Method for producing stator, electric machine and motor vehicle

Abstract

The invention relates to a method for producing a stator (1) for an electric machine (2) for driving a motor vehicle (3). The invention relates to a method for producing a stator for a motor vehicle, comprising: providing a stator base body (4) having a plurality of stator slots (5), arranging a hairpin (6) in the stator slots (5), the hairpin end side (9) of the hairpin (6) having a concave end contour (10) which extends towards a hairpin end surface (8) of a hairpin end (7) protruding from the stator slots (5), and-twisting the hairpin end (7) in the circumferential direction (U) of the stator base body (4) by engaging a twisting tool in the concave end contour (10) and applying a twisting force to the hairpin end (7) in the circumferential direction (U) by the twisting tool. The invention further relates to an electric machine (2) for driving a motor vehicle (3) and to a motor vehicle (3) having an electric drive system (11).

Description

TECHNICAL FIELD

[0001] The present application relates to a method for manufacturing a stator for an electric machine for driving a motor vehicle. Furthermore, the present application relates to an electric machine for driving a motor vehicle and to a motor vehicle with an electric drive system. BACKGROUND

[0002] A large number of different stators for electric machines for driving motor vehicles are known. For reasons of efficiency, the stators of electric traction drives usually have stator windings which are configured as inserted windings. Such stators are also referred to as "Hairpin-Stators", since the stator wires used to produce the inserted windings resemble the shape of a hairpin.

[0003] The stator wires for hairpin stators are essentially divided into two different types, U-pins and I-pins. U-pins have two legs which are arranged in parallel and which are connected to one another in a curved intermediate region. The legs each have a free end at the side facing away from the intermediate region. I-pins are configured as rods and correspond essentially to the legs of the U-pins. The free ends of the U-pins and I-pins each have a hairpin end face.

[0004] In the manufacture of hairpin stators, a stator base body with stator slots is first provided. In a next step, the hairpins are inserted into the stator slots in such a way that the hairpins protrude from the stator base body on both sides. Subsequently, the free hairpin ends are widened and twisted using a tool. Since the end sections of the free hairpin ends are gripped by the tool in this process, they continue to protrude in the axial direction from the stator base body. Finally, the end sections are each welded to one another in pairs. In this way, a multiphase stator winding is produced. Such a method is known, for example, from document US 2006 / 0 267 440 A1. Document DE 10 2019 130 534 A1 shows a device for carrying out such a method. Disadvantageously in such stators, the protruding end sections of the free hairpin ends occupy a relatively large amount of space.

[0005] An alternative manufacturing method for a stator is known from document WO 2023 / 233 618 A1. The end sections of the free hairpin ends are configured to be significantly shorter. Furthermore, only one hairpin end of a pair of hairpins to be welded to one another is twisted, while the other hairpin end protrudes in the axial direction from the stator base body. In this way, additional radial guidance is provided when twisting, so that less space is required for the tool for twisting. Document US 11 710 999 B2 likewise discloses a method in which all free hairpin ends are twisted. After the twisting, the protruding end regions of the hairpin ends are cut off. In order to weld adjacent hairpin ends together in pairs, a holding tool is provided. Disadvantageously, there is a relatively high material waste by cutting the end regions to size. SUMMARY

[0006] It is therefore the task of the present application to eliminate or at least partially eliminate the above-described disadvantages in a stator for an electric machine for driving a motor vehicle. In particular, it is the task of the present application to create a method for manufacturing a stator for an electric machine for driving a motor vehicle, an electric machine for driving a motor vehicle and a motor vehicle with an electric drive system which has particularly compact construction dimensions and / or avoids excess material waste in a simple and cost- appropriate manner.

[0007] This task is solved by a method for manufacturing a stator for an electric machine for driving a motor vehicle according to the present application, by an electric machine for driving a motor vehicle according to the present application and by a motor vehicle with an electric drive system according to the present application. Further features and details of the present application result from the description and the drawings. Here, the features and details described in connection with the method according to the present application apply mutatis mutandis also in connection with the electric machine according to the present application and the motor vehicle according to the present application, and vice versa, so that with regard to the disclosure of the respective inventive aspects always or can be mutually referred to.

