Rotor lamination, rotor lamination core, rotor, electric machine and vehicle

Abstract

The invention discloses a rotor lamination for a rotor of an electric machine, comprising a plurality of channel openings, each being used to form a magnet cavity of a rotor lamination core for accommodating a magnet, wherein the plurality of channel openings comprise channel opening pairs, each formed by two channel openings adjacent in a circumferential direction and axially symmetrical with respect to a radial axis of symmetry, and a respective channel opening in the respective channel opening pairs has a first longitudinal side and a second longitudinal side parallel to the first longitudinal side; wherein each channel opening has an outer contour connecting end portions of the first longitudinal side and the second longitudinal side to each other away from the radial axis of symmetry; and the channel opening has a material hollowed-out portion at a connection portion formed by the outer contour and the first longitudinal side.

Description

[0001] ROTOR LAMINATION, ROTOR LAMINATION CORE, ROTOR, ELECTRIC MACHINE AND VEHICLE

[0002] TECHNICAL FIELD

[0003] The present disclosure relates to the field of electric machines, and relates more specifically to a rotor lamination for a rotor of an electric machine, further to a rotor lamination core including such a rotor lamination, and further to a corresponding rotor, an electric machine and a vehicle.

[0004] BACKGROUND

[0005] Generally, a rotor for an electric machine includes a rotor lamination core formed by rotor laminations and a plurality of permanent magnets, which may be arranged in magnet cavities formed in the rotor lamination core. The magnet cavities may be arranged in pairs, and each pair of magnet cavities may be arranged more specifically in a V-shape. The magnet cavities in each pair may be axially symmetrical with respect to a corresponding radial axis of symmetry.

[0006] During operation of the rotor, the rotor laminations sometimes have to withstand large mechanical loads, especially in electric machines used extensively in automotive applications. These large mechanical loads are caused in particular by volume forces or centrifugal forces acting on the rotor laminations during rotation and additional surface loads acting on the rotor laminations due to the permanent magnets being arranged in the magnet cavities of the rotor and supported to resist radial displacement. This combination of loads leads to a local peak value of mechanical stress on the rotor laminations at the radial outer contour of the magnet cavity, which may cause the rotor laminations to rupture at the radial contour of the magnet cavities, thereby affecting the performance of the corresponding rotor lamination core, rotor or electric machine. In the prior art, in order to overcome the technical problem, the common practice is to increase the thickness of the rotor laminations at the peak of the mechanical stress. However, the increase in thickness makes the laminations heavier, which has an adverse effect on the rotor torque, reduces the working efficiency of the rotor, and also leads to material waste. Moreover, the increase in thickness does not effectively avoid stress concentration.

[0007] An objective of the present disclosure is to propose a new rotor lamination that can effectively overcome the problems in the prior art.

[0008] SUMMARY

[0009] To this end, the present disclosure proposes a rotor lamination for a rotor of an electric machine. According to an embodiment, the rotor lamination comprises a plurality of channel openings, each channel opening being used to form a magnet cavity of a rotor lamination core for accommodating a magnet, wherein the plurality of channel openings comprise channel opening pairs, each formed by two channel openings adjacent in a circumferential direction and axially symmetrical with respect to a radial axis of symmetry, and a respective channel opening in the respective channel opening pairs has a first longitudinal side and a second longitudinal side parallel to the first longitudinal side; wherein each channel opening has an outer contour connecting end portions of the first longitudinal side and the second longitudinal side to each other away from the radial axis of symmetry; and wherein the channel opening has a material hollowed-out portion at a connection portion formed by the outer contour and the first longitudinal side.

[0010] Therefore, in the present disclosure, since the outer contour is provided to connect the end portions, away from the radial axis of symmetry, of the first longitudinal side and the second longitudinal side of the channel opening forming the magnet cavity to each other, and the channel opening has the material hollowed- out portion at the connection portion formed by the outer contour and the first longitudinal side, the tangential dimension of the channel opening at the end portions can be extended, and thus the stress is allowed to be dispersed on a larger surface, thereby effectively eliminating stress concentration and improving the bearing capacity of the rotor lamination at the end portions of the channel opening for the above-mentioned loads, especially the centrifugal force at high-speed rotation. In addition, the presence of the material hollowed-out portion allows the weight of the rotor lamination to be reduced, which is beneficial to the torque and working efficiency of the rotor.

[0011] According to various embodiments, the rotor lamination proposed by the present disclosure may further comprise one or more of the following further developments.

