assembly 10, and facilitate cost reduction.

[0071] In some embodiments of the present application, at least one part of the mounting slots is provided with a segmented permanent magnet 12. For example, referring to Figures 4-5 As shown in the figure, the permanent magnets 12 in some mounting slots can be segmented; or, the permanent magnets 12 in all mounting slots can be segmented, which is not limited in the present application.

[0072] It should be noted that according to the principle of superposition method, the total tooth slot torque of each pole of the motor 100 can be simplified as the superposition of the tooth slot torque generated by each segment of the permanent magnet 12, which satisfies:

[0073]

[0074] In the formula: Ns is the number of segments of the permanent magnet 12; Tn is the tooth slot torque amplitude of the n-th harmonic; Np is the number of tooth slot torque periods of one pitch; Z is the number of slots; Δβ is the offset angle of the adjacent two segments of the permanent magnet 12. The number of tooth slot torque periods of one pitch: Np = 2p / GCD(Z, 2p), wherein: GCD(Z, 2p) represents the greatest common divisor of Z and 2p. As can be seen from the above formula, by changing the number of segments Ns of the permanent magnet 12, the total tooth slot torque of each pole can be effectively weakened.

[0075] Therefore, by segmenting the permanent magnet 12 in the mounting slot, the cogging torque can be reduced, thereby reducing the torque fluctuation caused by the cogging torque. This reduces the vibration problem caused by unstable output due to torque fluctuation, which is beneficial to improving NVH performance.

[0076] In some embodiments of the present invention, the permanent magnets 12 arranged in segments within the same mounting slot have different lengths. For example, refer to... Figures 4-5 As shown, the permanent magnet 12 in the mounting slot can be divided into two segments, with the two segments having different lengths; or, the permanent magnet 12 in the mounting slot can be divided into multiple segments, with at least one of the multiple segments having a different length from the others. This application does not impose any limitations on this. Thus, non-uniform segmentation of the permanent magnet 12 can be achieved. Compared to uniform segmentation, non-uniform segmentation is more effective in reducing cogging torque.

[0077] In some embodiments of the present invention, on the same cross section of the stator core 21, the width of the slot 241 of the stator slot 24 is W, and the stator core 21 satisfies the following relationship: 0.13mm≤W≤5.07mm.

[0078] For example, refer to Figure 2 As shown, on the same cross-section of the stator core 21, the width of the slot opening 241 of the stator slot 24 can be set to W, satisfying the following relationship: 0.13mm ≤ W ≤ 5.07mm. That is, the width W of the slot opening 241 of the stator slot 24 can be 0.5mm; or, the width W of the slot opening 241 of the stator slot 24 can be 2.5mm; or, the width W of the slot opening 241 of the stator slot 24 can be 5.5mm, and this application does not impose any restrictions on this. Through the above settings, the overall cogging torque of the motor 100 can be reduced, torque fluctuation can be reduced, NVH performance can be improved, and the processing cost of the slot opening 241 of the stator slot 24 can be reduced, which is beneficial to improving the practicality of the motor 100.

[0079] In a more preferred embodiment, the stator core 21 satisfies the following relationship: 0.63mm≤W≤5mm, which has a more significant effect than the above.

[0080] In some embodiments of the present invention, on the same cross section of the stator core 21, the line connecting the center of the slot opening 241 of the stator slot 24 in the width direction with the center of the stator core 21 is the first line, and the line connecting the center of the stator slot 24 in the width direction with the center of the stator core 21 is the second line. The included angle between the first line and the second line is α, and the stator core 21 satisfies the following relationship: 0.1°≤α≤5°.

[0081] For example, refer to Figure 2 As shown, on the same cross-section of the stator core 21, the center of the slot opening 241 of the stator slot 24 in the width direction can be connected to the center of the stator core 21, and this connection line can be designated as the first connection line. The center of the same stator slot 24 in the width direction can be connected to the center of the stator core 21, and this connection line can be designated as the second connection line. An angle is formed between the first and second connection lines, and the value of the angle between the first and second connection lines is α. The stator core 21 satisfies the following relationship: 0.1° ≤ α ≤ 5°. That is, the angle α between the first and second connection lines can be 0.5°; or, the angle α between the first and second connection lines can be 2.5°; or, the angle α between the first and second connection lines can be 4.5°. This application does not impose any restrictions on this.

[0082] The above settings can reduce the overall cogging torque of the motor 100, reduce torque fluctuation, improve NVH performance, and reduce the processing cost of the slot 241 of the stator slot 24, thereby improving the practicality of the motor 100.

[0083] In a more preferred embodiment, the stator core 21 satisfies the following relationship: 1°≤α≤3°, which has a more significant effect than the above.

