Motor rotor lamination and motor having the same

Abstract

The application provides a motor rotor lamination and a motor with the same. The motor rotor lamination comprises a lamination body, the lamination body has a plurality of magnetic poles, each magnetic pole is provided with a plurality of magnetic steel slot groups, the magnetic steel slot groups comprise a first slot group and a second slot group, the first slot group and the second slot group are arranged at intervals along a radial direction of the lamination body, and a weight-reducing slot is arranged between the first slot group and the second slot group. According to the technical scheme of the application, the strength of the motor rotor lamination can be improved and the loss can be reduced by arranging the weight-reducing slot, the technical problem of insufficient strength of the motor rotor in the prior art is solved, the mechanical performance of the rotor during high-speed operation is improved, the motor is facilitated to be high-speed, the torque density of the motor is increased, and the speed regulation performance of the motor is improved.

Description

Technical Field

[0001] This invention relates to the field of motor design technology, and more specifically, to a motor rotor lamination and a motor having the same. Background Technology

[0002] Permanent magnet assisted synchronous reluctance motors (PMRMs) possess high reluctance torque. With the assistance of permanent magnets, they not only improve the power factor but also increase the permanent magnet torque, thereby enhancing the combined torque. Compared to permanent magnet synchronous motors (PMSMs), PMRMs achieve higher power density and wider speed range with a smaller amount of magnets. Furthermore, their lower back electromotive force ensures the durability, lifespan, and reliability of the controller. Therefore, PMRMs will be increasingly used in drive motors for new energy vehicles, especially high-speed passenger cars.

[0003] To reduce structural size, weight, and raw material costs, and to improve power and torque density, the maximum speed limit of new energy drive motor rotors has gradually increased from 5000-8000 rpm a few years ago to 12000-15000 rpm. Early permanent magnet assisted reluctance motors had low speeds, and the rotor lamination strength was insufficient to meet the high-speed requirements. Furthermore, as motor speed and frequency increase, the high harmonic content, high losses, and low efficiency of permanent magnet assisted reluctance motors become increasingly prominent. Therefore, rotor lamination design research is particularly important.

[0004] There is currently no effective solution to the technical problem of insufficient rotor lamination strength mentioned above. Summary of the Invention

[0005] The main objective of this invention is to provide a motor rotor lamination and a motor having the same, so as to solve the technical problem of insufficient strength of rotor laminations in the prior art.

[0006] To achieve the above objectives, according to one aspect of the present invention, a motor rotor lamination is provided, comprising: a lamination body having a plurality of magnetic poles, each magnetic pole having a plurality of magnetic steel slot groups, the magnetic steel slot groups including a first slot group and a second slot group, the first slot group and the second slot group being spaced apart along the radial direction of the lamination body, and a weight reduction slot being provided between the first slot group and the second slot group.

[0007] Furthermore, the second slot group and the first slot group are arranged outward in the radial direction of the lamination body. The first slot group includes at least two first magnetic slots. The first magnetic slots extend outward in the radial direction of the lamination body. The two first magnetic slots are arranged symmetrically about the radial center line of the magnetic pole of the first slot group. A middle-spaced magnetic bridge is formed between the ends of each first magnetic slot on the side closest to the geometric center of the lamination body. The middle-spaced magnetic bridge includes a first bridge segment, a second bridge segment, and a third bridge segment arranged outward in the radial direction of the lamination body. At least two of the first bridge segment, the second bridge segment, and the third bridge segment have unequal widths.

[0008] Furthermore, the cross-sections of the first, second, and third bridge segments along the axial direction of the lamination body are all rectangular.

[0009] Furthermore, the width of the first bridge segment is less than the width of the second bridge segment, and the width of the first bridge segment is equal to the width of the third bridge segment.

[0010] Furthermore, the first bridge segment has a first length dB3 and a width L1, the third bridge segment has a third length dB1 and a width L1, and the second bridge segment has a second length dB4 and a second width L2, wherein 1.8dB1≤dB3≤1.9dB1, and / or 1.8L1≤L2≤2.2L1.