[0008] According to a first aspect of the present application, the task is solved by a method for manufacturing a stator for an electric machine for driving a motor vehicle. The method has

[0009] - providing a stator base body with a multiplicity of stator slots,

[0010] - arranging hairpins in the stator slots in such a way that the hairpins are arranged in the stator slots in a plurality of hairpin positions in the radial direction of the stator base body and the hairpin ends of the hairpins protrude from the stator base body in the axial direction of the stator base body, wherein the hairpin ends each have a hairpin end face limiting the hairpin end in the longitudinal direction of the hairpin, wherein the hairpin end side of the hairpin has a concave end contour which extends towards the hairpin end face, and

[0011] - torsioning the clasp end in the circumferential direction of the stator base by engaging a torsion tool into the concave end contour and by the torsion tool applying a torsion force in the circumferential direction onto the clasp end.

[0012] First, a stator base is provided. The stator base is preferably manufactured from a large number of plates which are coaxially stacked and connected to one another. The plates are preferably manufactured from electrical plates and further preferably each have a coating, in particular a coating which electrically insulates, such as, for example, a Backlack or the like. The stator base extends along a stator longitudinal axis.

[0013] A plurality of stator slots is arranged in the stator base for accommodating the clasps. The stator slots preferably extend parallel to the stator longitudinal axis and have a slot depth in the radial direction. The slot depth preferably corresponds to a multiple of a clasp thickness of the clasps, wherein the clasp thickness is to be understood as the thickness of the wire from which the clasp is formed. A plurality of clasp positions can thus be arranged in the stator slots in the radial direction on top of one another.

[0014] A slot width of the stator slots preferably corresponds to a clasp width of the clasps, wherein the clasp width is to be understood as the width of the wire from which the clasp is formed. In the assembled state, the clasp width is oriented in the circumferential direction or tangential direction. Preferably, a slot insulation material is respectively arranged in the stator slots for electrically insulating the stator slots with respect to the clasps. The slot insulation material can be configured, for example, as an insulation paper.

[0015] The clasps are arranged in the stator slots in the plurality of clasp positions. A plurality of clasps is thus respectively arranged side by side in the stator slots in the radial direction. Furthermore, the arrangement of the clasps is carried out such that the clasp ends of the clasps protrude from the stator base in the axial direction of the stator base. Thus, in the case of an I-shaped lead, the free clasp ends of the clasps protrude from the stator base on both sides. In the case of a U-shaped lead, the free clasp ends protrude from the stator base on one side. The curved middle region of the clasp protrudes from the other side of the stator base.

[0016] In order to carry out the method according to the application, a clasp is used in which the clasp ends respectively have a clasp end face which limits the clasp in the longitudinal direction of the clasp. Furthermore, the clasp end side of the clasp has a concave end contour which extends towards the clasp end face. By means of the concave end contour, it is ensured that a torsion tool engages into the clasp end region, in which the torsion tool is prevented from slipping laterally from the clasp in a form-fit manner when being torsioned. The concave end contour can thus also be referred to as a guide geometry. Preferably, the concave end contour extends to the clasp end face.

[0017] The hairpin is preferably made of copper or the like. Preferably, the hairpin has a cover layer which acts electrically insulating, which is formed for example by wire lacquer or the like. In order to ensure the electrical contacting of the hairpin, the end regions of the hairpin ends which are to be electrically coupled to one another and which are to be connected, for example by soldering, brazing, crimping or the like, are preferably abisoliert or at least do not have a cover layer which acts electrically insulating. The concave end contour thus preferably does not have a cover layer which acts electrically insulating.

[0018] Preferably, the additional widening of the hairpin end projecting from the stator base in the radial direction on the base side of the stator base is carried out by means of a tool which is configured for this purpose. By the widening, a higher process reliability is ensured when twisting and electrically coupling and mechanically connecting, such as for example soldering, brazing, crimping or the like. Thus, the twisting can be carried out in particular with little friction, without the adjacent hairpin ends sliding over one another. The soldering or brazing is improved by the widening in such a way that unintentional solder bridges or brazing bridges to the adjacent hairpin end pair are better avoided. The crimping is improved in such a way that more space is provided for the crimping tool.

