Method for producing stator winding of stator, electric machine and motor vehicle

Abstract

The invention relates to a method for producing a stator winding (1) for driving a stator (2) of an electric machine (3) of a motor vehicle (4). First, a stator base body (5) having a base body longitudinal axis (6) and a plurality of stator slots (7) is provided. Hairpins (8) are arranged in the stator slots (7). A hairpin end region (9) protruding from a base body end face of the stator base body (5) is twisted from an initial position (A) to a final position (E) using a twisting tool (11) such that the free hairpin ends (10) are arranged obliquely to the base body longitudinal axis (6) and a majority of the free hairpin ends (10) converge together to form an end pair (12). Finally, the free hairpin ends (10) of the end pair (12) are connected to each other. The invention also relates to an electric motor (3) for driving a motor vehicle (4) and to a motor vehicle (4) having an electric drive system (16).

Description

Technical Field

[0001] This invention relates to a method for manufacturing stator windings for a stator of an electric motor used to drive a motor vehicle. The invention also relates to an electric motor for driving a motor vehicle and a motor vehicle having such an electric motor for driving the motor vehicle. Background Technology

[0002] Electric motors for driving motor vehicles are known, having a stator and a rotor arranged coaxially with and rotatably mounted to the stator. The stator has stator windings made of winding wires.

[0003] One known type of winding is called a "hairpin winding". A hairpin winding has multiple so-called "hairpins" arranged in stator recesses in the stator matrix of the stator. In order to produce a continuous winding, the free hairpin ends are twisted in the circumferential direction, cut to a certain length by a cutting process, and in each case, electrically and mechanically coupled to each other in pairs, for example by welding, brazing, etc.

[0004] The hairpin is either a rod-shaped I-shaped clip or a U-shaped clip with two parallel legs and a common bending area. The advantage of the U-shaped clip is that after the hairpin is placed in the stator matrix, the winding head is already formed by the bending area, thus eliminating the need for subsequent twisting and engagement processes on this side of the stator.

[0005] Various methods for manufacturing stator winding heads are known from documents KR 10 202 2 0 160 175 A, KR 10 202 3 0 005 639 A, and DE 10 202 2130 168 A1, in which the free ends of multiple hairpins are first brought together in pairs and then twisted in opposite directions along the circumference of the stator. The tool used for this task has multiple concentric rings designed to rotate relative to each other. After twisting, the free ends protrude axially from the stator and can be separated from the stator during a subsequent cutting process.

[0006] Known methods for manufacturing stator winding heads have the following drawbacks: in addition to bending and welding processes, a cutting process is performed to minimize the installation space required for the winding head. These cutting processes require cutting tools designed for this purpose, making them particularly time-consuming and costly. Furthermore, the cutting process increases material costs because the hairpins must be made longer to be cut. This further increases the manufacturing cost of the stator windings. Summary of the Invention

[0007] Therefore, the object of the present invention is to eliminate, or at least partially eliminate, the aforementioned disadvantages in the stator windings of the stator of an electric motor for driving a motor vehicle. Specifically, the object of the present invention is to create a method for manufacturing a stator winding for a stator of an electric motor for driving a motor vehicle, an electric motor for driving a motor vehicle, and a motor vehicle having an electric motor for driving a motor vehicle, which has particularly small installation space requirements in a simple and cost-effective manner.

[0008] The aforementioned task is achieved through the patent claims. Therefore, this task is accomplished by a method for manufacturing a stator winding for a motor for driving a motor vehicle, having the features of independent claim 1; by a motor for driving a motor vehicle, having the features of independent claim 9; and by a motor vehicle having a motor for driving a motor vehicle, having the features of independent claim 10. Further features and details of the invention become apparent from the dependent claims, the specification, and the drawings. The features and details described in conjunction with the method according to the invention also apply to the motor according to the invention and the motor vehicle according to the invention, and vice versa, so that reference, or always possible, can be made to the disclosures regarding various aspects of the invention.

[0009] According to a first aspect of the invention, this task is achieved by a method for manufacturing stator windings for a stator of an electric motor used to drive a motor vehicle. The method comprises:

[0010] - Provides a stator matrix with a longitudinal axis and multiple stator slots.