[0084] In some embodiments of the present invention, on the same cross-section of the stator core 21, the width of the slot opening 241 of the stator slot 24 is W, the line connecting the center of the slot opening 241 in the width direction to the center of the stator core 21 is a first line, the line connecting the center of the slot 24 in the width direction to the center of the stator core 21 is a second line, the angle between the first line and the second line is α, and the stator core 21 satisfies the following relationship:

[0085] For example, refer to Figure 2 As shown, on the same cross-section of the stator core 21, the width of the slot opening 241 of the stator slot 24 can be set as W. The center of the slot opening 241 in the width direction can be connected to the center of the stator core 21, and this connection line can be set as the first connection line. The center of the same stator slot 24 in the width direction can be connected to the center of the stator core 21, and this connection line can be set as the second connection line. An angle is formed between the first connection line and the second connection line, and the value of the angle between the first connection line and the second connection line is set as α. The stator core 21 satisfies the following relationship:

[0086] That is, the ratio of the value W of the width of the slot opening 241 of the stator slot 24 to the value a of the included angle between the first line and the second line can be 0.9, or the ratio of the value W of the width of the slot opening 241 of the stator slot 24 to the value a of the included angle between the first line and the second line can be 1.15, or the ratio of the value W of the width of the slot opening 241 of the stator slot 24 to the value a of the included angle between the first line and the second line can be 1.4, and the present application does not limit this. Through the above setting, the overall cogging torque of the motor 100 can be small, the torque fluctuation is small, the NVH performance is high, and the machining process cost of the slot opening 241 of the stator slot 24 can be low, which is beneficial to improve the practicability of the motor 100.

[0087] In a more preferred embodiment, the stator core 21 satisfies the following relationship: The effect is more obvious than the above.

[0088] In some embodiments of the application, the plurality of mounting grooves include first mounting grooves 111, second mounting grooves 112 and third mounting grooves 113, the first mounting grooves 111 are located radially outward of the third mounting grooves 113, the second mounting grooves 112 extend along the radial direction of the rotor core 11, and one first mounting groove 111 and one third mounting groove 113 are provided between adjacent two second mounting grooves 112; the corresponding permanent magnets 12 of the first mounting grooves 111 include the first permanent magnets 121 and the second permanent magnets 122 arranged in sections, the corresponding permanent magnets 12 of the second mounting grooves 112 include the third permanent magnets 123 and the fourth permanent magnets 124 arranged in sections, and the corresponding permanent magnets 12 of the third mounting grooves 113 include the fifth permanent magnets 125 and the sixth permanent magnets 126 arranged in sections.

[0089] For example, as shown in FIG. 1, Figures 4-7 The mounting groove group includes the first mounting grooves 111, a plurality of first mounting grooves 111 can be arranged uniformly spaced apart in the circumferential direction of the rotor core 11, the first mounting grooves 111 are located radially outward of the rotor core 11, and the first mounting grooves 111 extend linearly in the direction perpendicular to the d-axis of the rotor core 11 (or as shown in FIG. 1, Figure 8The first permanent magnet 121 and the second permanent magnet 122 are arranged in sequence along the length direction of the first mounting slot 111, the width dimension of the first permanent magnet 121 is equal to the width dimension of the second permanent magnet 122, so that the end of the first permanent magnet 121 along the length direction can be opposite to the end of the second permanent magnet 122 along the length direction, and the first permanent magnet 121 and the second permanent magnet 122 can be connected by means of gluing or welding. Meanwhile, the length dimension of the first permanent magnet 121 is different from the length dimension of the second permanent magnet 122, and the length ratio between the first permanent magnet 121 and the second permanent magnet 122 can be generally set to be between 1:2 and 1:7. For example, the length dimension of the second permanent magnet 122 can be set to be twice the length dimension of the first permanent magnet 121, which is not limited in the present application.

[0090] Meanwhile, the mounting slot group further comprises the second mounting slot 112, the second mounting slot 112 extends along the radial direction of the rotor core 11, and each mounting slot group is provided with two second mounting slots 112, the two second mounting slots 112 are respectively located on the two sides of the first mounting slot 111 in the circumferential direction and are symmetrical about the d-axis. The permanent magnet 12 mounted in the second mounting slot 112 comprises a third permanent magnet 123 and a fourth permanent magnet 124, the third permanent magnet 123 and the fourth permanent magnet 124 are arranged in sequence along the length direction of the second mounting slot 112, the width dimension of the third permanent magnet 123 is equal to the width dimension of the fourth permanent magnet 124, so that the end of the third permanent magnet 123 along the length direction can be opposite to the end of the fourth permanent magnet 124 along the length direction, and the third permanent magnet 123 and the fourth permanent magnet 124 can be connected by means of gluing or welding. Meanwhile, the length dimension of the third permanent magnet 123 is different from the length dimension of the fourth permanent magnet 124, and the length ratio between the third permanent magnet 123 and the fourth permanent magnet 124 can be generally set to be between 1:2 and 1:7. For example, the length dimension of the fourth permanent magnet 124 can be set to be twice the length dimension of the third permanent magnet 123, which is not limited in the present application.

[0091] Meanwhile, the mounting groove set further comprises third mounting grooves 113, a plurality of third mounting grooves 113 can be arranged at uniform intervals along the circumferential direction of the rotor core 11, the third mounting grooves 113 are located at the radially inner side of the first mounting grooves 111, the third mounting grooves 113 are arranged along the direction perpendicular to the d-axis of the rotor core 11 and are symmetrically arranged about the d-axis, and the circumferential two sides of each third mounting groove 113 are respectively provided with a second mounting groove 112. The permanent magnet 12 mounted in the third mounting groove 113 comprises a fifth permanent magnet 125 and a sixth permanent magnet 126, the fifth permanent magnet 125 and the sixth permanent magnet 126 are arranged in sections, the fifth permanent magnet 125 and the sixth permanent magnet 126 are arranged in sequence along the length direction of the second mounting groove 112, the width dimension of the fifth permanent magnet 125 and the width dimension of the sixth permanent magnet 126 are equal, so that the end of the fifth permanent magnet 125 along the length direction can be opposite to the end of the sixth permanent magnet 126 along the length direction, and the fifth permanent magnet 125 and the sixth permanent magnet 126 can be connected by means of gluing or welding. Meanwhile, the length dimension of the fifth permanent magnet 125 and the length dimension of the sixth permanent magnet 126 are different, and the length ratio between the fifth permanent magnet 125 and the sixth permanent magnet 126 can be generally set to be between 1:2 and 1:7. For example, the length dimension of the sixth permanent magnet 126 can be set to be twice the length dimension of the fifth permanent magnet 125, and the present application does not make any limitation in this regard.