[0019] Subsequently, the twisting of the hairpin ends in the circumferential direction of the stator base is carried out by means of a twisting tool. For this purpose, the twisting tool engages into the concave end contour of the hairpin ends and exerts a force on the hairpin ends in the circumferential direction. The twisting is preferably carried out in such a way that directly adjacent hairpin ends are twisted in opposite directions in the circumferential direction. The radial guidance of the hairpin ends when twisting is ensured by the interaction of the twisting tool with the concave end contour, so that additional radial support means which are arranged laterally to the hairpin in the radial direction are dispensed with in the case of the twisting tool. The wire head of the stator can thus be configured particularly space-savingly.

[0020] The method according to the application for producing a stator for an electric machine for driving a motor vehicle has the advantage over conventional methods that the stator can be produced in a simple manner and in a cost- appropriate way, which has a particularly compact wire head. Due to the concave end contour, a direct force introduction onto the hairpin ends from the twisting tool can be achieved when twisting, so that additional pressing, guiding and shaping steps can be omitted. Furthermore, no additional protruding hairpin end regions are thus required, for example for establishing a clamping by means of the twisting tool, which either require additional construction space or lead to additional material consumption due to the stator base being cut to size.

[0021] According to a preferred refinement of the application, it can be provided in the method for producing a stator that hairpins with a rectangular cross section are used. It is preferred here that the hairpin width, i.e. the extension of the hairpin wire of the hairpin in the circumferential direction or in the tangential direction, is greater than the hairpin thickness, i.e. the extension of the hairpin wire in the radial direction. By means of the rectangular cross section, it is possible to better avoid the hairpin from being twisted around the longitudinal axis of the hairpin when being twisted. Furthermore, the hairpin with the rectangular cross section has flat sides which can be more easily brought together with the other sides of the adjacent hairpin end. This has the advantage that the production of the stator is further improved in a simple manner and in a cost- appropriate way.

[0022] It is preferred according to the application that hairpins are used in which the hairpin end faces have a rectangular cross section, a trapezoidal cross section, a pentagonal cross section or a rectangular cross section with concave sides. The concave end profile preferably extends on the longitudinal sides of the hairpin, which extends in the thickness direction of the hairpin and in the longitudinal direction of the hairpin. In the case of a rectangular cross section, the concave end profile is preferably configured as a uniform indentation on the longitudinal sides, wherein the concave end profile extends around an axis oriented parallel to the thickness direction of the hairpin. In the case of a trapezoidal cross section, the concave end profile is preferably configured as an asymmetric indentation on the longitudinal sides, for example by different depths with respect to the longitudinal sides without the concave end profile. The concave end profile thus extends around an axis oriented oblique to the thickness direction of the hairpin. In the case of a pentagonal cross section, the concave end profile is preferably formed by the concave end profile with directly adjoining chamfers or the like. In the case of a rectangular cross section with concave sides, the concave end profile is preferably configured as a symmetric indentation on the longitudinal sides, wherein the concave end profile extends around an axis oriented parallel to the longitudinal direction of the hairpin. This has the advantage that the production of the stator is further improved in a simple manner and in a cost-advantageous way.

[0023] It is further preferred to use hairpins in which two adjacent hairpin end sides of the hairpin have a concave end profile which extends to the same hairpin end face. The hairpin end face thus preferably has a pentagonal cross section. It is further preferred that the two adjacent concave end profiles preferably have a common separating edge. It is preferred that the two adjacent concave end profiles are configured differently wide. This has the advantage that the production of the stator is further improved in a simple manner and in a cost- appropriate way.

