Stator for an electric machine, electric machine, motor vehicle, method for producing a stator
By designing the end disc on the motor stator to abut and support the card issuer, the problem of inaccurate pushing of the card issuer is solved, and the accuracy of the winding head geometry and the stability of the production process are achieved.
Patent Information
- Application Number
- CN202110741230.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Priority Date
- 2020-07-02
- Filing Date
- 2021-07-01
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2041-07-01
AI Technical Summary
When manufacturing the stator of the motor, the axial movement and inaccurate pushing of the card ejector element affect the dimensional accuracy of the winding head geometry and it is difficult to ensure a defined length of the leg end, resulting in inaccurate production.
A stator is designed with an end disc in the axial direction, and the card ejector element is attached to the end disc on the insertion side, and through the boundary and support of the end disc, ensuring the precise pushing and fixing of the card ejector element, forming a leg of a defined length The ends of the portion are for bending and connecting.
The precise push and firm fixation of the card issuer element is achieved, ensuring the accuracy of the geometry of the winding head, and avoiding damage through the support of the end disc, improving the accuracy and stability of the production process.
Smart Images
Figure CN113890236B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a stator for an electric machine, an electric machine, a motor vehicle and a method for producing a stator for an electric machine. Background Art
[0002] In the mass production of high-performance electric motors, stator windings consisting of so-called hairpins are usually used. Hairpins are generally U-shaped electrical conductors with two straight legs extending in parallel. These legs are connected to clips. The legs of the hairpin are pushed into the stator slots of the stator lamination stack in the axial direction, so that the clips are arranged on the axial end side of the stator lamination stack and the ends of the legs protrude on the other axial end side of the stator lamination stack. If necessary, the insulation of these ends is stripped, bent into a winding and connected (for example, welded).
[0003] In particular, when bending the winding, an axial displacement of the hairpin element may occur. This, as well as an inaccurate insertion of the hairpin element, may negatively affect the dimensional accuracy of the predefined winding head geometry. In addition, a defined length of the end of the leg is necessary for highly accurate production of the winding, in particular for accurate bending and connection of the end of the leg, which can only be ensured with difficulty by relative displacement between the hairpin element and the stator laminated core.
[0004] Stators for electric machines are already known from the prior art, which have end disks at the axial end sides of the stator core. Thus, document DE 10 2010 055 821 A1 discloses a metal end disk welded or brazed to the end sides of the stator core for mechanically stabilizing the winding head web. Summary of the invention
[0005] The object of the present invention is to provide a stator for an electric machine which does not have the above-mentioned disadvantages of the prior art but allows the hairpin elements to be pushed precisely into the stator laminate core during the production of the winding and to be securely fixed.
[0006] This object is achieved by a stator for an electric motor, the stator having a stator laminated core and a stator winding, wherein the stator winding has clip elements pushed into stator slots of the stator laminated core, wherein the clip elements are pushed into the stator slots on an insertion side of the stator laminated core and are bent on a bent side of the stator laminated core opposite to the insertion side in an axial direction and are electrically connected to form the stator winding, wherein the stator has an end disk, which is arranged on the insertion side in an axial direction between the stator laminated core and the clip elements, wherein the clip elements are arranged to abut against the end disk in an axial direction.
[0007] The stator according to the invention can be manufactured very precisely. The insertion of the clip element during the production process is mechanically limited by the clip element abutting against the end disc in the axial direction. This limitation results in a defined spacing between the clip part of the clip element and the stator laminated core on the insertion side, and thus a defined winding head geometry on the insertion side. In addition, a leg end of a defined length is obtained for bending. In addition, the abutment against the end disc allows the clip element to be better fixed during manufacturing, for example by a constant force, which acts on the clip part in the axial direction during bending and presses the clip element against the end disc.
[0008] In the sense of the present invention, an axial direction is a direction along the stator axis. In the sense of the present invention, a radial direction is perpendicular to the axial direction and points outwards from the stator axis.
[0009] Advantageous embodiments and improvements of the invention can be gathered from the description of preferred embodiments and with reference to the drawings.
[0010] According to a preferred embodiment of the present invention, these hairpin elements are pushed into these stator slots with two straight legs respectively, wherein the legs of one hairpin element are connected to the clip portions of the hairpin element arranged at a certain angle to these legs, wherein the end disc is designed to partially follow the contour of the clip portions of these hairpin elements in the axial direction. In the sense of the present invention, following the contour means abutting along the contour. That is, the end disc abuts against the clip portion at the point where it follows the contour of the clip portion. Thus, the hairpin elements are supported at an angle in an advantageous manner, in particular, also by a directional component orthogonal to the axial direction. Thus, the firm fixation of the hairpin components and the limitation of the pushing-in path are advantageously improved.