[0092] Through the above arrangement, the permanent magnet 2 can be divided into multiple layers, which is beneficial to improve the demagnetization resistance of the permanent magnet 2, improves the reliability of the rotor assembly 10, and realizes the uneven segmentation of the permanent magnet 12, which can effectively reduce the cogging torque, thereby reducing the torque fluctuation caused by the cogging torque and reducing the shaking problem caused by the unstable output of the torque fluctuation.

[0093] In some embodiments of the present application, in the radial direction of the rotor core 11, the width of the first permanent magnet 121 and the second permanent magnet 122 is in the range of 2mm-7mm, and the width of the fifth permanent magnet 125 and the sixth permanent magnet 126 is in the range of 5mm-12mm; in the circumferential direction of the rotor core 11, the third permanent magnet 123 and the fourth permanent magnet 124 are in the range of 2mm-7mm.

[0094] For example, with reference to Figure 1As shown, the width of the first permanent magnet 121 and the second permanent magnet 122 can be set to 3mm; or the width of the first permanent magnet 121 and the second permanent magnet 122 can be set to 4.5mm; or the width of the first permanent magnet 121 and the second permanent magnet 122 can be set to 6mm; or the width of the first permanent magnet 121 and the second permanent magnet 122 can be set to any value meeting the condition, which is not limited in the application. Similarly, the third permanent magnet 123 and the fourth permanent magnet 124 are the same as above, which is not repeated here. Thus, the requirement of high magnetic density of the high-speed motor 100 is realized, the weight of the first permanent magnet 121 and the second permanent magnet 122 is reduced, the centrifugal force of the rotor assembly 10 in the rotating process is reduced, and the stability of the rotor assembly 10 is improved.

[0095] In addition, the width of the fifth permanent magnet 125 and the sixth permanent magnet 126 can be set to 6mm; or the width of the fifth permanent magnet 125 and the sixth permanent magnet 126 can be set to 8.5mm; or the width of the fifth permanent magnet 125 and the sixth permanent magnet 126 can be set to 11mm; or the width of the fifth permanent magnet 125 and the sixth permanent magnet 126 can be set to any value meeting the condition, which is not limited in the application. Thus, when the motor 100 runs at high speed, if the permanent magnet 12 is insufficiently cooled within a certain temperature range, the demagnetization of the permanent magnet 12 can be ensured, and the reliability of the rotor assembly 10 is improved.

[0096] In some embodiments of the application, on the same cross section of the rotor core 11, the minimum distance between the first mounting groove 111 and the outer peripheral wall of the rotor core 11 is L1, the minimum distance between the second mounting groove 112 and the outer peripheral wall of the rotor core 11 is L2, the minimum distance between the third mounting groove 113 and the outer peripheral wall of the rotor core 11 is L3, and the rotor core 11 satisfies the following relationship:

[0097] For example, with reference to Figures 5-7As shown, on the same cross section of the rotor core 11, a first mounting groove 111 can be arranged to extend along the circumferential direction of the rotor core 11, the outermost edge of the first mounting groove 111 is arranged to be spaced apart from the outer circumferential wall of the rotor core 11, and the radial distance between the outermost edge of the first mounting groove 111 and the outer circumferential wall of the rotor core 11 is set as L1; a second mounting groove 112 can be arranged to extend along the radial direction of the rotor core 11, the outermost edge of the second mounting groove 112 is arranged to be spaced apart from the outer circumferential wall of the rotor core 11, and the radial distance between the outermost edge of the second mounting groove 112 and the outer circumferential wall of the rotor core 11 is set as L2; a third mounting groove 113 can be arranged to be mounted on the inner side of the first mounting groove 111, and the third mounting groove 113 is arranged to extend along the circumferential direction of the rotor core 11, the outermost edge of the third mounting groove 113 is arranged to be spaced apart from the outer circumferential wall of the rotor core 11, and the radial distance between the outermost edge of the third mounting groove 113 and the outer circumferential wall of the rotor core 11 is set as L3.

[0098] Wherein, L1, L2 and L3 satisfy the following relationship: That is, the ratio of the radial distance L3 between the outermost edge of the third mounting groove 113 and the outer circumferential wall of the rotor core 11 and the radial distance L1 between the outermost edge of the first mounting groove 111 and the outer circumferential wall of the rotor core 11 is greater than or equal to 2.5 times the ratio of the radial distance L2 between the outermost edge of the second mounting groove 112 and the outer circumferential wall of the rotor core 11 and the radial distance L1 between the outermost edge of the first mounting groove 111 and the outer circumferential wall of the rotor core 11, and is less than or equal to 3.1 times the ratio of the radial distance L3 between the outermost edge of the third mounting groove 113 and the outer circumferential wall of the rotor core 11 and the radial distance L2 between the outermost edge of the second mounting groove 112 and the outer circumferential wall of the rotor core 11.

