Oil-cooled stator punching sheet, motor and automobile electric drive system

Abstract

The invention discloses an oil cooling stator punching sheet, a motor and an automobile electric drive system, and relates to the technical field of motor cooling, the oil cooling stator punching sheet comprises a first layer oil cooling structure and a second layer stress buffer structure which are arranged from outside to inside, the first layer oil cooling structure comprises a plurality of first square holes which are uniformly distributed along the circumferential direction, and the second layer stress buffer structure comprises a plurality of second square holes which are uniformly distributed along the circumferential direction; a first partition rib is arranged between every two adjacent first square holes; the second-layer stress buffer structure comprises a plurality of second square holes which are uniformly distributed in the circumferential direction, and second partition ribs are arranged between the adjacent second square holes; the first partition ribs correspond to the middle positions of the second square holes, the second partition ribs correspond to the middle positions of the first square holes, and when interference magnitude stress is generated outside, the first partition ribs disperse the stress to the second partition ribs on the two sides of the second square holes. According to the invention, the interference stress of the casing and the stator core can be effectively absorbed, and the stress is prevented from being transmitted to a magnetic circuit part in the stator core; and the stress is only absorbed at the oil cooling structure, so that the stress loss is reduced, and the electric driving efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of motor cooling, in particular to an oil-cooled stator lamination, a motor and an automobile electric drive system. BACKGROUND

[0002] In order to improve the continuous output capability of the electric drive system of the new energy vehicle, the motor cooling technology has been a general trend from the traditional liquid cooling to the oil cooling. At present, most of the technical solutions are to make a hollow shaft on the rotor, and then to throw out oil through the rotor dynamic balance plate; and the stator cooling is usually to open oil holes on the stator core, and to form a radial rotating cooling oil path by the rotary pressure of the stator core. In addition to the existing magnetic steel segmentation technology and the use of thinner silicon steel sheet thickness, another core capability of the electric drive system of the new energy vehicle, the CLTC working condition efficiency, is also continuously improved. How to further improve the efficiency from the hardware design scheme needs to be combined with the oil cooling scheme.

[0003] In the prior art, the oil-cooled stator cooling scheme usually opens a square hole around the outer diameter of the stator core, for example, a kind of stator lamination includes a ring-shaped lamination body and a plurality of bosses, the inner side of the ring-shaped lamination body is provided with a plurality of stator slots, an oil hole is formed in the boss, and a recess is arranged between adjacent bosses; a kind of motor stator includes a plurality of stator laminations, the stator lamination is provided with oil guide holes arranged along the circumferential direction, and an oil inlet groove is formed on the outer circumferential wall of the stator lamination. The above-mentioned scheme can only solve the problem of structural design of oil cooling, and the stress generated by the interference between the stator core and the shell will be directly transmitted to the magnetic path area of the stator core in the radial direction, resulting in increased loss and reduced efficiency of the electric drive. SUMMARY

[0004] In view of the deficiencies in the prior art, the purpose of the present application is to provide an oil-cooled stator lamination, a motor and an automobile electric drive system, which can effectively absorb the interference stress between the shell and the stator core, avoid the transmission of stress to the magnetic path part inside the stator core, and only absorb stress at the oil cooling structure to reduce stress loss and improve the efficiency of the electric drive.

[0005] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme: In a first aspect, the embodiments of the present application provide an oil-cooled stator lamination, which comprises a first layer of oil cooling structure and a second layer of stress buffering structure arranged from outside to inside, the first layer of oil cooling structure comprises a plurality of first square holes uniformly distributed along the circumferential direction, and a first partition rib is arranged between adjacent first square holes; the second layer of stress buffering structure comprises a plurality of second square holes uniformly distributed along the circumferential direction, and a second partition rib is arranged between adjacent second square holes. The first partition rib corresponds to the middle position of the second square hole, and the second partition rib corresponds to the middle position of the first square hole, when the external interference stress is generated, the first partition rib disperses the stress to the second partition rib on both sides of the second square hole.

[0006] As a further implementation, the first layer oil cooling structure and the second layer stress buffering structure are misaligned in the circumferential direction by an angle of .

[0007] As a further implementation, the width between the first layer oil cooling structure and the second layer stress buffering structure is d, and the radial width of the first square hole is n1; wherein d≥0.8 n1.

[0008] As a further implementation, the circumferential width of the first square hole is m1, and m1=c d1, wherein d1 is the width of the first partition rib, and c is a constant.

[0009] As a further implementation, the width of the second partition rib is d2, and d2=d1.