[0011] According to another preferred embodiment of the present invention, a first leg of a first clip element is arranged in a first stator slot, the first clip element has a first clip portion arranged extending in the circumferential direction of the stator, and a second leg of a second clip element is arranged in a second stator slot adjacent to the first stator slot in the circumferential direction, the second clip element has a second clip portion arranged extending in the opposite direction to the circumferential direction, wherein the first clip portion and the second clip portion intersect each other at a cross spacing from the stator lamination stack in the axial direction, wherein the end disc is designed to follow the contour of the first clip portion and the contour of the second clip portion in the axial direction until the cross spacing. In other words, the clip portion spans the space between the stator lamination stack and the clip portion, and the end disc is arranged in the space so that the end disc partially follows the contour of the clip portion. Therefore, the existing structural space is optimally utilized and the hairpin element can be firmly supported on the end disc.
[0012] According to another preferred embodiment of the present invention, the clip parts have a curved first transition area arranged on the legs, a straight middle area arranged on the first transition area, and a curved second transition area arranged between the middle areas, wherein the end disc is designed to at least partially follow the contour of the first transition areas in the axial direction, but not to follow the contour of the middle areas. Thus, the formation of sharp corners and edges on the end disc and possible damage when the hairpin element is attached to the end disc (for example in the insulating area) are avoided in an advantageous manner.
[0013] According to another preferred embodiment of the present invention, the first clip part and the second clip part are arranged to intersect each other in the first transition area of the first clip part and the first transition area of the second clip part. In other words, the clip part spans a dome that is filled by the end plate. This achieves optimal support for the hairpin element.
[0014] According to another preferred embodiment of the present invention, the end disc has an opening extending in the axial direction, through which the hairpin elements are pushed into the stator slots. As a result, the legs of the hairpin elements can also be supported in the radial and circumferential directions when pushed in in an advantageous manner. This can avoid damage to the stator lamination stack. It is also conceivable that the end disc abuts against the hairpin elements in the region of the opening in a fluid-tight manner. This can seal the stator slots relative to the winding head space.
[0015] For this purpose, it is preferably provided that only one hairpin element is inserted into each opening.
[0016] However, it is conceivable that all hairpin elements extending together in a stator slot are inserted into each opening, ie the openings receive legs of hairpin elements arranged together in a stator slot.
[0017] According to another preferred embodiment of the present invention, the end disc is non-conductive. This advantageously enables the stator lamination stack to be electrically insulated in the direction of the winding head space. It is conceivable that the end disc has an insulating layer. However, it is also conceivable that the end disc is made of an insulating material.
[0018] According to another preferred embodiment of the present invention, the end disc is elastic. This also advantageously prevents damage to the hairpin element during the manufacture of the stator. It is also conceivable that vibrations are reduced by the elastic end disc during the operation of the stator. For example, it is conceivable that the end disc is made of a rubber material. The elastic design of the end disc is particularly advantageous in that when the hairpin element is pushed in, the force increases with the increase of the deformation of the end disc after contact with the end disc. As a result, a defined push-in can be achieved by force measurement.
[0019] In order to achieve the object stated at the outset, a further subject matter of the invention is an electric machine having a stator according to the invention.
[0020] A further subject matter of the invention for achieving the object stated at the outset is a motor vehicle having an electric machine according to the invention.
[0021] Another subject of the invention for achieving the object stated at the outset is a method for producing a stator according to the invention, wherein the clip elements are pushed into the stator lamination stack in the axial direction, wherein the insertion of the clip elements in the axial direction is limited by the clip elements contacting the end disk. As a result, the distance of the insertion of the clip elements is advantageously determined and the clip elements are fixed.
[0022] According to another preferred embodiment of the invention, it is proposed that the force required for pushing in the clip elements is measured, wherein the pushing in is terminated when the maximum force is reached. Thus, a very accurately defined position of the clip elements is achieved after the pushing in.
[0023] All details, features and advantages disclosed above in conjunction with the stator according to the invention also relate to the electric machine according to the invention, the motor vehicle according to the invention and the method according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Further details, features and advantages of the invention will be apparent from the drawings and the following description of preferred embodiments with the aid of the drawings. These drawings merely illustrate exemplary embodiments of the invention and do not restrict the inventive concept.