[0012] In some embodiments, the first longitudinal side is arranged closer to the radial axis of symmetry than the second longitudinal side.

[0013] In some embodiments, the material hollowed-out portion is bounded by a first boundary, a second boundary and an arc-shaped boundary, wherein: the first boundary constitutes a part of a circumferential extension portion of the outer contour; the second boundary forms an angle with the first longitudinal side; and the arc-shaped boundary connects the first boundary and the second boundary.

[0014] In some embodiments, the angle is in a range of 0 to 90°.

[0015] In some embodiments, the material hollowed-out portion has a bean-like shape.

[0016] In some embodiments, the first boundary smoothly extends from the remaining part of the circumferential extension portion of the outer contour.

[0017] In some embodiments, the second boundary and the first longitudinal side have a rounded transition portion therebetween.

[0018] In some embodiments, the arc-shaped boundary is smoothly connected to the first boundary and the second boundary.

[0019] In some embodiments, the channel opening pairs are arranged in a V-shape that opens radially outwards.

[0020] In some embodiments, the channel opening pairs comprise radially inner channel opening pairs and radially outer channel opening pairs that are arranged radially on the outside with respect to the radially inner channel opening pairs.

[0021] Another aspect of the present disclosure relates to a rotor lamination core for an electric machine, comprising a plurality of rotor laminations arranged in an axially layered manner, each being the rotor lamination according to any one of the above embodiments.

[0022] Another aspect of the present disclosure relates to a rotor, comprising the rotor lamination core as described above, wherein the rotor further comprises magnets arranged in the magnet cavities.

[0023] Another aspect of the present disclosure relates to an electric machine, comprising a stator and the rotor as described above, wherein the rotor is rotatably mounted with respect to the stator.

[0024] The present disclosure further relates to a vehicle comprising the electric machine as described above.

[0025] BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to describe the technical solutions provided by embodiments of the present disclosure more clearly, the drawings required by the embodiments will be briefly described below. It should be understood that the following drawings show only some embodiments of the present disclosure and should not be construed as limiting the scope of the present disclosure, and that those of ordinary skill in the art, without inventive effort, can further obtain other relevant drawings on the basis of these drawings. In the drawings:

[0027] FIG. 1 is a plan view of a rotor lamination for a rotor of an electric machine according to an embodiment;

[0028] FIG. 2 is a partial plan view of the rotor lamination described in FIG. 1 ; and

[0029] FIG. 3 is a partial cross-sectional view along a rotor lamination core of a rotor for an electric machine according to an embodiment, the cross-sectional view being taken in a direction perpendicular to a rotation axis of the rotor.

[0030] DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Hereinafter, a rotor lamination for a rotor of an electric machine according to an embodiment of the present disclosure will be described in detail with reference to the drawings. To make the objectives, technical solutions, and advantages of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be explained clearly and completely below with reference to the drawings for the embodiments of the present disclosure. Obviously, the described embodiments are only some, not all, embodiments of the present disclosure.

[0032] Therefore, a detailed description of the embodiments of the present disclosure, provided below with reference to the drawings, rather than being intended to limit the scope of the present disclosure for which protection is claimed, merely represents selected embodiments of the present disclosure. All other embodiments obtained by those of ordinary skill in the art on the basis of the described embodiments of the present disclosure without making inventive efforts also fall into the scope of protection of the present disclosure.

[0033] Unless otherwise defined in the context, a singular form includes its plural form. Throughout this specification, the terms "comprising", "having", etc. are used herein to specify the existence of the mentioned characteristic, number, step, operation, element, component or combination thereof, without ruling out the existence or addition of one or more other characteristics, numbers, steps, operations, elements, components or combinations thereof.

[0034] In addition, although terms including ordinal numbers such as "f i rst", " second ", etc. may be used to describe various components, these components are not limited by these terms, which are merely used only to differentiate one element from another. For example, without departing from the scope of the present disclosure, a first component may be referred to as a second component and, similarly, a second component may be referred to as a first component.

[0035] In the description of the present invention, it must be understood that orientational or positional relationships indicated by the terms "upper", "lower", "left," "right," "inner," "outer," etc. are based on the orientational or positional relationships shown in the drawings, or are the orientational or positional relationships in which the disclosed product is usually placed when used, or are the orientational or positional relationships commonly understood by those skilled in the art, and are merely intended to facilitate and simplify description of the present disclosure, rather than indicating or implying that the device or element in question must have a specific orientation or be constructed and operated in a specific orientation, and thus should not be construed as limiting the present disclosure.