[0099] Because the position of the mounting slot determines the position of the permanent magnet 12, when the distance between the mounting slot and the outer surface of the rotor core 11 changes, the distance between the permanent magnet 12 and the outer surface of the rotor core 11 also changes. This change in distance between the permanent magnet 12 and the outer surface of the rotor core 11 causes a change in the pole arc coefficient, which is determined by the ratio of the average magnetic flux density in the air gap to the maximum magnetic flux density in the air gap. In other words, the pole arc coefficient is affected by the arc length of the outer surface of the rotor core 11 corresponding to the permanent magnet 12 and the length of the magnetic bridge of the magnet. Changing the outermost distance of the permanent magnet 12 from the rotor core 11 will change the arc length of the outer surface of the permanent magnet 12 relative to the rotor core 11 or the air gap magnetic flux density. During movement, there is an optimal range for the pole arc coefficient, within which the air gap magnetic flux density waveform is closest to a sine wave. Therefore, limiting the relationship between the distances L1, L2, and L3 within the aforementioned range ensures that the air gap magnetic flux density waveform is closest to a sine wave, resulting in a smaller range for cogging torque and torque fluctuation. This reduces torque ripple and cogging torque, thus improving NVH performance.

[0100] In a more preferred embodiment, the rotor core 11 satisfies the following relationship: Its effect is more obvious than the above.

[0101] In some embodiments of the present invention, on the same cross-section of the rotor core 11, the line connecting the geometric center of the first permanent magnet 121 and the center of the rotor core 11 is the third line, with a length of L4; the line connecting the geometric center of the second permanent magnet 122 and the center of the rotor core 11 is the fourth line, with a length of L5; and the line connecting the geometric center of the third permanent magnet 123 and the center of the rotor core 11 is the fifth line, with a length of L6. The rotor core 11 satisfies the following relationship:

[0102] For example, refer to Figures 5-7 As shown, on the same cross-section of the rotor core 11, the geometric center of the first permanent magnet 121 can be connected to the center of the rotor core 11 through a third line, and the length of the third line is set to L4; the geometric center of the second permanent magnet 122 can be connected to the center of the rotor core 11 through a fourth line, and the length of the fourth line is set to L5; the geometric center of the third permanent magnet 123 can be connected to the center of the rotor core 11 through a fifth line, and the length of the fifth line is set to L6.

[0103] Among them, L4, L5, and L6 satisfy the following relationship: In other words, the length L4 of the third connection can be set to be less than or equal to 1.1 times the length L5 of the fourth connection, and the length L5 of the fourth connection can be set to be greater than or equal to 1.01 times the length L6 of the fifth connection. Therefore, changing the distance between the magnet and the outermost edge of the rotor will change the arc length of the rotor's outer surface relative to the magnet or the air gap magnetic flux density. During movement, there is an optimal range for the pole arc coefficient. Within this range, the air gap magnetic flux density waveform is closest to a sine wave, the cogging torque has a smaller range, and the torque fluctuation also has a smaller range. This makes the layout of the permanent magnet 12 more reasonable and helps improve the demagnetization resistance of the rotor assembly 10.

[0104] In a more preferred embodiment, the rotor core 11 satisfies the following relationship: Its effect is more obvious than the above.

[0105] In some embodiments of the present invention, on the same cross-section of the stator core 21, the width of the slot opening 241 of the stator slot 24 is W, the line connecting the center of the slot opening 241 in the width direction of the stator slot 24 and the center of the stator core 21 is the first line, the line connecting the center of the width of the stator slot 24 and the center of the stator core 21 is the second line, and the angle between the first line and the second line is α; on the same cross-section of the rotor core 11, the line connecting the geometric center of the first permanent magnet 121 and the center of the rotor core 11 is the third line, the length of the third line is L4, the angle between the third line and the d-axis is α1, the line connecting the geometric center of the second permanent magnet 122 and the center of the rotor core 11 is the fourth line, the length of the fourth line is L5, the angle between the fourth line and the d-axis is α2, the width of the first permanent magnet 121 is W1, the width of the fifth permanent magnet 125 is W5, and the rotor core 11 satisfies the following relationship:

[0106]

[0107] For example, refer to Figure 2 As shown, on the same cross-section of the stator core 21, the width of the slot opening 241 of the stator slot 24 can be set as W. The center of the slot opening 241 in the width direction of the stator slot 24 can be connected to the center of the stator core 21 and the connection line can be set as the first connection line. The center of the same stator slot 24 in the width direction can be connected to the center of the stator core 21 and the connection line can be set as the second connection line. An angle is formed between the first connection line and the second connection line, and the value of the angle between the first connection line and the second connection line is set as α.

[0108] At the same time, refer to Figures 5-7As shown, on the same cross section of the rotor core 11, the geometric center of the first permanent magnet 121 and the center of the rotor core 11 can be connected to form a third connecting line, the length of the third connecting line is L4, and the angle between the third connecting line and the d-axis is a1; the geometric center of the second permanent magnet 122 and the center of the rotor core 11 can be connected to form a fourth connecting line, the length of the fourth connecting line is L5, and the angle between the fourth connecting line and the d-axis is a2; the width of the first permanent magnet 121 is W1, and the width of the fifth permanent magnet 125 is W5.