[0011] - Arrange the hairpin in the stator slot such that the hairpin end area protrudes from the stator slot as a free hairpin end on the base end face of the stator substrate.

[0012] - Use a twisting tool to twist the hairpin end area from the initial position to the final position, so that the hairpins are arranged at an angle relative to the longitudinal axis of the base at the free hairpin ends, and the hairpins at the free hairpin ends converge to form end pairs, and

[0013] -Connection end pair.

[0014] The provided stator substrate preferably has a stator lamination assembly consisting of multiple stator lamination disks stacked adjacent to each other coaxially with the longitudinal axis of the substrate, for example, made of electrical steel. The stator lamination disks are preferably coated with an electrical insulating layer, such as varnish, to prevent current from flowing through the stator substrate. Stator slots are formed in the stator substrate. The slot width extends circumferentially in the stator substrate, the slot depth extends radially from the longitudinal axis of the substrate, and the slot length extends parallel to the longitudinal axis of the substrate through the entire stator substrate, such that the stator slots are constructed open at the end faces of the stator substrate. In the radial direction, the stator slots are defined by the stator substrate. The stator slots are preferably arranged in a uniformly distributed circumferential direction.

[0015] Hair clips are provided as U-shaped clips or I-shaped clips, wherein twisting and electrical connection are performed on one side of the stator base in the case of U-shaped clips, and preferably on both sides of the stator base in the case of I-shaped clips. I-shaped clips substantially correspond to the legs of U-shaped clips. For simplicity, the legs of U-shaped clips are referred to as hair clips within the scope of this invention. Hair clips preferably have a rectangular cross-section. Hair clips can be arranged, for example, by inserting them into stator slots. For example, hair clips can be held aligned on retaining devices and simultaneously inserted into stator slots. The arrangement of hair clips in the stator slots is such that the hair clip end region of the hair clip protrudes from the stator slot, and the free hair clip end is located on one base end face of the stator base. For I-shaped clips, the hair clips are arranged in the stator slots such that the hair clip end region of the hair clip protrudes from the stator slot, and free hair clip ends are located on both base end faces of the stator base. Hair clips are arranged in the stator slots as multiple hairpinlagens formed adjacent to each other in the radial direction. According to the invention, for example, four, six, eight, or ten hairpin layers can be provided. The hairpins are preferably made of copper and more preferably have an electrically insulating layer or coating.

[0016] The hairpin end region is understood to refer to the hairpin area including the free hairpin end and the hairpin portion extending from the free hairpin end. The free end of the hairpin restricts the longitudinal range of the hairpin in one direction. For example, a free hairpin end can be created when a winding wire is cut to a certain length to produce a hairpin. In addition, the free end of the hairpin can also have a shape different from a straight-cut surface, such as a chamfer, rounding, etc.

[0017] Before twisting the hairpin end region, the hairpin end region is preferably widened, by which the hairpin end region bends upward in the radial direction. For twisting, the twisting tool is preferably brought to and engaged with the free hairpin end. Preferably, the twisting tool engages with the free hairpin end of each hairpin layer. Twisting is preferably performed in such a way that the free hairpin ends of adjacent hairpin layers are twisted along opposite circumferential directions of the stator matrix. According to the invention, twisting is performed with the hairpins arranged in the final position. In the final position, the hairpins are arranged at the free ends of the hairpins at an angle to the longitudinal axis of the matrix. Furthermore, the hairpins converge into end pairs at the free ends. Preferably, hairpins intended to connect the stator windings to, for example, power electronics are excluded. According to the invention, all free hairpin ends can also converge together to form end pairs. For eight hairpin layers, for most stator slots, for example, four end pairs are arranged adjacent to each other in the radial direction; for six hairpin layers, for example, three end pairs are arranged. Preferably, the number of hairpin layers in each stator slot is twice the number of end pairs arranged adjacent to each other in the radial direction. Widening and / or twisting are preferably performed as cold forming, preferably at room temperature.

[0018] Finally, the free hairpin ends of the end pair are connected to each other in pairs, for example, by welding or brazing. This ensures that the free hairpin ends of the end pair are electrically coupled to each other. Therefore, multiphase stator windings can be manufactured.