[0036] As shown in FIGS. 1-3, the present disclosure proposes a rotor lamination 10 for a rotor of an electric machine, and the rotor lamination 10 is, for example, of a generally circular structure as a whole. According to an embodiment, the rotor lamination 10 is provided with a plurality of channel openings 100, 200. Each of the plurality of channel openings 100, 200 is used to form a magnet cavity of a rotor lamination core 1 for accommodating a magnet (not shown). More specifically, a plurality of rotor laminations 10 may be stacked axially to form the rotor lamination core 1 for the rotor. When the plurality of rotor laminations 10 are stacked axially, the corresponding channel openings 100, 200 of the rotor laminations are aligned with each other between the rotor laminations 10 to form magnet cavities, and the magnet cavities can be used to accommodate corresponding permanent magnets constituting the rotor. The plurality of channel openings 100, 200 of the rotor lamination 10 may be arranged to include channel opening pairs PI, PO, each formed by two channel openings adjacent in a circumferential direction and axially symmetrical with respect to a radial axis of symmetry RA, and a corresponding channel opening 100, 200 in each channel opening pair PI, PO has a first longitudinal side 110, 210 and a second longitudinal side 120, 220 parallel to the first longitudinal side 110, 210. Each channel opening 100, 200 has an outer contour 130, 230 that connects end portions of the first longitudinal side 110, 210 and the second longitudinal side 120, 220 to each other away from the radial axis of symmetry RA. More specifically, as shown in the figures, the channel opening 100, 200 may have a material hollowed-out portion 140, 240 at a connection portion formed by the outer contour 130, 230 and the first longitudinal side 110, 210. More specifically, the material hollowed-out portion 140, 240 constitutes a part of the corresponding channel opening 100, 200. More specifically, the material hollowed-out portion 140, 240 constitutes a tangential extension portion of the corresponding channel opening 100, 200 at the corresponding end portion.

[0037] Without limitation, a rotor lamination 10 may be provided with at least four, preferably at least six, channel opening pairs PI, PO, and all the channel opening pairs PI, PO may be arranged equidistantly from each other in a circumferential manner, that is, uniformly arranged in a circumferential direction.

[0038] In the sense of this document, "longitudinal" refers to the "main extension direction" of a corresponding structure, i.e., a length direction. For example, as shown in FIGS. 1-2, the length of the first longitudinal side 110, 210 or the second longitudinal side 120, 220 of the channel opening 100, 200 is significantly greater than the distance between the first longitudinal side 110, 210 and the second longitudinal side 120, 220.

[0039] In the sense of this document, "radial" refers to a direction along the radius of a generally circular or elliptical structure, the direction from the centre of the structure to the outside of the structure is "radially outwards", and the direction from the outside of the structure to the centre of the structure is "radially inwards".

[0040] Therefore, in the present disclosure, since the outer contour 130, 230 is provided to connect the end portions, away from the radial axis of symmetry RA, of the first longitudinal side 110, 210 and the second longitudinal side 120, 220 of the channel opening 100, 200 forming the magnet cavity to each other, and the channel opening 100, 200 has the material hollowed-out portion 140, 240 at the connection portion formed by the outer contour 130, 230 and the first longitudinal side 110, 210, the tangential dimension of the channel opening 100, 200 at the end portions can be extended, and thus the stress is allowed to be dispersed on a larger surface, thereby effectively eliminating stress concentration and improving the bearing capacity of the rotor lamination 10 at the end portions of the channel opening 100, 200 for the above-mentioned loads, especially the centrifugal force at high-speed rotation. In addition, the presence of the material hollowed-out portion 140, 240 allows the weight of the rotor laminations 10 to be reduced, which is beneficial to the torque and working efficiency of the rotor.

[0041] More specifically, compared with conventional rotor laminations, the rotor lamination 10 proposed by the present disclosure can advantageously reduce the local maximum value of the mechanical stress in the end portion region. In the case where the rotor laminations have the same mechanical stress resistance, the rotor lamination proposed by the present disclosure can firstly withstand higher volume forces, especially higher volume forces caused by higher rotation speeds, and secondly withstand higher surface forces, especially higher surface forces caused by the use of higher power and heavier permanent magnets. Alternatively, assuming that the same surface and physical forces occur, lower-cost and less stress-resistant materials can be used.

[0042] As shown in FIG. 1, according to a more specific embodiment, the first longitudinal side 110, 210 of a corresponding channel opening 100, 200 in the rotor lamination 10 is arranged closer to the radial axis of symmetry RAthan the second longitudinal side 120, 220 thereof. In such an embodiment, as shown in FIGS. 1- 3, the material hollowed-out portion 140, 240 of the corresponding channel opening 100, 200 is arranged to protrude towards the corresponding radial axis of symmetry RA.