[0011] Furthermore, the second slot group includes two second magnet slots and one third magnet slot. The second magnet slots extend along the radial direction of the lamination body. The two second magnet slots are arranged about the radial center line of the magnetic pole where the second slot group is located. The third magnet slot is located between the ends of the two second magnet slots near the geometric center of the lamination body. The weight reduction slot is located between the third magnet slot and the first magnet slot. The third magnet slot is symmetrically arranged about the radial center line of the magnetic pole where the second slot group is located.

[0012] Furthermore, the weight reduction groove has a first groove side near the first magnet groove, a second groove side near the third magnet groove, and a third groove side connecting the first groove side and the second groove side. There are two third groove sides, and the first groove side and the second groove side are both arranged parallel to the third magnet groove.

[0013] Furthermore, the length of the first groove side is dD1, and the length of the second groove side is dD2, where 2.5dD1≤dD2≤3.5dD1.

[0014] Furthermore, the minimum distance between the first groove edge and the first magnet groove is d1, and the minimum distance between the second groove edge and the third magnet groove is d2, where 1.3d2≤d1≤1.35d2.

[0015] Furthermore, the lamination body is provided with multiple magnetic flux tidying grooves, which are located between two first magnet grooves and extend along the radial direction of the lamination body. The magnetic flux tidying grooves include two first magnetic flux tidying grooves and two second magnetic flux tidying grooves. The two second magnetic flux tidying grooves are symmetrically arranged about the radial center line of the magnetic pole of the first groove group. The first magnetic flux tidying grooves are located between the two second magnetic flux tidying grooves and are symmetrically arranged about the radial center line of the magnetic pole of the first groove group.

[0016] Furthermore, the minimum distance between the first magnetic flux tidying groove and the radial center line of the magnetic pole where the first groove group is located is dC1, and the minimum distance between the second magnetic flux tidying groove and the radial center line of the magnetic pole where the first groove group is located is dC2, wherein 7dC1≤dC2≤8dC1 and dC2<3mm.

[0017] Furthermore, the angle between the extension direction of the first magnetic flux tidying groove, the extension direction of the second magnetic flux tidying groove, and the radial center line of the magnetic pole where the first groove group is located is β, where 22°≤β≤25°.

[0018] Furthermore, the first slot group, the second slot group, the weight reduction slot, and the intermediate magnetic bridge are all symmetrically arranged about the radial center line of the magnetic poles where the first slot group, the second slot group, and the weight reduction slot are located.

[0019] According to another aspect of the present invention, an electric motor is provided, the electric motor including a motor rotor lamination, the motor rotor lamination being the aforementioned motor rotor lamination.

[0020] By applying the technical solution of this invention and setting a weight-reducing groove, the strength of the motor rotor laminations can be improved and the losses reduced, thus solving the technical problem of insufficient motor rotor strength in the prior art. While improving the mechanical performance of the rotor at high speed, it is also beneficial to the high speed of the motor, which can increase the torque density of the motor and improve the speed regulation performance of the motor. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 A schematic diagram of the structure of a first embodiment of the lamination body according to the present invention is shown;

[0023] Figure 2 A schematic diagram of the structure of a first embodiment of the intermediate-spaced magnetic bridge according to the present invention is shown;

[0024] Figure 3 A schematic diagram of a second embodiment of the intermediate magnetic bridge according to the present invention is shown;

[0025] Figure 4 A schematic diagram of an embodiment of the magnetic flux conditioning groove according to the present invention is shown;

[0026] Figure 5 A schematic diagram of the structure of a second embodiment of the lamination body according to the present invention is shown;

[0027] Figure 6a , Figure 6b A stress simulation comparison diagram is shown between the motor rotor lamination according to the present invention and the motor rotor lamination with an equal-width magnetic bridge in the prior art;

[0028] Figure 7a , Figure 7b A voltage simulation comparison diagram is shown between the motor rotor lamination according to the present invention and the motor rotor lamination without magnetic flux conditioning groove in the prior art;

[0029] Figure 8a , Figure 8b A stress simulation comparison diagram is shown between the motor rotor lamination according to the present invention and the motor rotor lamination without weight reduction grooves in the prior art.