[0019] The method for manufacturing a stator winding for a motor for driving a motor vehicle according to the present invention has the following advantages over conventional methods: the stator winding, having a winding head with a particularly small extension in the axial direction, can be manufactured using simple equipment and in a cost-effective manner. Therefore, the stator requires less space in the axial direction compared to conventional stators. By eliminating the separation process after torsion, the manufacturing of the stator winding is simplified compared to conventional processes and can be carried out in a more time-, material-, and cost-efficient manner.

[0020] According to a preferred improvement of the invention, in a method for manufacturing the winding head of a stator for a motor for driving a motor vehicle, it can be specified that the same twisting tool is used to twist the hairpin end region from an initial position to a final position. For this purpose, the twisting tool preferably has multiple receiving areas for each hairpin, these receiving areas being designed differently. The receiving areas are preferably designed such that the hairpin end region is successively guided by different receiving areas during the twisting process. This has the advantages of using simple components and ensuring particularly efficient manufacturing of the stator winding in a cost-effective manner. By using only one twisting tool for twisting, non-manufacturing time, such as removing the first twisting tool and introducing another, can be avoided, thereby reducing the manufacturing time of the stator winding.

[0021] According to the invention, the twisting of the hairpin end region from the initial position to the final position is preferably performed in a multi-stage process through an intermediate position formed between the initial and final positions. The twisting is preferably performed in a two-stage process. During the second twist, the twisting tool preferably moves relative to the stator substrate in the axial direction to produce a winding head that is as flat as possible. According to the invention, multiple intermediate positions can also be provided, so that the twisting can also be performed in a three-stage, four-stage, or multi-stage process. An intermediate position is understood to refer, for example, to a state during the formation of the hairpin end region, where the formation direction of the hairpin end region changes, for example, abruptly. Thus, for example, a first region of the hairpin end region can be formed between the initial and intermediate positions, and a second region of the hairpin end region, different from the first region, can be formed between the intermediate and final positions. This has the advantages of using simple equipment and ensuring particularly efficient manufacturing of the stator winding in a cost-effective manner. Multi-stage twisting also reduces the manufacturing time of the stator winding.

[0022] More preferably, the hairpin end region is first twisted from an initial position to an intermediate position using a twisting tool, then the twisting tool is moved to the hairpin end region, and finally the hairpin end region is twisted from the intermediate position to the final position. Therefore, the twisting tool preferably has a first receiving area for each hairpin end region and a second receiving area designed differently from the first receiving area. The first receiving area preferably forms a common receiving portion with the second receiving area. Preferably, the first receiving area is arranged adjacent to the second receiving area, particularly immediately adjacent to the second receiving area. Preferably, the first receiving area has a smaller dimension in the circumferential direction than the second receiving area. The first twist is preferably performed in such a way that the hairpin end region engages with the first receiving area. The hairpin end region is preferably arranged in the first receiving area. Then the twisting tool rotates in the circumferential direction. During the first twist, the second receiving area preferably does not engage with the hairpin end region. After reaching the intermediate position, the twisting tool moves to the hairpin end region such that the hairpin end region engages with the second receiving area. For example, this can also be done automatically by continuing the movement of the twisting tool according to the first twist. The hairpin end region is now preferably arranged in the second receiving area. Then the twisting tool rotates in the circumferential direction, preferably in the same direction as the first twist. During the second twist, the first receiving area preferably does not engage with the hairpin end area. The first receiving area differs from the second receiving area in that different torsional deformations are performed on the hairpin end area by the first and second twists. After reaching the final position, the twisting tool is removed from the hairpin end area. This has the advantages of using a simple device and ensuring particularly efficient manufacturing of the stator winding in a cost-effective manner. Multi-stage twisting can also reduce the manufacturing time of the stator winding.