[0043] As shown in FIGS. 1-2, in some embodiments, the channel opening pairs PI, PO in the rotor lamination may be arranged in a V-shape that opens radially outwards. In such an embodiment, end portions, away from the radial axis of symmetry RA, of the first longitudinal side 110, 210 and the second longitudinal side 120, 220 of the corresponding channel opening 100, 200, are end portions located radially on the outside. This is particularly advantageous for improving the centrifugal force-bearing capacity of the rotor lamination 10 at the radially outer end portion.

[0044] As shown in FIG. 2, in some embodiments, a corresponding material hollowed-out portion 140, 240 is defined by a first boundary 141, 241, a second boundary 142, 242, and an arc-shaped boundary 143, 243, wherein: the first boundary 141, 241 constitutes a part of a circumferential extension portion of the outer contour 130, 230; the second boundary 142, 242 extends from the first longitudinal side 110, 210 at an angle to the extension direction of the first longitudinal side 110, 210; and the arc-shaped boundary 143, 243 connects the first boundary 141, 241 and the second boundary 142, 242. The arrangement of the arcshaped boundary 143, 243 avoids the generation of a stress concentration portion. More specifically, the arc-shaped boundary 143, 243 is arranged to be smoothly connected to the first boundary 141, 241 and the second boundary 142, 242. More specifically, the first boundary 141, 241 is arranged to smoothly extend from the remaining part of the circumferential extension portion of the outer contour 130, 230. More specifically, the second boundary 142, 242 is arranged to have a rounded transition portion with the first longitudinal side 110, 210. Such an arrangement allows for more effective dispersion of the forces applied to the outer contour 130, 230, avoiding the generation of the stress concentration portion. More specifically, the second boundary 142, 242 is arranged to form an angle al, a2 in the range of 0 to 90° with the first longitudinal side 110, 210. More specifically, the angle al, a2 is in the range of 45° to 90°, for example, about 60°.

[0045] In a specific embodiment, as shown in FIGS. 1-3, the material hollowed-out portion 140, 240 may be arranged to have a bean-like shape as a whole. The setting of the bean-like shape avoids any sharp portions in the contours constituting the material hollowed-out portion 140, 240, thereby avoiding the presence of stress concentration portions. In addition, the bean-like shape allows the material hollowed-out portion 140, 240 to have a larger size at the circumferentially outermost end, that is, its contour line at the circumferentially outermost end is extended, thereby increasing the surface area that can absorb force.

[0046] In some embodiments, as shown in FIGS. 1-3, the second longitudinal side 120, 220 of a corresponding channel opening 100, 200 has an inwardly recessed portion 150, 250 at an end portion close to the outer contour 130, 230, and the inwardly recessed portion 150, 250 is shorter than the remaining part of the second longitudinal side 120, 220 from the extension line of the first longitudinal side 110, 210, so that a shoulder portion 160, 260 can be formed between the inwardly recessed portion 150, 250 and the remaining part of the second longitudinal side 120, 220. Such a shoulder portion 160, 260 may be beneficial to the retention of the permanent magnet. In addition, in an embodiment where the first longitudinal side 110, 210 of the channel opening 100, 200 is arranged closer to the corresponding radial axis of symmetry RA than the second longitudinal side 120, 220, the arrangement of such a shoulder portion 160, 260 avoids the problem of local weakening of the rotor lamination 10 caused by too little rotor lamination material, for example too narrow circumferential width, between the circumferentially adjacent second longitudinal sides 120, 220 of two circumferentially adjacent channel opening pairs PI, PO.

[0047] In some embodiments, as shown in FIG. 1 , the channel opening pairs PI, PO of the rotor lamination 10 may include a radially inner channel opening pair PI and a radially outer channel opening pair PO arranged radially on the outside with respect to the corresponding radially inner channel opening pair PI. In a specific embodiment, the longitudinal length of the channel opening 200 in the radially outer channel opening pair PO is less than the longitudinal length of the channel opening 100 in the radially inner channel opening pair PI.

[0048] The present disclosure further relates to a rotor lamination core 1 for a rotor of an electric machine. As shown in FIG. 3, the rotor lamination core 1 includes a plurality of rotor laminations arranged in an axially layered manner, each being the rotor lamination 10 according to any one of the above embodiments. More specifically, the rotor laminations 10 each include a centre hole 170, and are stacked axially so that the centre holes 170 of the plurality of rotor laminations communicate with each other, thereby forming a central through hole in which, for example, a mating shaft (not shown) may be received.