[0025] FIG. 1( a ), FIG. 1( b ) and FIG. 1( c ) schematically illustrate a hairpin element or stator according to an exemplary embodiment of the present invention.
[0026] Figure 2 Details of a stator according to an exemplary embodiment of the invention are schematically shown.
[0027] Figure 3 A motor vehicle according to an exemplary embodiment of the invention is schematically illustrated. DETAILED DESCRIPTION
[0028] FIG1( a) schematically shows a hairpin element 5 used in a stator. The hairpin element 5 is an electrical conductor and is typically insulated (except for the end 5.3 of the hairpin element 5). It is named after its hairpin-like shape, which has two straight legs 5.1 arranged parallel to each other, which are connected by a clip 5.2. The clip 5.2 has a curved first transition area 5.2.1 on the legs 5.1. A straight intermediate area 5.2.2 is arranged between the first transition area 5.2.1 and the curved, centrally arranged second transition area 5.2.3.
[0029] FIG. 1( b ) schematically shows a stator 1 according to an exemplary embodiment of the present invention during production using a method according to an exemplary embodiment of the present invention. The hairpin element 5 is pushed into the stator slot 4 of the stator laminated core 2 in the axial direction A. Here, the hairpin element 5 is pushed in on the insertion side 2.1 so that the end 5.3 of the hairpin element 5 protrudes from the stator laminated core 2 on the bent side 2.2 opposite the insertion side 2.1 in the axial direction A. To ensure the correct fit of the hairpin element 5, an end disk is provided on the insertion side 2.1 (not visible here for perspective reasons, see Figure 2 ), the hairpin element 5 is in abutment against the end disc in the axial direction A.
[0030] Furthermore, for better orientation, a radial direction R and a circumferential direction U can be seen from this figure.
[0031] FIG. 1( c ) schematically shows the stator 1 of FIG. 1( b ) after the following manufacturing steps. The end 5.3 of the hairpin 5 inserted into the stator lamination stack 2 from the insertion side 2.1 is bent on the bending side 2.2 and connected (e.g. welded, brazed or pressed) to form the stator winding 3. During the bending process, the hairpin 5 is held in place by the end disc. Movement in the axial direction is prevented by contact with the end disc, and movement in the opposite direction to the axial direction is prevented by an insertion tool (not shown) exerting a force on the hairpin 5 in the axial direction.
[0032] Figure 2 A detail of a stator 1 according to an exemplary embodiment of the invention is schematically illustrated. Hairpin elements 5 can be seen, which protrude at the insertion side 2 . 1 of the stator core 2 .
[0033] In the axial direction A, the end disc 6 is arranged between the hairpin element 5 and the stator laminated core 2. Preferably, the end disc 6 is electrically insulating and elastic. Here, the end disc 6 is shaped so that it can optimally support the hairpin element 5 in the axial direction A.
[0034] This can be described with two exemplary hairpin elements 5 ′, 5 ″:
[0035] The first hairpin element 5' is pushed into the first stator slot 4.1 of the stator lamination stack 2 by means of the first leg (not visible). Here, the first stator slot 4.1 is also not visible, but its position is marked by corresponding markings. The first clip part 5.2' of the first hairpin element 5' extends in the circumferential direction U.
[0036] The second hairpin element 5" is pushed with the aid of a second leg (not visible) into a second stator slot 4.2 of the stator laminated core 2 adjacent to the first stator slot 4.1 in the circumferential direction U. Here, the second stator slot 4.2 is also not visible. However, its position is indicated by corresponding markings. The second clip portion 5.2" of the second hairpin element 5" extends opposite to the circumferential direction U.
[0037] The first transition region 5.2.1 of the first clamping part 5.2' and the second transition region 5.2.1 of the second clamping part 5.2" intersect at an intersection distance K from the stator laminated core 2. The end disc 6 follows the contour of the clamping parts 5.2', 5.2" until the intersection distance K and abuts against the clamping parts 5.2', 5.2". This makes it possible to achieve a round shape of the end disc 6 and optimize the abutment surface of the hairpin element 5 on the end disc 6.
[0038] The end disk 6 limits the possible path when the hairpin 5 is pushed in in the axial direction A. By measuring the force of the push-in, it can be determined that the hairpin 5 is in contact with the end disk 6. If the force reaches a maximum force, the push-in can be stopped and a defined winding head geometry is achieved.