[0030] The above figures include the following reference numerals:

[0031] 1. Film processing body;

[0032] 10. Magnet slot assembly; 11. First magnet slot; 12. Second magnet slot; 13. Third magnet slot;

[0033] 110. Intermediate magnetic bridge; 111. First bridge segment; 112. Second bridge segment; 113. Third bridge segment;

[0034] 20. Weight reduction groove; 21. First groove side; 22. Second groove side; 23. Third groove side;

[0035] 30. Magnetic beam sorting slot; 31. First magnetic beam sorting slot; 32. Second magnetic beam sorting slot. Detailed Implementation

[0036] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0037] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0038] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0039] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0040] Combination Figures 1 to 8b As shown, according to a specific embodiment of this application, a motor rotor lamination is provided.

[0041] Specifically, the motor rotor lamination includes a lamination body 1, which has multiple magnetic poles. Each magnetic pole has multiple magnetic steel slot groups 10. The magnetic steel slot groups 10 include a first slot group and a second slot group. The first slot group and the second slot group are spaced apart along the radial direction of the lamination body 1. A weight reduction slot 20 is provided between the first slot group and the second slot group.

[0042] By applying the technical solution of this embodiment and setting the weight reduction groove 20, the strength of the motor rotor lamination can be improved and the loss can be reduced, solving the technical problem of insufficient strength of the motor rotor in the prior art. While improving the mechanical performance of the rotor at high speed, it is also conducive to the high speed of the motor, which can increase the torque density of the motor and improve the speed regulation performance of the motor.

[0043] Furthermore, the second slot group and the first slot group are arranged outward in the radial direction of the lamination body 1. The first slot group includes at least two first magnetic slots 11, which extend in the radial direction of the lamination body 1. The two first magnetic slots 11 are symmetrically arranged about the radial center line L of the magnetic pole of the first slot group. A middle-spaced magnetic bridge 110 is formed between the ends of each first magnetic slot 11 on the side closest to the geometric center of the lamination body 1. The middle-spaced magnetic bridge 110 includes a first bridge segment 111, a second bridge segment 112, and a third bridge segment 113 arranged outward in the radial direction of the lamination body 1. At least two of the first bridge segments 111, the second bridge segment 112, and the third bridge segment 113 have unequal widths. By setting an intermediate magnetic bridge 110, the strength of the motor rotor lamination can be improved. By making at least two of the first bridge section 111, the second bridge section 112 and the third bridge section 113 have different widths, the wider part can enhance the magnetic bridge strength, and the narrower part can reduce leakage flux, thus balancing strength and performance.

[0044] Specifically, the cross-sections of the first bridge segment 111, the second bridge segment 112, and the third bridge segment 113 along the axial direction of the lamination body 1 are all rectangular. This ensures that the widths of the first bridge segment 111, the second bridge segment 112, and the third bridge segment 113 are constant, thereby ensuring that the magnetic bridge strength within each segment is constant.

[0045] It should be noted that the cross-sections of the first bridge segment 111, the second bridge segment 112, and the third bridge segment 113 along the axial direction of the stamping body 1 can also be in various shapes such as triangle, arc, trapezoid, and ellipse, and the cross-sectional shape can be modified according to actual needs.

[0046] Preferably, the width of the first bridge segment 111 is smaller than the width of the second bridge segment 112, and the width of the first bridge segment 111 is equal to the width of the third bridge segment 113. This allows the intermediate magnetic bridge 110 to form a structure that is larger in the middle and smaller at both ends. The wider middle section (i.e., the second bridge segment 112) can enhance the strength of the magnetic bridge, while the smaller ends (i.e., the first bridge segment 111 and the third bridge segment 113) can reduce leakage flux, thus balancing strength and performance.