[0049] The present disclosure further relates to a rotor for an electric machine. The rotor includes the rotor lamination core 1 as described above, wherein the rotor further includes magnets arranged in the magnet cavities.

[0050] The present disclosure further relates to an electric machine. The electric machine includes a stator and the rotor as described above, wherein the rotor is rotatably mounted with respect to the stator.

[0051] The present disclosure further relates to a vehicle. The vehicle includes the electric machine as described above.

[0052] Exemplary implementations of the rotor lamination for the rotor of the electric machine proposed by the present invention have been described in detail above with reference to the preferred embodiments. However, it can be understood by those skilled in the art that, without departing from the concept of the present invention, various modifications and variations can be made to the above specific embodiments, and various technical features and structures proposed by the present invention can be combined in various ways without exceeding the scope of protection of the present invention.

[0053] The scope of the present disclosure is not defined by the embodiments described above but is defined by the attached claims and their equivalent scope.

Claims

WHAT IS CLAIMED IS:

1. A rotor lamination (10), comprising a plurality of channel openings (100; 200), each channel opening (100; 200) being used to form a magnet cavity of a rotor lamination core for accommodating a magnet, wherein the plurality of channel openings (100; 200) comprise channel opening pairs (PI; PO), each formed by two channel openings adjacent in a circumferential direction and axially symmetrical with respect to a radial axis of symmetry (RA), and a respective channel opening (100; 200) in the respective channel opening pairs (PI; PO) has a first longitudinal side (110; 210) and a second longitudinal side (120; 220) parallel to the first longitudinal side (110; 210); wherein each channel opening (100; 200) has an outer contour (130; 230) connecting end portions of the first longitudinal side (110; 210) and the second longitudinal side (120; 220) to each other away from the radial axis of symmetry (RA); and wherein the channel opening (100; 200) has a material hollowed-out portion (140; 240) at a connection portion formed by the outer contour (130; 230) and the first longitudinal side (110; 210).

2. The rotor lamination (10) according to Claim 1, wherein the first longitudinal side (110; 210) is arranged closer to the radial axis of symmetry (RA) than the second longitudinal side (120; 220).

3. The rotor lamination (10) according to Claim 1 or 2, wherein the material hollowed-out portion (140; 240) is bounded by a first boundary (141; 241), a second boundary (142; 242) and an arc-shaped boundary (143; 243), wherein the first boundary (141; 241) constitutes a part of a circumferential extension portion of the outer contour (130; 230); the second boundary (142; 242) forms an angle (al; a2) with the first longitudinal side (110; 210); and the arc-shaped boundary (143; 243) connects the first boundary (141; 241) and the second boundary (142; 242).

4. The rotor lamination (10) according to Claim 3, wherein the angle (al; a2)is in a range of 0 to 90°.

5. The rotor lamination (10) according to Claim 3, wherein the material hollowed-out portion (140; 240) has a bean-like shape.

6. The rotor lamination (10) according to Claim 3, wherein the first boundary (141; 241) smoothly extends from the remaining part of the circumferential extension portion of the outer contour (130; 230).

7. The rotor lamination (10) according to Claim 3, wherein the second boundary (142; 242) and the first longitudinal side (110; 210) have a rounded transition portion therebetween.

8. The rotor lamination (10) according to Claim 3, wherein the arc-shaped boundary (143; 243) is smoothly connected to the first boundary (141; 241) and the second boundary (142; 242).

9. The rotor lamination (10) according to Claim 1 or 2, wherein the channel opening pairs (PI; PO) are arranged in a V-shape that opens radially outwards.

10. The rotor lamination (10) according to Claim 1 or 2, wherein the channel opening pairs comprise radially inner channel opening pairs (PI) and radially outer channel opening pairs (PO) that are arranged radially on the outside with respect to the radially inner channel opening pairs.

11. A rotor lamination core (1), comprising a plurality of rotor laminations arranged in an axially layered manner, each being the rotor lamination (10) according to any one of Claims 1 to 10.

12. A rotor, comprising the rotor lamination core (1) according to Claim 11, wherein the rotor further comprises magnets arranged in the magnet cavities.

13. An electric machine, comprising a stator and the rotor according to Claim 12, wherein the rotor is rotatably mounted with respect to the stator.

14. A vehicle, comprising the electric machine according to Claim 13.

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