[0024] In a particularly preferred design of the application, it can be provided in the method for producing the stator that hairpins are used which are configured as U-shaped leads, wherein the concave end contours of the hairpin ends face one another. The U-shaped lead has two legs which are connected to one another by a bent intermediate region by approximately 180°. Preferably, the U-shaped lead is configured as a whole such that the two legs and the intermediate region are produced from an I-shaped lead, for example, by a reforming process. The concave end contours are thus arranged completely or at least partially on the inner side of the legs. This has the advantage that the production of the stator is further improved in a simple manner and in a cost- appropriate manner.

[0025] Preferably, the torsion tool rolls on the concave end contours when being twisted. To this end, the torsion tool can have, for example, a rolling section which is preferably configured as convex. The rolling section preferably has a smaller radius than the concave end contours. By applying pressure from the torsion tool to the concave end section in the circumferential direction or tangential direction, the hairpin can be bent such that the rolling section rolls on the concave end contours. Furthermore, the hairpin is prevented from bending away in the radial direction by the end section being engaged into the concave end contours in a form-fit. This has the advantage that the production of the stator is further improved in a simple manner and in a cost- appropriate manner.

[0026] According to a preferred embodiment of the application, after the torsion, the hairpin ends are connected to one another in pairs in a welding position in an electrically coupled manner, wherein the hairpin ends are held in the welding position by the torsion tool for the connection. In the context of the application, the welding position is understood to be the relative position of the hairpin ends in which they are arranged for the electrically coupled connection in pairs to form the stator winding. In the context of the application, the welding position can also be understood to be the relative position of the hairpin ends in which they are arranged for the welding, brazing, crimping, etc. in pairs to form the stator winding. According to the application, it can be provided that, in the welding position, the stripped hairpin ends of the hairpins are in contact in pairs. Holding the hairpin ends in the welding position is preferably effected by the torsion tool remaining in an end position which it occupies directly at the end of the torsion process when no further bending of the hairpins is carried out. Holding in the welding position is thus preferably effected by maintaining the pressure on the concave end contours by the torsion tool providing a support. In addition, the pressure preferably presses the hairpin ends to be welded to one another in the radial direction against one another. The subsequent welding process, brazing process, crimping process, etc. can thus be carried out more easily and more reliably. This has the advantage that the production of the stator is further improved in a simple manner and in a cost- appropriate manner.

[0027] It is particularly preferred that, when the end contour of the recess is twisted, a circumferential pressure component and a radial pressure component are transmitted to the end contour of the recess by means of the twisting tool. It is particularly preferred that the end contour of the recess is configured in such a way that the transmission of the pressure components is facilitated. Thus, the end contour of the recess is preferably configured in such a way that at least one face normal at the end contour of the recess at the point of engagement with the twisting tool when the end contour of the recess is twisted has a directional component in the radial direction and a directional component in the circumferential direction or tangential direction. Thereby, a stable guidance of the hairpin end is ensured and the risk of the hairpin end slipping in the radial direction is reduced. Additional guiding means of the twisting tool for guiding the hairpin end when the end contour of the recess is twisted can thus be omitted. This has the advantage that the manufacture of the stator is further improved in a simple manner and in a cost- appropriate way.

[0028] According to a second aspect of the application, the task is solved by an electric machine for driving a motor vehicle. The electric machine has a stator with a stator base body and stator windings formed by hairpins, and a rotor rotatably supported relative to the stator. According to the application, the stator is manufactured by a method for manufacturing a stator for an electric machine for driving a motor vehicle according to the application.

[0029] Thus, the stator has a stator base body with a large number of stator slots. A plurality of hairpins is arranged in the stator slots in such a way that the hairpins are arranged in the stator slots in a plurality of hairpin positions in the radial direction of the stator base body and the hairpin ends of the hairpins protrude from the stator base body in the axial direction of the stator base body. On at least one end side of the stator base body, the hairpin ends are twisted and welded, brazed, crimped, etc. to one another in pairs. On the other end side of the stator base body, the hairpin ends can likewise be twisted and welded, brazed, crimped, etc. to one another in pairs. Alternatively, on the end sides of the stator base body, respectively two hairpins can be connected to one another by an intermediate region which is configured integrally with the hairpins. In both cases, the stator has a wire end on both stator end sides. In this way, a multiphase stator winding is formed.