[0047] The first bridge segment 111 has a first length dB3 and a width L1, the third bridge segment 113 has a third length dB1 and a width L1, and the second bridge segment 112 has a second length dB4 and a second width L2, wherein 1.8dB1≤dB3≤1.9dB1, and / or 1.8L1≤L2≤2.2L1. Limiting the width and length relationship among the first bridge segment 111, the third bridge segment 113, and the second bridge segment 112 balances the strength and performance of the motor rotor laminations, avoiding situations where the width portion is too large or too small, thus affecting the lamination performance. Figure 6a , Figure 6bThe following diagram shows a stress simulation comparison between the motor rotor lamination in this embodiment and the motor rotor lamination with an equal-width magnetic bridge in the prior art. Figure 6b As shown, the maximum stress of the motor rotor laminations with equal-width magnetic bridges is 500.35 MPa. Figure 6a As shown, the maximum stress of the motor rotor lamination in this embodiment is 446.42 MPa. The intermediate magnetic bridge 110 in this embodiment effectively reduces the stress and improves the lamination strength.

[0048] like Figure 3 As shown, in an exemplary embodiment of this application, the intermediate magnetic bridge 110 is symmetrically arranged about the radial center line L of the magnetic pole where the first slot group is located, and the two first magnetic slots 11 are completely symmetrically arranged about the radial center line L of their respective magnetic poles. The end of the first magnetic slot 11 near the geometric center of the lamination body 1 forms a first line segment B1, a second line segment B2, a third line segment B3, and a fourth line segment B4. The first line segment B1 and the third line segment B3 are on the same straight line. The third line segment B3 and the fourth line segment B4, as well as the first line segment B1 and the fourth line segment B4, are connected by the second line segment B2, so that a first bridge segment 111 is formed between the two third line segments B3, a third bridge segment 113 is formed between the two first line segments B1, and a second bridge segment 112 is formed between the two fourth line segments B4 and the oppositely arranged second line segments B2.

[0049] Preferably, the two second line segments B2 are arranged in parallel, the straight line containing the fourth line segment B4 and the straight line containing the first line segment B1 are both arranged in parallel with the radial center line L of the magnetic pole where the first slot group is located, and the straight line containing the second line segment B2 is perpendicular to the radial center line L, so that the second bridge segment 112 includes a groove extending in the radial direction along the lamination body 1, thereby making the width of the second bridge segment 112 greater than the width of the first bridge segment 111 and the third bridge segment 113. In this embodiment, the first length of the first bridge segment 111 is the length of the third line segment B3 (dB3), and the width of the first bridge segment 111 is the distance L1 between the two third line segments B3. The second length of the second bridge segment 112 is the length of the fourth line segment B4 (dB4), and the second width L2 of the second bridge segment 112 is the distance between the two fourth line segments B4, i.e., L2 = L1 + 2*dB2. The third length of the third bridge segment 113 is the length of the first line segment B1 (dB1), and the width of the third bridge segment 113 is the distance L1 between the two first line segments B1. In this embodiment, there are quantitative relationships: dB3 = 1.8dB1 ~ 1.9dB1, dB2 = 0.4L1 ~ 0.6L1.

[0050] Optionally, the second segment B2 can also be connected to the fourth segment B4 in a non-perpendicular manner, that is, the extensions of the two second segments B2 are set at an angle, so that the cross-section of the groove extending along the radial direction of the second bridge segment 112 along the lamination body 1 has a trapezoidal structure. Alternatively, the second segment B2 and the fourth segment B4 can be set as a single arc segment, which protrudes in a direction away from the radial center line L to form a groove. Or, the fourth segment B4 can be omitted, and the two second segments B2 intersect at a point to form a triangular groove. Depending on actual needs, the groove extending along the radial direction of the second bridge segment 112 along the lamination body 1 can be set in various ways.

[0051] In the above embodiments, the first line segment B1, the second line segment B2, the third line segment B3 and the fourth line segment B4 are all straight line segments. In alternative embodiments of this application, at least one of them can be set as an arc or a curve. For example, the second line segment B2 can be an arc segment, or the fourth line segment B4 can be an arc segment.