[0010] As a further implementation, the inside of the second layer stress buffering structure is sequentially provided with an electromagnetic area yoke and an electromagnetic area tooth, the electromagnetic area teeth are uniformly distributed in the circumferential direction, and an electromagnetic area slot is arranged between adjacent electromagnetic area teeth.

[0011] As a further implementation, the number of the first square holes is 1-1.5 times the number of the electromagnetic area slots.

[0012] As a further implementation, the number and size of the second square holes are the same as those of the first square holes.

[0013] As a further implementation, the second square holes and the first square holes are independent of each other in the radial direction. Alternatively, the second square holes and the first square holes are in communication in the radial direction, forming a Z-shaped structure.

[0014] In a second aspect, the embodiments of the present application also provide an electric machine, comprising a machine shell, and the oil-cooled stator lamination is arranged in the machine shell.

[0015] In a third aspect, the embodiments of the present application also provide an electric drive system of an automobile, comprising the electric machine.

[0016] The beneficial effects of the present application are as follows: (1) The oil cooling structure area of the oil-cooled stator lamination sheet of the application comprises a first layer of oil cooling structure and a second layer of stress buffering structure, both of which are composed of uniformly distributed square holes and partitioning ribs, the partitioning ribs of the first layer of oil cooling structure are located in the circumferential middle of the square holes of the second layer of stress buffering structure, and the partitioning ribs of the second layer of stress buffering structure are located in the circumferential middle of the square holes of the first layer of oil cooling structure, when the interference stress between the outer cooperating shell and the outer diameter of the stator lamination sheet occurs, it will be dispersed from the partitioning ribs of the first layer of oil cooling structure to the two partitioning ribs on the left and right of the square holes of the second layer of stress buffering structure, which not only disperses the stress, but also blocks and absorbs the stress from being transmitted to the yoke part of the electromagnetic area, thereby reducing the stress loss of the electromagnetic area, improving the efficiency of the electric drive, and increasing the endurance of the CLTC working condition.

[0017] (2) The number a of the first square hole is 1-1.5 times the number b of the electromagnetic area slot, the circumferential uniform distribution number and size of the second square hole are consistent with those of the first square hole, the width d2 of the second partitioning rib is consistent with the width d1 of the first partitioning rib, the dislocation angle of the first layer of oil cooling structure and the second layer of stress buffering structure in the circumferential direction is , the relationship between the width d between the first layer of oil cooling structure and the second layer of stress buffering structure and the radial width n1 of the first square hole is d≥0.8 n1, through the above size relationship, the width d between the first layer of oil cooling structure and the second layer of stress buffering structure can effectively absorb the stress generated by the interference between the shell and the stator without transmitting it. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of the application form a part thereof, serve to provide further understanding of the application, and together with the specification explain the application, and do not constitute an improper limitation on the application.

[0019] Figure 1 is an isometric view of the oil-cooled stator lamination sheet according to one or more embodiments of the application; Figure 2 is a front view of the oil-cooled stator lamination sheet according to one or more embodiments of the application; Figure 3 is a size identification diagram of the oil-cooled stator lamination sheet according to one or more embodiments of the application; Figure 4 is a stress analysis diagram of a traditional single-layer oil cooling structure; Figure 5 is a stress analysis diagram of the oil cooling structure and the stress buffering structure according to one or more embodiments of the application; Figure 6 is another stress buffering structure diagram according to one or more embodiments of the application.

[0020] Wherein, 1, the first layer oil cooling structure, 2, the second layer stress buffer structure, 3, the electromagnetic area yoke part, 4, the electromagnetic area slot, 5, the electromagnetic area tooth; 11, the first partitioning rib, 12, the first square hole; 21, the second partitioning rib, 22, the second square hole. DETAILED DESCRIPTION

[0021] It should be noted that the following detailed description is exemplary and is intended to provide further description of the present application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. In the description of the application, the terms "first", "second", and the like are used only for descriptive purposes and are not to be construed as indicating or implying relative importance.

[0022] For the convenience of description, if "up", "down", "left", "right" appear in the present application, it only means consistent with the up, down, left, right direction of the drawing itself, and does not limit the structure, only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as a limitation on the present application.

[0023] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0024] Example 1: The existing oil-cooled stator cooling scheme is usually to open uniform square holes around the outer diameter of the stator core, but the stress generated by the interference between the stator core and the shell will be directly transmitted to the magnetic circuit area of the stator core, causing increased loss. Based on this, the present embodiment provides an oil-cooled stator lamination, which is provided with a double-layer oil cooling structure area to reduce loss from the interference stress between the shell and the stator core.