[0023] In a particularly preferred embodiment of the invention, the transfer of the torsion tool can be specified in a method such that the torsion tool has a greater distance from the stator base after the transfer than before. In other words, during the transfer, the torsion tool preferably moves axially away from the stator base. Preferably, the hairpin end region is arranged in a first receiving region of the torsion tool before the axial movement. A region of the hairpin end region arranged closer to the stator base is arranged in a second receiving region, in which state preferably there is no contact generated by contact between the second receiving region and the hairpin end region. Due to the axial movement, the hairpin end region slides out of the first receiving region, such that the free hairpin end is now arranged in the second receiving region. By further rotating the torsion tool in the circumferential direction, the second receiving region is pressed against the free end of the hairpin, thereby causing a second torsion. This has the advantages of using a simple device and ensuring particularly efficient manufacturing of the stator winding in a cost-effective manner. Multi-stage stranding can also reduce the manufacturing time of the stator winding.

[0024] The twisting is preferably performed in such a manner that the free hairpin end rolls on the twisting tool between the final and intermediate positions. For this purpose, the free hairpin end preferably has a rolling profile, such as rounding, which facilitates the rolling of the hairpin on the twisting tool and prevents the hairpin from getting stuck or jittering on the twisting tool during the second twist. To prevent the hairpin from slipping off the twisting tool, the twisting tool preferably moves relative to the stator base in the axial direction during rolling. This has the advantages of using a simple device and ensuring particularly efficient manufacturing of the stator winding in a cost-effective manner. Rolling the hairpin on the twisting tool also creates a particularly flat winding head.

[0025] According to a preferred embodiment of the invention, the torsion is performed in such a way that each of the hairpin end regions has a first curved region near the stator base and a second curved region away from the stator base, wherein the first curvature of the first curved region is greater than the second curvature of the second curved region. The curved region is understood to refer to the area of ​​the hairpin that bends in one direction. Preferably, the first and / or second curved regions are designed as bends or rounded. The hairpin, initially exposed from the stator slot in the axial direction, has a first curved region, which may have an angle, for example, between 100° and 140°. Due to the first curved region, the hairpin bends in the circumferential direction, thus having extension components in both the axial and circumferential directions. The hairpin preferably does not deform between the first and second curved regions, such that the hairpin is straight in this intermediate region. Due to the second curved region, the hairpin bends slightly backward in the axial direction. The angle of the second curved region is greater than the angle of the first curved region. Therefore, the second curved region preferably deforms less than the first curved region. For example, the angle of the second curved region is between 120° and 170°. Therefore, after the second bending region, the hairpin has a smaller extension component in the circumferential direction and a larger extension component in the axial direction than the intermediate region. Preferably, the method is performed in such a manner that the second bending region is first fully or at least substantially generated, and the first bending region is only partially generated. Then the first bending region is completed. This has the advantages of using simple equipment and ensuring particularly efficient manufacturing of the stator winding in a cost-effective manner. By forming the bending region, a particularly flat winding head can be manufactured.

[0026] The twisting is particularly preferably performed in such a manner that the free hairpin ends of the end pair are arranged at an angle between 50° and 150° to each other. This means that the free hairpin ends point in opposite circumferential directions and the same axial direction, and thus such an angle is formed between the hairpin end regions directly adjacent to the free hairpin ends. This angle is particularly preferably between 80° and 120°, for example, 100°. This has the advantages of using simple equipment and ensuring particularly efficient manufacturing of the stator winding in a cost-effective manner. By producing such an angle, a particularly flat winding head can be manufactured.

[0027] According to a second aspect of the invention, this task is accomplished by an electric motor for driving a motor vehicle. The motor has a stator with stator windings and a rotor rotatably supported relative to the stator. According to the invention, the stator windings are manufactured by a method according to the invention.

[0028] The electric motor for driving a motor vehicle according to the invention has all the advantages already described with respect to the method for manufacturing a stator winding for a motor for driving a motor vehicle according to the first aspect of the invention. Therefore, the advantage of the motor according to the invention over conventional motors lies in the use of simple equipment and the cost-effective provision of a stator winding having a winding head with a particularly small extension in the axial direction. Thus, the stator requires less space in the axial direction compared to conventional stators. By eliminating the separation process after torsion, the manufacturing of the stator winding is simplified and is more time-, material-, and cost-effective compared to conventional processes.

[0029] According to a third aspect of the invention, this task is accomplished by a motor vehicle. The motor vehicle has an electric drive system. According to the invention, the electric drive system for driving the motor vehicle has a motor according to the invention.