[0109] Wherein, the rotor core 11 satisfies the following relationship: That is, the ratio of the width W of the slot opening 241 of the stator slot 24 to the angle a between the first connecting line and the second connecting line multiplied by the ratio of the width W5 of the fifth permanent magnet 125 to the width W1 of the first permanent magnet 121 is greater than or equal to 0.059 times the product of the length L4 of the third connecting line and , and less than or equal to 0.19 times the product of the length L5 of the fourth connecting line and .

[0110] Through the above setting, the cogging torque of the motor 100 as a whole can be reduced, thereby reducing the torque fluctuation of the motor 100 caused by the cogging torque, reducing the whole vehicle shaking problem caused by the unstable output of the motor 100, and improving the NVH performance of the vehicle.

[0111] In a more preferred embodiment, the rotor core 11 satisfies the following relationship: The effect is more obvious than the above.

[0112] In some embodiments of the present application, on the same cross section of the stator core 21, the width of the slot opening 241 of the stator slot 24 is W, the connecting line between the width center of the slot opening 241 of the stator slot 24 and the center of the stator core 21 is the first connecting line, the connecting line between the width center of the stator slot 24 and the center of the stator core 21 is the second connecting line, and the angle between the first connecting line and the second connecting line is a; on the same cross section of the rotor core 11, the connecting line between the geometric center of the third permanent magnet 123 and the center of the rotor core 11 is the fifth connecting line, the length of the fifth connecting line is L6, the angle between the fifth connecting line and the d-axis is a3, the connecting line between the geometric center of the fourth permanent magnet 124 and the center of the rotor core 11 is the sixth connecting line, the length of the sixth connecting line is L7, the angle between the sixth connecting line and the d-axis is a4, the width of the second permanent magnet 122 is W2, the width of the sixth permanent magnet 126 is W6, and the rotor core 11 satisfies the following relationship:

[0113]

[0114] For example, refer to Figure 2 As shown, on the same cross-section of the stator core 21, the width of the slot opening 241 of the stator slot 24 can be set as W. The center of the slot opening 241 in the width direction of the stator slot 24 can be connected to the center of the stator core 21 and the connection line can be set as the first connection line. The center of the same stator slot 24 in the width direction can be connected to the center of the stator core 21 and the connection line can be set as the second connection line. An angle is formed between the first connection line and the second connection line, and the value of the angle between the first connection line and the second connection line is set as α.

[0115] At the same time, refer to Figures 5-7 As shown, on the same cross-section of the rotor core 11, the geometric center of the third permanent magnet 123 can be connected to the center of the rotor core 11 and this connection line is designated as the fifth connection line. The length of the fifth connection line is designated as L6, and the angle between the fifth connection line and the d-axis is designated as α3. The geometric center of the fourth permanent magnet 124 can be connected to the center of the rotor core 11 and this connection line is designated as the sixth connection line. The length of the sixth connection line is designated as L7, and the angle between the sixth connection line and the d-axis is designated as α4. The width of the second permanent magnet 122 is designated as W2, and the width of the sixth permanent magnet 126 is designated as W6.

[0116] The rotor core 11 satisfies the following relationship: In other words, the product of the ratio of the width W of the slot 241 of the stator slot 24 to the angle α between the first and second connecting lines, multiplied by the ratio of the width W6 of the sixth permanent magnet 126 to the width W2 of the second permanent magnet 122, is greater than or equal to the length L7 of the sixth connecting line multiplied by the length L7 of the second permanent magnet 122. The product of 0.077 times, and less than or equal to the length L6 of the fifth connection. 0.21 times the product of .

[0117] By setting the above, the overall cogging torque of motor 100 can be reduced, thereby reducing the torque fluctuation of motor 100 caused by cogging torque, reducing the vehicle vibration problem caused by unstable output of motor 100, and improving the vehicle's NVH performance.

[0118] In a more preferred embodiment, the rotor core 11 satisfies the following relationship: Its effect is more obvious than the above.

[0119] In some embodiments of the present invention, on the same cross-section of the stator core 21, the width of the slot opening 241 of the stator slot 24 is W, the line connecting the center of the slot opening 241 in the width direction of the stator slot 24 and the center of the stator core 21 is the first line, the line connecting the center of the width of the stator slot 24 and the center of the stator core 21 is the second line, and the angle between the first line and the second line is α; on the same cross-section of the rotor core 11, the line connecting the geometric center of the fifth permanent magnet 125 and the center of the rotor core 11 is the seventh line, the length of the seventh line is L8, the angle between the seventh line and the d-axis is α5, the line connecting the geometric center of the sixth permanent magnet 126 and the center of the rotor core 11 is the eighth line, the length of the eighth line is L9, the angle between the eighth line and the d-axis is α6, the width of the third permanent magnet 123 is W3, the width of the sixth permanent magnet 126 is W6, and the rotor core 11 satisfies the following relationship:

[0120]

[0121] For example, refer to Figure 2 As shown, on the same cross-section of the stator core 21, the width of the slot opening 241 of the stator slot 24 can be set as W. The center of the slot opening 241 in the width direction of the stator slot 24 can be connected to the center of the stator core 21 and the connection line can be set as the first connection line. The center of the same stator slot 24 in the width direction can be connected to the center of the stator core 21 and the connection line can be set as the second connection line. An angle is formed between the first connection line and the second connection line, and the value of the angle between the first connection line and the second connection line is set as α.