[0052] Furthermore, the second slot group includes two second magnet slots 12 and one third magnet slot 13. The second magnet slots 12 extend radially along the lamination body 1, and the two second magnet slots 12 are positioned about the radial center line of the magnetic pole of the second slot group. The third magnet slot 13 is positioned between the ends of the two second magnet slots 12 near the geometric center of the lamination body 1. A weight-reducing slot 20 is positioned between the third magnet slot 13 and the first magnet slot 11, and the third magnet slot 13 is symmetrically positioned about the radial center line of the magnetic pole of the second slot group. The weight-reducing slot 20, positioned between the third magnet slot 13 and the first magnet slot 11, improves the strength of the motor rotor and reduces losses.

[0053] like Figure 1 As shown, in this embodiment, two second magnet slots 12 and one third magnet slot 13 form a U-shaped slot group, and two first magnet slots 11 form a V-shaped slot group, forming a U+V rotor topology.

[0054] Specifically, the weight-reducing groove 20 has a first groove edge 21 near the first magnet groove 11, a second groove edge 22 near the third magnet groove 13, and a third groove edge 23 connecting the first groove edge 21 and the second groove edge 22. There are two third groove edges 23, and the first groove edge 21 and the second groove edge 22 are both arranged parallel to the third magnet groove 13. In this embodiment, the weight-reducing groove 20 has a trapezoidal structure, which can minimize the stress concentration effect of the weight-reducing groove 20 itself, while dispersing the stress borne by the intermediate magnetic bridge 110 and improving the structural strength.

[0055] Wherein, the length of the first groove edge 21 is dD1, and the length of the second groove edge 22 is dD2, wherein 2.5dD1≤dD2≤3.5dD1. By limiting the dimensional relationship between the lengths of the first groove edge 21 and the second groove edge 22, the stress-dispersing effect of the weight-reducing groove 20 can be maximized while reducing losses.

[0056] Specifically, the minimum distance between the first slot edge 21 and the first magnet slot 11 is d1, and the minimum distance between the second slot edge 22 and the third magnet slot 13 is d2, where 1.3d2≤d1≤1.35d2. The quantitative constraint relationship between d1 and d2 can improve the mechanical performance of the rotor when running at high speed, which is conducive to the high speed of the motor, increases the torque density of the motor, and improves the speed regulation performance of the motor.

[0057] Figure 8a , Figure 8b The diagram shows a stress simulation comparison between the motor rotor lamination according to this embodiment and the motor rotor lamination without weight reduction grooves in the prior art. Figure 8a As shown, the maximum stress of the motor rotor lamination in this embodiment is 374.78 MPa. Figure 8b As shown, the maximum stress of the motor rotor lamination without weight reduction grooves in the prior art is 408.77 MPa. In this embodiment, the motor rotor lamination effectively reduces the stress by setting weight reduction grooves.

[0058] Furthermore, the lamination body 1 is also provided with a plurality of magnetic flux tidying grooves 30. The magnetic flux tidying grooves 30 are disposed between two first magnet slots 11, and extend along the radial direction of the lamination body 1. The magnetic flux tidying grooves 30 include two first magnetic flux tidying grooves 31 and two second magnetic flux tidying grooves 32. The two second magnetic flux tidying grooves 32 are symmetrically arranged about the radial center line of the magnetic pole of the first slot group. The first magnetic flux tidying grooves 31 are disposed between the two second magnetic flux tidying grooves 32, and are symmetrically arranged about the radial center line of the magnetic pole of the first slot group. By setting the first magnetic flux tidying grooves 31 and the second magnetic flux tidying grooves 32, the motor can have a better magnetic field distribution, improve the sinusoidal nature of the air gap magnetic field, thereby reducing the harmonic content and loss of the motor and improving the motor efficiency.

[0059] like Figure 4 As shown, in this embodiment, the magnetic flux tidying groove 30 includes four rectangular grooves near the air gap side, wherein the radial length of the two second magnetic flux tidying grooves 32 is set to be greater than the radial length of the first magnetic flux tidying groove 31.