[0025] Figure 1 is an isometric view of an oil-cooled stator lamination provided by an embodiment of the present application, Figure 2 is a front view of an oil-cooled stator lamination provided by an embodiment of the present application, as an example, Figure 1 and Figure 2 As shown in the drawings, the oil-cooled stator lamination is in the shape of a circular ring, which is provided with a first layer oil cooling structure 1, a second layer stress buffer structure 2 and an electromagnetic area from outside to inside. When the outer shell and the outer diameter of the oil-cooled stator lamination produce an interference stress, the stress will be dispersed from the first layer oil cooling structure 1 to the second layer stress buffer structure 2, which not only disperses the stress, but also blocks and absorbs the stress from continuing to transmit to the electromagnetic area.

[0026] The first layer oil cooling structure 1 comprises a plurality of first partitioning ribs 11 and first square holes 12, and the second layer stress buffering structure 2 comprises a plurality of second partitioning ribs 21 and second square holes 22. Figure 1 and Figure 2 As shown in the figure, the first square holes 12 are uniformly distributed along the circumferential direction of the oil cooling stator lamination edge, and the first partitioning ribs 11 are arranged between adjacent first square holes 12; the second square holes 22 are arranged inside the first square holes 12 and are uniformly distributed along the circumferential direction of the oil cooling stator lamination, and the second partitioning ribs 21 are arranged between adjacent second square holes 22. The second square holes 22 and the first square holes 12 are arranged in a staggered manner, which can disperse the stress in different directions.

[0027] In the scheme provided by the embodiment of the present application, the first partitioning rib 11 corresponds to the middle position of the circumferential extension direction of the second square hole 22, and at the same time, the second partitioning rib 21 corresponds to the middle position of the circumferential extension direction of the first square hole 12. When the interference stress between the externally matched shell and the outer diameter of the oil cooling stator lamination occurs, the stress will be dispersed and transmitted from the first partitioning rib 11 to the circumferential left and right two second partitioning ribs 21 of the second square hole 22, which not only disperses the stress, but also blocks and absorbs the stress from being transmitted to the yoke part of the electromagnetic area, thereby reducing the stress loss of the electromagnetic area.

[0028] The electromagnetic area comprises an electromagnetic area yoke part 3, an electromagnetic area tooth 5 and an electromagnetic area slot 4. The electromagnetic area yoke part 3 is arranged inside the second layer stress buffering structure 2, the electromagnetic area tooth 5 is uniformly distributed along the inner circle of the oil cooling stator lamination, and the electromagnetic area slot 4 is arranged between adjacent electromagnetic area teeth 5.

[0029] Figure 3 The figure is a size identification diagram of the oil cooling stator lamination provided by the embodiment of the present application. As an example, as shown in the figure, Figure 3 the width between the first layer oil cooling structure 1 and the second layer stress buffering structure 2 is d, the radial width of the first square hole 12 is n1, the circumferential width of the first square hole 12 is m1, the number of the first square hole 12 is a, the width of the first partitioning rib 11 is d1, the width of the second partitioning rib 21 is d2, and the number of the electromagnetic area slot 4 is b.

[0030] In the scheme provided by the embodiment of the present application, the circumferential uniform distribution number of the first square hole 12 is determined by the width d1 of the first partitioning rib 11 and the circumferential width size m1 of the first square hole 12. The width d1 is determined by the stress size F generated by the interference between the shell and the stator. Since the first partitioning rib 11 is used to bear the stress generated by the interference between the shell and the stator, the width d1 cannot be too small. The circumferential width size m1 of the first square hole 12 is determined by the oil cooling flow demand and the outer diameter size D of the stator lamination. In this embodiment, m1 = c d1, c is a constant, and in this embodiment, the value of c is 3-4.

[0031] In the scheme provided by the embodiment of the application, the number a of the first square holes 12 is 1-1.5 times the number b of the electromagnetic area grooves 4, and a reasonable number of the first square holes 12 helps to balance the stress distribution inside the oil-cooled stator punching sheet, and can minimize the interference with the magnetic field on the premise of meeting the cooling requirement, so as to ensure that the motor has good electromagnetic performance.

[0032] The circumferential uniform number and size of the second square holes 22 are consistent with those of the first square holes 12, and the width d2 of the second partition rib 21 is consistent with the width d1 of the first partition rib 11, so that uniform stress transmission can be achieved.