[0030] The motor vehicle according to the invention possesses all the advantages already described for the method of manufacturing a stator winding for a motor for driving a motor according to the first aspect of the invention and for a motor for driving a motor according to the second aspect of the invention. Therefore, the advantage of the motor vehicle according to the invention over conventional motor vehicles lies in the use of simple equipment and the cost-effective provision of a stator winding having a winding head with a particularly small extension in the axial direction. Thus, the stator requires less space in the axial direction compared to conventional stators. By eliminating the separation process after torsion, the manufacturing of the stator winding is simplified and is more time-, material-, and cost-effective compared to conventional processes. Attached Figure Description

[0031] The following description, with reference to the accompanying drawings, explains in more detail the electric motor according to the invention, the motor vehicle according to the invention, and the method for manufacturing a stator winding for an electric motor for driving a motor vehicle according to the invention. The drawings schematically show:

[0032] Figure 1 A perspective view of a stator according to the prior art is shown.

[0033] Figure 2 The sectional view shows a first state when performing a preferred embodiment of the method according to the invention.

[0034] Figure 3 A cross-sectional view showing a second state in which the preferred embodiment of the method according to the invention is implemented.

[0035] Figure 4 A cross-sectional view showing a third state in which the method according to the invention is implemented, in a preferred embodiment.

[0036] Figure 5 The fourth state is shown in the cross-sectional view when a preferred embodiment of the method according to the invention is performed.

[0037] Figure 6 A cross-sectional view showing a fifth state in which the method according to the invention is implemented, in a preferred embodiment.

[0038] Figure 7 An exploded view of the motor according to a preferred embodiment of the present invention is shown.

[0039] Figure 8 A side view showing a preferred embodiment of a motor vehicle according to the present invention, and

[0040] Figure 9 A preferred embodiment of the method according to the invention is shown in the flowchart. Detailed Implementation

[0041] exist Figures 1 to 9 In this diagram, components with the same function and operating mode are all provided with the same reference numerals.

[0042] exist Figure 1The stator 2 according to the prior art is schematically shown in perspective view. The stator 2 has a stator base 5 extending along and around the longitudinal axis 6 of the base. A plurality of stator slots 7 are formed in the stator base 5. In the stator slots 7, a plurality of hairpins 8 are arranged radially in the plurality of slot positions. The hairpin end regions 9 of the hairpins 8 with free hairpin ends 10 protrude axially from the stator slots 7 and are twisted in such a way that the hairpin end regions 9 are arranged on the free hairpin ends 10 parallel to the longitudinal axis 6 of the base. The hairpin end regions 9 are combined into end pairs 12 and connected to each other in pairs. Thus, the stator winding 1 is formed by the hairpins 8. This stator 2 has a particularly large dimension in the axial direction.

[0043] Figure 2 A first state is schematically shown in cross-section when performing a preferred embodiment of the method according to the invention. The first state is initial position A. In initial position A, the hairpin 8 is arranged in the stator slot 7 of the stator base 5 such that the hairpin end region 9 of the hairpin 8 protrudes axially from the stator slot 7. A portion of the hairpin end region 9, having the free hairpin end 10 of the hairpin 8, is arranged in a first receiving portion 17 of the torsion tool 11. A second receiving portion 18 of the torsion tool 11 is arranged between the first receiving portion 17 and the stator base 5, and this second receiving portion does not function in initial position A. During the subsequent torsion process, the torsion tool 11 rotates circumferentially along the stator base 5, causing plastic deformation of the hairpin end region 9.

[0044] exist Figure 3 The diagram schematically illustrates a second state when performing a preferred embodiment of the method according to the invention in cross-section. In the second state, the hairpin end region 9 is in the intermediate position Z. In the intermediate position Z, the hairpin 8 continues to be oriented axially at the free hairpin end 10, while the region of the hairpin 8 arranged between the torsion tool 11 and the stator base 5 is oriented inclined to the longitudinal axis 6 of the base. In the second state, the first torsion is completed and the free hairpin end 10 continues to be arranged within the first receiving portion 17, allowing the torsion tool 11 to move.