[0122] At the same time, refer to Figures 5-7 As shown, on the same cross-section of the rotor core 11, the geometric center of the fifth permanent magnet 125 can be connected to the center of the rotor core 11 and this connection line is designated as the seventh connection line. The length of the seventh connection line is designated as L8, and the angle between the seventh connection line and the d-axis is designated as α5. The geometric center of the sixth permanent magnet 126 can be connected to the center of the rotor core 11 and this connection line is designated as the eighth connection line. The length of the eighth connection line is designated as L9, and the angle between the eighth connection line and the d-axis is designated as α6. The width of the third permanent magnet 123 is designated as W3, and the width of the sixth permanent magnet 126 is designated as W6.

[0123] The rotor core 11 satisfies the following relationship: In other words, the product of the ratio of the width W of the slot 241 of the stator slot 24 to the angle α between the first and second connecting lines, multiplied by the ratio of the width W6 of the sixth permanent magnet 126 to the width W3 of the third permanent magnet 123, is greater than or equal to the length L8 of the seventh connecting line. The product of 0.083 times, and less than or equal to the length L9 of the eighth connecting line. 0.28 times of the product of the first permanent magnet 121 and the second permanent magnet 122.

[0124] Through the above setting, the cogging torque of the motor 100 as a whole can be reduced, thereby reducing the torque fluctuation of the motor 100 caused by the cogging torque, reducing the problem of vehicle jitter caused by the uneven output of the motor 100, and improving the NVH performance of the vehicle.

[0125] In a more preferred embodiment, the rotor core 11 satisfies the following relationship: The effect is more obvious than the above.

[0126] It should be noted that when the stator core 21 is provided with the stator slot 24 and the stator slot 24 is provided with the slot opening 241, and when the rotor core 11 is provided with the first mounting slot 111, the second mounting slot 112 and the third mounting slot 113, and the first permanent magnet 121 and the second permanent magnet 122 are arranged in the first mounting slot 111, the third permanent magnet 123 and the fourth permanent magnet 124 are arranged in the second mounting slot 112, and the fifth permanent magnet 125 and the sixth permanent magnet 126 are arranged in the third mounting slot 113, if the following conditions are met at the same time:

[0127] (1), 0.13mm≤W≤5.07mm;

[0128] (2), 0.1°≤α≤5°;

[0129] (3), 0.63≤ ≤1.67;

[0130] (4),

[0131] (5),

[0132] (6),

[0133] (7),

[0134] (8),

[0135] then from the comprehensive consideration of reducing torque fluctuation and improving NVH performance, the overall performance of the motor 100 is the best.

[0136] Specifically, referring to Figures 5-7As shown, when L1, L2, L3, L4, L5, L6, L7, L8, L9 are reduced, i.e. the permanent magnet 12 is moved inwardly of the rotor core 11, the air gap flux density is reduced, the performance of the permanent magnet 12 cannot be fully utilized, the output torque is reduced, the output power of the motor 100 is reduced, and the efficiency of the motor 100 is reduced; when L1, L2, L3, L4, L5, L6, L7, L8, L9 are increased, i.e. the permanent magnet 12 is moved outwardly of the rotor core 11, if the motor 100 is operated at high speed, the possibility of occurrence of the bore sweeping phenomenon is increased. When L1, L2, L3, L4, L5, L6, L7, L8, L9 are increased, the magnetic flux leakage is increased, and the utilization rate of the permanent magnet 12 is reduced; when L1, L2, L3, L4, L5, L6, L7, L8, L9 are reduced, the mechanical strength of the rotor core 11 is reduced, the stress concentration phenomenon is likely to occur, the limit speed of the motor 100 is reduced, and the motor 100 weak magnetic field is affected.

[0137] When α1, α2, α3, α4, α5, α6 are changed, i.e. the air gap magnetic field of the motor 100 is changed, the load torque and the NVH performance are affected. When the above angles are changed from small to large, the arc length crossed by the permanent magnet 12 is changed, the air gap flux density of the motor 100 is affected, the air gap flux density fluctuates, the output power of the motor 100 fluctuates, and the NVH performance of the motor 100 fluctuates. The above angles have an optimal coefficient range, as shown in the above parameter expression. When the above parameters are within the range, the load torque and the NVH performance of the motor 100 are best.

[0138] When W1, W2, W3, W4, W5, W6 are increased, the cost of the permanent magnet 12 is increased, and the operation of the permanent magnet 12 is affected, but the anti-demagnetization ability of the motor 100 is enhanced. When W1, W2, W3, W4, W5, W6 are reduced, i.e. the anti-demagnetization ability of the permanent magnet 12 is reduced, the output torque of the motor 100 is affected.