[0033] As shown in Figure 3 , the misalignment angle of the first layer oil cooling structure 1 and the second layer stress buffering structure 2 in the circumferential direction is , and the misalignment arrangement mode of the first layer oil cooling structure 1 and the second layer stress buffering structure 2 makes the stress not directly concentrated and transmitted to the second layer stress buffering structure 2, thereby reducing local stress concentration.

[0034] The width d between the first layer oil cooling structure 1 and the second layer stress buffering structure 2 is used to bear and absorb the stress generated by the interference amount between the casing and the stator transmitted by the first partition rib 11, wherein d≥0.8 n1. The width d2 of the second partition rib 21 is used to bear and absorb the stress generated by the interference amount between the casing and the stator transmitted by the first partition rib 11 and then transmitted to the electromagnetic area yoke 3.

[0035] The size limitation in the embodiment makes the width d between the first layer oil cooling structure 1 and the second layer stress buffering structure 2 effectively absorb the stress generated by the interference amount between the casing and the stator transmitted by the first partition rib 11 without transmission.

[0036] Figure 4 is a stress analysis diagram of a traditional single-layer oil cooling structure, Figure 5 is a stress analysis diagram of the oil cooling structure and the stress buffering structure provided by the embodiment of the application, and by comparing Figure 4 and Figure 5 , it can be seen that the oil-cooled stator punching sheet structure of the embodiment can significantly reduce the stress transmitted to the electromagnetic area yoke 3, thereby reducing the iron loss and improving the electric drive efficiency.

[0037] It can be understood that in other embodiments, the second square hole 22 can also be in radial communication with the first square hole 12 to form a Z-shaped structure; Figure 6 is another stress buffering structure diagram, which also has the effect of stress dispersion.

[0038] Embodiment 2: The embodiment provides a motor, which comprises a shell, a stator assembly is arranged in the shell, the stator assembly comprises a stator winding and a motor stator, the motor stator is arranged outside the stator winding, and a rotor is arranged in the motor stator; wherein the motor stator comprises a plurality of oil-cooled stator sheets described in the embodiment 1.

[0039] Embodiment 3 The embodiment provides an automobile electric drive system, which comprises the motor described in the embodiment 2.

[0040] The above only provides preferred embodiments of the application and is not intended to limit the application. The application can have various changes and modifications for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. An oil-cooled stator lamination, characterized in that, It includes a first oil-cooling structure and a second stress-buffering structure arranged from the outside to the inside. The first oil-cooling structure includes a plurality of first square holes evenly distributed along the circumference, and a first partition rib is provided between adjacent first square holes. The second stress-buffering structure includes a plurality of second square holes evenly distributed along the circumference, and a second partition rib is provided between adjacent second square holes. The first partition bar corresponds to the middle position of the second square hole, and the second partition bar corresponds to the middle position of the first square hole. When external interference stress is generated, the first partition bar will distribute the stress to the second partition bars on both sides of the second square hole.

2. The oil-cooled stator lamination according to claim 1, characterized in that, The circumferential misalignment angle between the first oil-cooling structure and the second stress-buffering structure is... .

3. The oil-cooled stator lamination according to claim 1, characterized in that, The width between the first oil-cooling structure and the second stress-buffering structure is d, and the radial width of the first square hole is n1. Where d≥0.8 n1.

4. An oil-cooled stator lamination according to claim 1 or 3, characterized in that, The circumferential width of the first square hole is m1, where m1 = c d1, where d1 is the width of the first partition bar and c is a constant; The width of the second partition bar is d2, and d2 = d1.

5. The oil-cooled stator lamination according to claim 1, characterized in that, The inner side of the second layer stress buffer structure is provided with an electromagnetic region yoke and electromagnetic region teeth in sequence. The electromagnetic region teeth are evenly distributed along the circumference, and electromagnetic region grooves are provided between adjacent electromagnetic region teeth.

6. The oil-cooled stator lamination according to claim 5, characterized in that, The number of the first square holes is 1 to 1.5 times the number of electromagnetic region slots.

7. The oil-cooled stator lamination according to claim 6, characterized in that, The number and size of the second square holes are the same as those of the first square holes.

8. An oil-cooled stator lamination according to claim 1 or 7, characterized in that, The second square hole and the first square hole are radially independent of each other; Alternatively, the second square hole can be radially connected to the first square hole to form a Z-shaped structure.

9. An electric motor, characterized in that, Includes a housing, wherein the housing is provided with oil-cooled stator laminations as described in any one of claims 1-8.

10. An electric drive system for automobiles, characterized in that, Includes the motor as described in claim 9.

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