[0045] Figure 4 A cross-sectional view schematically illustrates the third state when performing a preferred embodiment of the method according to the invention. The third state occurs after the first torsion during the movement of the torsion tool 11. Compared to the second state, the torsion tool 11 moves axially away from the stator base 5, such that the free hairpin end 10 is now arranged within the second receiving portion 18.

[0046] exist Figure 5The diagram schematically illustrates the fourth state when performing a preferred embodiment of the method according to the invention in cross-section. The fifth state is achieved by rotating the torsion tool 11 circumferentially, such that the wall of the second receiving portion 18 contacts the hairpin 8 at the free hairpin end 10. Now, in the second torsion, the movement of the torsion tool 11 can be performed with a component of movement in the axial direction, such that the hairpin end region 9 bends axially toward the stator base 5.

[0047] Figure 6 A cross-sectional view schematically illustrates the fifth state when performing a preferred embodiment of the method according to the invention. In the fifth state, the hairpin 8 is arranged in the final position E. In the final position E, the hairpin 8 has a first curved region 13 located directly at the end of the stator slot 7 and a second curved region 14 near the free hairpin end 10, the curved direction of which is opposite to that of the first curved region 13. The first curved region 13 has a larger curved angle than the second curved region 14. Therefore, the hairpin 8 has an orientation inclined relative to the axial direction between the second curved region 14 and the free hairpin end 10. The twisting tool 11 can then be removed from the hairpin 8, and the end pair 12 of the hairpin 8 (see...) Figure 7 They can be connected to each other, for example, by welding, brazing, etc. A stator 2 having a stator winding 1 according to the invention (see...) Figure 7 It has a much smaller dimension in the axial direction than the stator 2 according to the prior art.

[0048] exist Figure 7 The motor 3 according to a preferred embodiment of the present invention is shown schematically in an exploded view. The motor 3 has a stator 2 with a stator winding 1 according to the present invention. The stator winding 1 is formed by hairpins 8 arranged in stator slots 7 of the stator base 5, and the paired hairpin ends 12 of the hairpins 8 are connected to each other, for example by welding or brazing.

[0049] Furthermore, the motor 3 has a rotor 15, which is rotatably arranged within the stator 2 about the longitudinal axis 6 of the stator 2's base. Additionally, the motor 3 has a multi-part housing 19 to protect the stator 2 and rotor 15 from external influences and to better mount the motor 3 within the vehicle 4. For targeted energization of the stator 2 to operate the motor 3, the motor 3 has power electronics 20 with its own housing. The power electronics 20 are electrically connected to the stator 2.

[0050] Figure 8 A preferred embodiment of a motor vehicle 4 according to the invention is schematically shown in a side view. The motor vehicle 4 has an electric drive system 16, which includes a motor 3 according to the invention and a traction battery 21 for storing and providing electrical energy for operating the motor 3.

[0051] exist Figure 9The preferred embodiment of the method according to the invention is illustrated schematically in a flowchart. In the first method action 100, a stator base 5 is provided. The stator base 5 extends about and along the longitudinal axis 6 of the base, and is therefore generally hollow cylindrical. Stator slots 7 are formed in the stator base 5, extending parallel to the longitudinal axis 6 of the base and designed to open axially toward and towards the longitudinal axis 6 of the base.

[0052] In the second method action 200, the hairpin 8 is arranged in the stator slot 7. This is preferably accomplished by inserting the hairpin 8 into the stator slot 7 in the axial direction. The hairpin 8 is arranged in a plurality of slot positions in the stator slot 7 with respect to the slot depth formed in the radial direction of the stator slot 7. In addition, the hairpin 8 is arranged in the stator slot 7 such that the hairpin end region 9 of the hairpin 8 protrudes from the stator slot 7 with the free hairpin end 10 on at least one end face of the stator base 5. The hairpin 8 is thus arranged in the initial position A.