[0060] Specifically, the minimum distance between the first magnetic flux stabilizing groove 31 and the radial center line of the magnetic pole where the first groove group is located is dC1, and the minimum distance between the second magnetic flux stabilizing groove 32 and the radial center line of the magnetic pole where the first groove group is located is dC2, wherein 7dC1≤dC2≤8dC1 and dC2<3mm. By limiting the distance between the first magnetic flux stabilizing groove 31 and the radial center line L, and the distance between the second magnetic flux stabilizing groove 32 and the radial center line L, the magnetic field lines are more uniformly distributed, and the sinusoidal nature of the air gap magnetic field is improved.

[0061] In this embodiment, the angle between the extending direction of the first magnetic flux tidying groove 31, the extending direction of the second magnetic flux tidying groove 32, and the radial center line of the magnetic pole where the first groove group is located is β, wherein 22°≤β≤25°. That is to say, in this embodiment, the extending directions of the first magnetic flux tidying groove 31 and the extending directions of the second magnetic flux tidying groove 32 are parallel.

[0062] Figure 7a , Figure 7b A voltage simulation comparison diagram is shown between the motor rotor lamination according to this embodiment and the motor rotor lamination without magnetic flux conditioning slots in the prior art. With the application of magnetic flux conditioning slots, the motor harmonic content decreased from 7.3% to 2.8%.

[0063] Preferably, the first slot group, the second slot group, the weight reduction slot 20, and the intermediate magnetic bridge 110 are all symmetrically arranged about the radial center line of the magnetic poles where the first slot group, the second slot group, and the weight reduction slot 20 are located. This makes the structure of the lamination body 1 more stable and the motor rotor performance better.

[0064] According to another specific embodiment of this application, a motor is also provided, the motor including motor rotor laminations, the motor rotor laminations being the motor rotor laminations in the above embodiments. Applying the technical solutions in the above embodiments, the motor harmonic content is reduced from 7.3% to 2.8%; the maximum rotor stress is reduced from 500MPa to 374MPa, effectively reducing harmonic content, improving motor efficiency and rotor strength, and increasing motor rotor strength while reducing losses and improving motor performance. This solves the problems of insufficient rotor lamination strength, high motor harmonic content, high losses, and low efficiency in drive motors at high speeds.

[0065] Preferably, the motor is a permanent magnet assisted synchronous reluctance motor, which can be used in new energy vehicles as a drive motor for high-speed passenger vehicles.

[0066] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0067] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0068] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0069] 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 motor rotor lamination, characterized in that, include: The lamination body (1) has multiple magnetic poles, and multiple magnetic steel groove groups (10) are opened on each magnetic pole. The magnetic steel groove group (10) includes a first groove group and a second groove group. The first groove group and the second groove group are spaced apart along the radial direction of the lamination body (1). A weight reduction groove (20) is provided between the first groove group and the second groove group. The second slot group and the first slot group are arranged outward in the radial direction of the lamination body (1). The first slot group includes at least two first magnetic slots (11). The first magnetic slots (11) extend in the radial direction of the lamination body (1). The two first magnetic slots (11) are arranged symmetrically about the radial center line of the magnetic pole of the first slot group. A middle-spaced magnetic bridge (110) is formed between the ends of each first magnetic slot (11) on the side close to the geometric center of the lamination body (1). The middle-spaced magnetic bridge (110) includes a first bridge segment (111), a second bridge segment (112) and a third bridge segment (113) arranged outward in the radial direction of the lamination body (1). At least two of the first bridge segment (111), the second bridge segment (112) and the third bridge segment (113) have unequal widths. The first bridge segment (111) has a width L1, the third bridge segment (113) has a width L1, and the second bridge segment (112) has a second width L2, wherein 1.8 L1≤L2≤2.2 L1.