[0139] When L1, L2, L3, L4, L5, L6, L7, L8, L9 are changed, α1, α2, α3, α4, α5, α6 are changed, at this time, the limit speed, the mechanical strength, and the anti-leakage ability of the motor 100 have a fluctuation range. When the above parameter relationship is satisfied, the limit speed, the mechanical strength, and the anti-leakage ability of the motor 100 can theoretically reach the maximum value allowed by the rotor. When W1, W2, W3, W4, W5, W6 are changed, the cost, the anti-demagnetization ability, the load torque, and the NVH performance of the permanent magnet 12 fluctuate; α1, α2, α3, α4, α5, α6 change with the width of the permanent magnet 12, affect the pole arc coefficient of the motor 100, and thus affect the load torque and the NVH performance of the motor 100. The pole arc coefficient has an optimal range, when the above parameter relationship is satisfied, the pole arc coefficient is within the optimal range, and the load torque and the NVH performance of the motor 100 are best.

[0140] In summary, the limits in the above parameter relationship should be satisfied, and the motor 100 has the best performance in comprehensive consideration.

[0141] The application further provides a vehicle.

[0142] The vehicle according to the embodiments of the application comprises the motor 100 according to any of the above embodiments.

[0143] According to the vehicle of the embodiments of the application, the slot openings 241 of the oppositely arranged stator slots 24 of any two adjacent stator laminations 23 of the stator assembly 20 are arranged in a staggered manner, so that the cogging torques of the at least partial teeth of the two adjacent stator laminations 23 are offset to each other, thereby reducing the cogging torque of the motor 100, reducing the torque fluctuation and the shaking caused by the torque fluctuation, improving the control accuracy of the motor 100, improving the NVH performance of the motor 100, and by arranging the plurality of permanent magnets 12 including at least two permanent magnets 12 made of different materials, the demagnetization resistance of the permanent magnets 12 is improved, the cost of the rotor assembly 10 is reduced, the cost of the motor 100 is reduced, and the practicability of the vehicle is improved.

[0144] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0145] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. An electric machine characterized in that, The application relates to a rotor assembly and a stator assembly. The rotor assembly comprises a rotor core and a plurality of permanent magnets, the rotor core is provided with a plurality of mounting slots, each of the mounting slots is provided with the permanent magnet, and the plurality of permanent magnets comprise permanent magnets made of at least two different materials. The stator assembly is arranged outside the rotor assembly, and comprises a stator core, the stator core is stacked by a plurality of stator laminations along the axial direction, each of the stator laminations is provided with a plurality of stator slots arranged along the circumferential direction, each of the stator slots has a slot opening located on the inner wall of the stator core, and the plurality of stator slots of any two adjacent stator laminations are arranged in one-to-one correspondence in the axial direction of the stator core, and the slot openings of the stator slots arranged in correspondence of any two adjacent stator laminations are arranged in a staggered mode. In the same cross section of the stator core, the width of the slot opening of the stator slot is W, the first connecting line is a line connecting the center of the width direction of the slot opening of the stator slot and the center of the stator core, the second connecting line is a line connecting the center of the width direction of the slot opening of the stator slot and the center of the stator core, the included angle of the first connecting line and the second connecting line is alpha, and the stator core satisfies the following relationship: 0.63≤ ≤1.67。 2. The electric machine of claim 1, wherein, In the same cross section of the stator core, the orthographic projections of the stator slots arranged in correspondence of any two adjacent stator laminations are arranged in a symmetrical mode.

3. The electric machine of claim 1, wherein, The plurality of permanent magnets comprise ferrite and rare earth permanent magnet pieces.

4. The electric machine of claim 3, wherein, In the same cross section of the rotor core, the permanent magnet arranged in the mounting slot with the largest area is the ferrite.

5. The electric machine of claim 1, wherein, At least a part of the mounting slots are provided with the permanent magnets arranged in a segmented mode.

6. The electric machine of claim 5, wherein, The lengths of the permanent magnets arranged in the same mounting slot in a segmented mode are different.

7. The electric machine of claim 1, wherein, In the same cross section of the stator core, the width of the slot opening of the stator slot is W, and the stator core satisfies the following relationship: 0.13mm<=W<=5.07mm.

8. The electric machine of claim 7, wherein, The stator core satisfies the following relationship: 0.63mm<=W<=5mm.

9. The electric machine of claim 1, wherein, In the same cross section of the stator core, the first connecting line is a line connecting the center of the width direction of the slot opening of the stator slot and the center of the stator core, the second connecting line is a line connecting the center of the width direction of the slot opening of the stator slot and the center of the stator core, the included angle of the first connecting line and the second connecting line is alpha, and the stator core satisfies the following relationship: 0.1°≤α≤5°。 10. The electric machine of claim 9, wherein, The stator core satisfies the following relationship: 1°≤α≤3°。 11. The electric machine of claim 1, wherein, The stator core satisfies the following relationship: 1.07≤ ≤1.3。 12. The electric machine of any one of claims 1-11, wherein, The plurality of mounting slots include a first mounting slot, a second mounting slot, and a third mounting slot, the first mounting slot is located radially outward of the third mounting slot, the second mounting slot extends along the radial direction of the rotor core, and one first mounting slot and one third mounting slot are arranged between two adjacent second mounting slots; the corresponding permanent magnets arranged in the first mounting slot include a first permanent magnet and a second permanent magnet arranged in segments, the corresponding permanent magnets arranged in the second mounting slot include a third permanent magnet and a fourth permanent magnet arranged in segments, and the corresponding permanent magnets arranged in the third mounting slot include a fifth permanent magnet and a sixth permanent magnet arranged in segments.