[0053] In the third method action 300, the hairpin end region 9 is twisted by the twisting tool 11. Here, the hairpin end region 9 is preferably first twisted to an intermediate position Z in the first twist, and then twisted to a final position E in the second twist. Between the first and second twists, the twisting tool 11 may also move at the free end of the hairpin 10. At the final position E, the hairpin 8 is arranged obliquely relative to the longitudinal axis 6 of the base at the free hairpin end 10, and the hairpins 8 converge at the free hairpin end 10 to form an end pair 12. In the fourth method action 400, the end pair 12 is joined, for example, by welding, brazing, etc.

[0054] List of reference numerals

[0055] 1. Stator winding

[0056] 2. Stator

[0057] 3 motors

[0058] 4 Motor vehicles

[0059] 5. Stator substrate

[0060] 6. Matrix longitudinal axis

[0061] 7 stator slots

[0062] 8 hair clips

[0063] 9. Hairpin end area

[0064] 10 Free hairpin ends

[0065] 11 Twist tool

[0066] 12-end pair

[0067] 13 First Curving Area

[0068] 14 Second Curving Area

[0069] 15 Rotors

[0070] 16 Electric drive system

[0071] 17 First Accommodation Department

[0072] 18 Second Accommodation Department

[0073] 19 Machine casing

[0074] 20 Power Electronic Devices

[0075] 21 Traction Battery

[0076] A. Initial position

[0077] E's final position

[0078] Z middle position

[0079] 100 First Method Actions

[0080] 200 Second Method Action

[0081] 300 Third Method Action

[0082] 400 Fourth Method Action

Claims

1. A method for manufacturing a stator winding (1) of a stator (2) of an electric machine (3) for driving a motor vehicle (4), the method having: - providing a stator base body (5) having a base body longitudinal axis (6) and a plurality of stator slots (7), - arranging hairpins (8) in the stator slots (7) such that hairpin end regions (9) of the hairpins (8) protrude from the stator slots (7) on a base body end face of the stator base body (5) with free hairpin ends (10), - twisting the hairpin end regions (9) from an initial position (A) to a final position (E) with a twisting tool (11) such that the hairpins (8) are arranged inclined to the base body longitudinal axis (6) at the free hairpin ends (10) and the hairpins (8) converge into end pairs (12) at the free hairpin ends (10), and - connecting the end pairs (12).

2. The method according to claim 1, characterized in that the twisting of the hairpin end regions (9) from the initial position (A) to the final position (E) is performed using the same twisting tool (11).

3. The method according to claim 1 or 2, characterized in that the twisting of the hairpin end regions (9) from the initial position (A) to the final position (E) is performed in a multi-stage process through an intermediate position (Z), wherein the intermediate position (Z) is located between the initial position (A) and the final position (E).

4. The method according to claim 3, characterized in that the twisting of the hairpin end regions (9) from the initial position (A) to the final position (E) is performed first using the twisting tool (11) from the initial position (A) to the intermediate position (Z), then transferring the twisting tool (11) to the hairpin end regions (9), and finally twisting the hairpin end regions (9) from the intermediate position (Z) to the final position (E).

5. The method according to claim 4, characterized in that the transferring of the twisting tool (11) is performed such that the twisting tool (11) has a greater distance to the stator base body (5) immediately after the transferring than immediately before the transferring.

6. The method according to any one of claims 3 to 5, characterized in that the twisting is performed in such a way that the free hairpin ends (10) roll on the twisting tool (11) between the intermediate position (Z) and the final position (E).

7. The method according to any one of the preceding claims, characterized in that the twisting is performed in such a way that the hairpin end regions (9) each have a first curved region (13) close to the stator base body (5) and a second curved region (14) away from the stator base body (5), the first curved region (13) having a first degree of curvature which is greater than a second degree of curvature of the second curved region (14).

8. The method according to any one of the preceding claims, characterized in that the twisting is performed in such a way that the free hairpin ends (10) of the end pairs (12) are arranged at an angle to each other of between 50° and 150°.

9. An electric machine (3) for driving a motor vehicle (4), the electric machine having a stator (2) with a stator winding (1) and a rotor (15) rotatably supported relative to the stator (2), characterized in that ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The stator winding (1) is manufactured by the method according to any one of the preceding claims.

10. Motor vehicle (4) having an electric drive system (16), characterized in that The electric drive system (16) for driving the motor vehicle (4) has an electric machine (3) according to claim 9.

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