[0030] The electric machine according to the application differs from conventional electric machines in the configuration of the stator, in particular of the hairpins. The hairpin ends of the hairpins which protrude from the stator base body and are respectively electrically coupled and connected to one another, for example welded, brazed, crimped, etc., in pairs to form a multiphase stator winding respectively have a hairpin end face which limits the hairpin end in the longitudinal direction of the hairpin, wherein the hairpin end side of the hairpin has a recessed end contour which extends to the hairpin end face. By this configuration of the hairpin end, the manufacture of the stator is significantly improved.

[0031] All advantages already described for the method for manufacturing a stator for an electric machine for driving a motor vehicle according to the first aspect of the application are derived in the electric machine for driving a motor vehicle according to the application. Thus, the electric machine according to the application has the advantage over conventional electric machines that the stator is provided in a simple means and in a cost- appropriate manner, which has particularly compact wire ends. Due to the concave end profile, a direct force introduction from the twisting tool into the hairpin end is achieved upon twisting, so that additional pressing, guiding and shaping steps are omitted. Furthermore, no additional protruding hairpin end regions are thus required, for example for establishing a clamping by the twisting tool, which either require additional construction space or lead to additional material consumption due to the gauge cutting.

[0032] According to the third aspect of the application, the task is solved by a motor vehicle. The motor vehicle has an electric drive system with a traction battery. According to the application, the electric drive system has an electric machine according to the application for driving the motor vehicle.

[0033] The traction battery is configured for providing electrical energy for operating the electric machine.

[0034] All advantages already described for the method for manufacturing a stator for an electric machine for driving a motor vehicle according to the first aspect of the application and for the electric machine for driving a motor vehicle according to the second aspect of the application are derived in the motor vehicle according to the application. Thus, the motor vehicle according to the application has the advantage over conventional motor vehicles that the stator is provided in a simple means and in a cost- appropriate manner, which has particularly compact wire ends. Due to the concave end profile, a direct force introduction from the twisting tool into the hairpin end is achieved upon twisting, so that additional pressing, guiding and shaping steps are omitted. Furthermore, no additional protruding hairpin end regions are thus required, for example for establishing a clamping by the twisting tool, which either require additional construction space or lead to additional material consumption due to the gauge cutting. BRIEF DESCRIPTION OF DRAWINGS

[0035] The electric machine according to the application, the motor vehicle according to the application and the method according to the application are explained in more detail below with the aid of the drawings. Respectively schematically:

[0036] Figure 1 A stator for an electric machine according to the preferred first embodiment of the application is shown in a perspective view,

[0037] Figure 2 A hairpin from the electric machine according to Figure 1 is shown in a perspective view,

[0038] Figure 3A stator during a first point in time when executing the method according to the application is shown in a side view,

[0039] Figure 4 A stator during a second point in time when executing the method according to the application is shown in a side view,

[0040] Figure 5 A stator during a third point in time when executing the method according to the application is shown in a side view,

[0041] Figure 6 A hairpin end according to the preferred first embodiment of the application is shown in a perspective view,

[0042] Figure 7 A hairpin end according to the preferred second embodiment of the application is shown in a perspective view,

[0043] Figure 8 A hairpin end according to the preferred third embodiment of the application is shown in a perspective view,

[0044] Figure 9 A hairpin end according to the preferred fourth embodiment of the application is shown in a perspective view, and

[0045] Figure 10 A preferred embodiment of a motor vehicle according to the application is shown in a side view.

[0046] In the drawings Figures 1 to 10 Elements with the same function and the same principle of action are provided with the same reference symbols in the various figures. DETAILED DESCRIPTION

[0047] In the drawings Figure 1 A stator 1 for an electric machine 2 for driving a motor vehicle 3 according to the preferred first embodiment of the application is shown schematically in a perspective view. The stator 1 has a stator base body 4 which has a large number of stator slots 5. The stator slots 5 have a slot depth in the radial direction R and extend through the stator base body 4 in the axial direction A. A plurality of hairpins 6 configured as U-shaped lead wires are arranged in the stator slots 5 in such a way that the hairpins 6 are arranged in the stator slots 5 in a plurality of hairpin positions and project on both sides from the stator base body 4 in the axial direction A.