[0039] Figure 3 A motor vehicle 200 according to an exemplary embodiment of the present invention is schematically illustrated, which has an electric machine 100 according to an exemplary embodiment of the present invention.
Claims
1. A stator (1) for an electric machine (100), the stator having a stator core (2) and a stator winding (3), wherein the stator winding (3) has clip elements (5) which are inserted into stator slots (4) of the stator core (2), wherein the clip elements (5) are inserted into the stator slots (4) on an insertion side (2.1) of the stator core (2) and are located opposite the insertion side (2.1) in the axial direction (A) of the stator core (2). The stator winding (3) is bent on a bent side (2.2) disposed thereon and is electrically connected to form the stator winding (3), wherein the stator (1) has an end disc (6) which is arranged on the insertion side (2.1) between the stator laminated core (2) and the hairpin elements (5) in an axial direction (A), wherein the end disc (6) is not part of the stator laminated core (2) and is non-conductive, wherein the hairpin elements (5) are arranged to abut against the end disc (6) in the axial direction (A), wherein: The end plate (6) has a first axial end facing the stator lamination stack (2) and a second axial end away from the first axial end, the first axial end being configured to follow the surface structure of the stator lamination stack (2), and the second axial end being rounded and configured to completely follow and abut against a portion of the inner contour of each of the hairpin elements (5) when the hairpin elements (5) abut against the end plate (6).
2. A stator (1) according to claim 1, wherein the hairpin elements (5) are pushed into the stator slots (4) with two straight legs (5.1), and the legs (5.1) of one hairpin element (5) are connected to a clip part (5.2) of the hairpin element (5) arranged at a certain angle to the legs (5.1).
3. The stator (1) according to claim 2, wherein a first leg of a first hairpin element (5') is arranged in a first stator slot (4.1), the first hairpin element having a first clip portion (5.2') extending in a circumferential direction (U) of the stator (1), and a second leg of a second hairpin element (5") is arranged in a second stator slot (4.2) adjacent to the first stator slot (4.1) in the circumferential direction (U), the second hairpin element having a first clip portion (5.2') extending in a circumferential direction (U) of the stator (1). A second clip portion (5.2") is arranged to extend in the opposite direction to the circumferential direction (U), wherein the first clip portion (5.2') and the second clip portion (5.2") intersect each other at a crossing distance (K) from the stator lamination stack (2) in the axial direction (A), wherein the end disc (6) is designed to follow the contour of the first clip portion (5.2') and the contour of the second clip portion (5.2") in the axial direction (A) up to the crossing distance (K).
4. A stator (1) according to claim 3, wherein the clip portions (5.2) have a curved first transition region (5.2.1) arranged on the legs (5.1) and a straight intermediate region (5.2.2) arranged on the first transition regions (5.2.1) and a curved second transition region (5.2.3) arranged between the intermediate regions (5.2.2), wherein the end disc (6) is designed to at least partially follow the contour of the first transition regions (5.2.1) in the axial direction (A), and is not designed to follow the contour of the intermediate regions (5.2.2).
5. The stator (1) according to claim 4, wherein the first clip portion (5.2') and the second clip portion (5.2") are arranged to intersect each other in the region of a first transition region (5.2.1) of the first clip portion (5.2') and a first transition region (5.2.1) of the second clip portion (5.2").
6. The stator (1) according to one of claims 1 to 5, wherein the end disc (6) has openings which are arranged extending in the axial direction (A) and through which the hairpin elements (5) are pushed into the stator slots (4).
7. The stator (1) according to claim 6, wherein only one hairpin element (5) is pushed into each opening.
8. The stator (1) according to claim 6, wherein all hairpin elements (5) extending together in a stator slot (4) are pushed into each opening.
9. The stator (1) according to one of claims 1 to 5, 7 and 8, wherein the end disk (6) is elastic.
10. An electric machine (100) comprising a stator (1) according to any one of claims 1 to 9.
11. A motor vehicle (200) having an electric machine (100) according to claim 10.
12. A method for manufacturing a stator (1) according to one of claims 1 to 9, wherein the clip elements (5) are pushed into the stator laminated core (2) in an axial direction (A), wherein the pushing in of the clip elements in the axial direction is limited by the clip elements (5) contacting the end disc (6).
13. The method according to claim 12, wherein the force required for pushing in the hairpin elements (5) is measured, wherein the pushing in is terminated when a maximum force is reached.