2. The motor rotor lamination according to claim 1, characterized in that, The first bridge segment (111), the second bridge segment (112), and the third bridge segment (113) all have rectangular cross sections along the axial direction of the lamination body (1).

3. The motor rotor lamination according to claim 1 or 2, characterized in that, The width of the first bridge segment (111) is less than the width of the second bridge segment (112), and the width of the first bridge segment (111) is equal to the width of the third bridge segment (113).

4. The motor rotor lamination according to claim 1 or 2, characterized in that, The first bridge segment (111) has a first length dB3, the third bridge segment (113) has a third length dB1, and the second bridge segment (112) has a second length dB4, wherein 1.8 dB1 ≤ dB3 ≤ 1.9 dB1.

5. The motor rotor lamination according to claim 1, characterized in that, The second slot group includes two second magnet slots (12) and one third magnet slot (13). The second magnet slots (12) extend along the radial direction of the lamination body (1). The two second magnet slots (12) are arranged about the radial center line of the magnetic pole where the second slot group is located. The third magnet slot (13) is arranged between the ends of the two second magnet slots (12) near the geometric center of the lamination body (1). The weight reduction slot (20) is arranged between the third magnet slot (13) and the first magnet slot (11). The third magnet slot (13) is symmetrically arranged about the radial center line of the magnetic pole where the second slot group is located.

6. The motor rotor lamination according to claim 5, characterized in that, The weight reduction groove (20) has a first groove edge (21) near the first magnet groove (11), a second groove edge (22) near the third magnet groove (13), and a third groove edge (23) connecting the first groove edge (21) and the second groove edge (22). There are two third groove edges (23), and the first groove edge (21) and the second groove edge (22) are both arranged parallel to the third magnet groove (13).

7. The motor rotor lamination according to claim 6, characterized in that, The length of the first groove edge (21) is dD1, and the length of the second groove edge (22) is dD2, wherein 2.5 dD1≤dD2≤3.5dD1.

8. The motor rotor lamination according to claim 6 or 7, characterized in that, The minimum distance between the first groove edge (21) and the first magnet groove (11) is d1, and the minimum distance between the second groove edge (22) and the third magnet groove (13) is d2, wherein 1.3d2≤d1≤1.35d2.

9. The motor rotor lamination according to claim 1, characterized in that, The lamination body (1) is also provided with a plurality of magnetic flux tidying grooves (30), which are disposed between two of the first magnet grooves (11) and extend along the radial direction of the lamination body (1). The magnetic flux tidying groove (30) includes two first magnetic flux tidying grooves (31) and two second magnetic flux tidying grooves (32). The two second magnetic flux tidying grooves (32) are symmetrically arranged about the radial center line of the magnetic pole where the first groove group is located. The first magnetic flux tidying grooves (31) are arranged between the two second magnetic flux tidying grooves (32). The two first magnetic flux tidying grooves (31) are symmetrically arranged about the radial center line of the magnetic pole where the first groove group is located.

10. The motor rotor lamination according to claim 9, characterized in that, The minimum distance between the first magnetic flux tidying groove (31) and the radial center line of the magnetic pole where the first groove group is located is dC1, and the minimum distance between the second magnetic flux tidying groove (32) and the radial center line of the magnetic pole where the first groove group is located is dC2, wherein 7dC1≤dC2≤8dC1 and dC2<3mm.

11. The motor rotor lamination according to claim 9 or 10, characterized in that, The angle between the extension direction of the first magnetic flux tidying groove (31), the extension direction of the second magnetic flux tidying groove (32), and the radial center line of the magnetic pole where the first groove group is located is β, wherein 22°≤β≤25°.

12. The motor rotor lamination according to claim 1, characterized in that, The first slot group, the second slot group, the weight reduction slot (20), and the intermediate magnetic bridge (110) are all symmetrically arranged about the radial center line of the magnetic poles where the first slot group, the second slot group, and the weight reduction slot (20) are located.

13. An electric motor, the electric motor comprising motor rotor laminations, characterized in that, The motor rotor lamination is the motor rotor lamination as described in any one of claims 1-12.

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