[0048] The hairpins 6 have a hairpin end 7 which projects on one side from the stator base body 4 in the axial direction A. The hairpins 6 have an electrically insulating coating, wherein no electrically insulating coating is arranged at the end region of the hairpin end 7. The hairpin ends 7 are twisted in the circumferential direction U and are welded to one another in pairs.

[0049] Figure 2 A stator during a second point in time when executing the method according to the application is shown in a side view, Figure 1The hairpin 6 of the motor 2. The hairpin 6 is constructed with a U-shaped lead and has two parallel legs 13 extending in the longitudinal direction L, which are connected to each other by a 180° intermediate region 14. The legs 13 and the intermediate region 14 are integrally constructed. The hairpin 6 has a rectangular cross-section. The two free hairpin ends 7 of the hairpin 6 are respectively limited by hairpin end faces 8. Concave end profiles 10 are respectively constructed on the hairpin end sides 9 facing each other, which extend to the hairpin end faces 8.

[0050] exist Figure 3 The stator 1 is schematically depicted in a side view during a first time point when the method according to the invention is performed. At the first time point, a stator base 4 with a plurality of stator slots 5 is provided, in which hairpins 6 are arranged in a plurality of hairpin positions. The free hairpin ends 7 of the hairpins 6 extend from the stator base 4 in the axial direction A. Concave end profiles 10 are respectively formed at the end regions of the hairpin ends 7.

[0051] Figure 4 The stator 1 is schematically shown in a side view during a second time point when the method according to the invention is performed. At the second time point, the hairpin end 7 widens in the radial direction R. Figure 5 The stator 1 is schematically depicted in a side view during a third time point when the method according to the invention is performed. At the third time point, the hairpin end 7 is twisted in the circumferential direction U and arranged in the welding position V for pair welding.

[0052] Figure 6 The hairpin end 7 according to a preferred first embodiment of the invention is schematically shown in perspective. Hairpin 6 (see also...) Figure 2 It has a rectangular cross-section. The hairpin end 7 is limited in the longitudinal direction L by the hairpin end face 8. Concave end profiles 10 are constructed on two adjacent hairpin end sides 9, which extend to the hairpin end face 8. Therefore, the hairpin end face 8 is constructed as a trapezoid. The concave end profiles 10 are curved about an axis constructed inclined in the longitudinal direction L.

[0053] exist Figure 7 The hair clip end 7 according to a preferred second embodiment of the invention is schematically shown in perspective view. Hair clip 6 (see also...) Figure 2 It has a rectangular cross-section. The hairpin end 7 is limited in the longitudinal direction L by the hairpin end face 8. A concave end profile 10 is constructed on the hairpin end side 9, which extends to the hairpin end face 8. Therefore, the hairpin end face 8 is constructed to be rectangular. The concave end profile 10 is curved about an axis constructed perpendicular to the longitudinal direction L.

[0054] Figure 8A hairpin end 7 according to a preferred third embodiment of the application is shown schematically in a perspective view. The hairpin 6 (see Figure 2 ) has a rectangular cross section. The hairpin end 7 is limited in the longitudinal direction L by a hairpin end face 8. On two adjacent hairpin end sides 9, concave end contours 10 are configured which extend to the hairpin end face 8 and have a common side edge in the longitudinal direction L. The concave end contours 10 have different widths. The hairpin end face 8 is thus configured pentagonally. One of the concave end contours 10 curves around an axis which is configured perpendicular to the longitudinal direction L. The other of the concave end contours 10 curves around an axis which is configured obliquely to the longitudinal direction L.