13. The electric machine of claim 12, wherein, In the circumferential direction of the rotor core, the ratio of the length of the first permanent magnet to the length of the second permanent magnet is greater than or equal to 1 / 7 and less than or equal to 1 / 2, and the ratio of the length of the fifth permanent magnet to the length of the sixth permanent magnet is greater than or equal to 1 / 7 and less than or equal to 1 / 2; in the radial direction of the rotor core, the ratio of the length of the third permanent magnet to the length of the fourth permanent magnet is greater than or equal to 1 / 7 and less than or equal to 1 / 2.

14. The electric machine of claim 12, wherein, In the radial direction of the rotor core, the width of the first permanent magnet and the second permanent magnet is in the range of 2mm-7mm, and the width of the fifth permanent magnet and the sixth permanent magnet is in the range of 5mm-12mm; in the circumferential direction of the rotor core, the width of the third permanent magnet and the fourth permanent magnet is in the range of 2mm-7mm.

15. The electric machine of claim 12, wherein, On the same cross section of the rotor core, the minimum distance between the first mounting slot and the outer peripheral wall of the rotor core is L1, the minimum distance between the second mounting slot and the outer peripheral wall of the rotor core is L2, and the minimum distance between the third mounting slot and the outer peripheral wall of the rotor core is L3, and the rotor core satisfies the following relationship: 2.5* ≤ ≤3.1* 。 16. The electric machine of claim 15, wherein, The rotor core satisfies the following relationship: 1.52* ≤ ≤1.07* 。 17. The electric machine of claim 12, wherein, On the same cross section of the rotor core, the connecting line between the geometric center of the first permanent magnet and the center of the rotor core is a third connecting line, the length of the third connecting line is L4, the connecting line between the geometric center of the second permanent magnet and the center of the rotor core is a fourth connecting line, the length of the fourth connecting line is L5, the connecting line between the geometric center of the third permanent magnet and the center of the rotor core is a fifth connecting line, the length of the fifth connecting line is L6, and the rotor core satisfies the following relationship: 1.01* ≤ ≤1.1* 。 18. The electric machine of claim 17, wherein, The rotor core satisfies the following relationship: 1.04* ≤ ≤0.9* 。 19. The electric machine of claim 12, wherein, On the same cross section of the stator core, the width of the slot opening of the stator slot is W, the center line between the width center of the slot opening of the stator slot and the center of the stator core is the second connecting line, and the included angle between the first connecting line and the second connecting line is α; on the same cross section of the rotor core, the center line between the geometric center of the first permanent magnet and the center of the rotor core is the third connecting line, the length of the third connecting line is L4, the included angle between the third connecting line and the d-axis is α1, the center line between the geometric center of the second permanent magnet and the center of the rotor core is the fourth connecting line, the length of the fourth connecting line is L5, the included angle between the fourth connecting line and the d-axis is α2, the width of the first permanent magnet is W1, the width of the fifth permanent magnet is W5, and the rotor core satisfies the following relationship: 0.059*L4 ≤ ≤0.19*L5 .

20. The electric machine of claim 19, wherein, The rotor core satisfies the following relationship: 0.084*L4 ≤ ≤0.11*L5 .

21. The electric machine of claim 12, wherein, On the same cross section of the stator core, the width of the slot opening of the stator slot is W, the center line between the width center of the slot opening of the stator slot and the center of the stator core is the second connecting line, and the included angle between the first connecting line and the second connecting line is α; on the same cross section of the rotor core, the center line between the geometric center of the third permanent magnet and the center of the rotor core is the fifth connecting line, the length of the fifth connecting line is L6, the included angle between the fifth connecting line and the d-axis is α3, the center line between the geometric center of the fourth permanent magnet and the center of the rotor core is the sixth connecting line, the length of the sixth connecting line is L7, the included angle between the sixth connecting line and the d-axis is α4, the width of the second permanent magnet is W2, the width of the sixth permanent magnet is W6, and the rotor core satisfies the following relationship: 0.077*L7 ≤ ≤0.21*L6 .

22. The electric machine of claim 21, wherein, The rotor core satisfies the following relationship: 0.115 * L7 ≤ ≤ 0.112 * L6 .

23. The electric machine of claim 12, wherein, On the same cross section of the stator core, the width of the slot opening of the stator slot is W, the center line between the width center of the slot opening of the stator slot and the center of the stator core is the second connecting line, and the included angle between the first connecting line and the second connecting line is α; on the same cross section of the rotor core, the center line between the geometric center of the fifth permanent magnet and the center of the rotor core is the seventh connecting line, the length of the seventh connecting line is L8, the included angle between the seventh connecting line and the d-axis is α5, the center line between the geometric center of the sixth permanent magnet and the center of the rotor core is the eighth connecting line, the length of the eighth connecting line is L9, the included angle between the eighth connecting line and the d-axis is α6, the width of the third permanent magnet is W3, the width of the sixth permanent magnet is W6, and the rotor core satisfies the following relationship: 0.083*L8 ≤ ≤0.28*L9 .

24. The electric machine of claim 23, wherein, The rotor core satisfies the following relationship: 0.146*L8 ≤ ≤0.121*L9 .

25. A vehicle characterized by The motor comprises the motor according to any one of claims 1-24. The motor comprises the motor according to any one of claims 1-24.

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