[0055] A hairpin end 7 according to a preferred fourth embodiment of the application is shown schematically in a perspective view in Figure 9 . The hairpin 6 (see Figure 2 ) has a rectangular cross section. The hairpin end 7 is limited in the longitudinal direction L by a hairpin end face 8. On two adjacent hairpin end sides 9, concave end contours 10 are configured which extend to the hairpin end face 8 and have a common side edge. The concave end contours 10 have different widths. The hairpin end face 8 is thus configured pentagonally. One of the concave end contours 10 curves around an axis which is configured perpendicular to the longitudinal direction L. The other of the concave end contours 10 curves around an axis which is configured obliquely to the longitudinal direction L.

[0056] Figure 10 A preferred embodiment of a motor vehicle 3 according to the application is shown schematically in a side view. The motor vehicle 3 has an electric drive system 11 with an electric machine 2 according to the application for driving the motor vehicle 3 and a traction battery 12 for providing electrical energy for operating the electric machine 2.

[0057] List of reference symbols

[0058] 1 stator

[0059] 2 electric machine

[0060] 3 motor vehicle

[0061] 4 stator base body

[0062] 5 stator slot

[0063] 6 hairpin

[0064] 7 hairpin end

[0065] 8 hairpin end face

[0066] 9 hairpin end side

[0067] 10 concave end contour

[0068] 11 electric drive system

[0069] 12 traction battery

[0070] 13 leg

[0071] 14 intermediate region

[0072] A axial direction

[0073] L longitudinal direction

[0074] R radial direction

[0075] U circumferential direction

[0076] V welding position

Claims

1. A method for manufacturing a stator (1) for a motor (2) used to drive a motor vehicle (3), comprising: - Provides a stator base (4) with a large number of stator slots (5), - A hairpin (6) is arranged in the stator slot (5) such that the hairpin (6) is arranged in the stator slot (5) at multiple hairpin positions in the radial direction (R) of the stator base (4), and the hairpin end (7) of the hairpin (6) extends from the stator base (4) in the axial direction (A) of the stator base (4), wherein, The hairpin ends (7) each have a hairpin end face (8) that restricts the hairpin (6) in the longitudinal direction (L) of the hairpin (6), wherein the hairpin end side (9) of the hairpin (6) has a concave end profile (10) that extends toward the hairpin end face (8), and - By engaging the twisting tool into the concave end profile (10) in the concave direction (U) of the stator base (4), the hairpin end (7) is twisted and the twisting tool applies a torsional force to the hairpin end (7) in the circumferential direction (U).

2. The method according to claim 1, Its features are, Use a hair clip with a rectangular cross-section (6).

3. The method according to claim 2, Its features are, The hair clip (6) is used in which the end face (8) of the hair clip has a rectangular cross-section, a trapezoidal cross-section, a pentagonal cross-section or a rectangular cross-section with a concave side.

4. The method according to any one of the preceding claims, Its features are, Using a hairpin (6) in which two adjacent hairpin end sides (9) have concave end profiles (10) that extend to the same hairpin end face (8).

5. The method according to any one of the preceding claims, Its features are, The following hairpin (6) is used, wherein the hairpin is constructed as a U-shaped lead, wherein the concave end profiles (10) of the ends (7) of the hairpin face each other.

6. The method according to any one of the preceding claims, Its features are, The twisting tool rolls on the concave end profile (10) during twisting.

7. The method according to any one of the preceding claims, Its features are, The hairpin ends (7) are electrically coupled to each other in pairs in the welding position (V) after being twisted, wherein the hairpin ends (7) are held in the welding position (V) by the twisting tool for connection.

8. The method according to any one of the preceding claims, Its features are, When twisting on the concave end profile (10), the pressure component in the circumferential direction (U) and the pressure component in the radial direction (R) are transferred to the concave end profile (10) using the twisting tool.

9. An electric motor (2) for driving a motor vehicle (3), having a stator (1) with a stator base (4) and stator windings formed by hairpins (6) and a rotor rotatably supported relative to said stator (1), Its features are, The stator (1) is manufactured by the method according to any one of the preceding claims.

10. A motor vehicle (3) having an electric drive system (11) with a traction battery (12), Its features are, In order to drive the motor vehicle (3), the electric drive system (11) has a motor (2) according to claim 9.

Images