ELECTRIC MACHINE, MOTOR VEHICLE AND METHOD FOR MAKING A WINDING FOR AN ELECTRIC MACHINE

Description

[0001] The invention relates to an electrical machine having a winding support with multiple slots, which supports at least one winding, wherein the winding is formed by a conductor having multiple slot sections, each extending within one of the slots of the winding support and being conductively connected by connecting sections of the conductor lying outside the slots, wherein the winding comprises multiple conductor clamps which are conductively connected to one another and each form two slot sections and a coupling section connecting the slot sections, wherein the individual conductor clamps are inclined with respect to the radius of the winding support such that a first free end of the respective conductor clamp lies in a lower winding plane than a second free end of the conductor clamp. The invention also relates to a motor vehicle and a method for producing a winding for an electrical machine.

[0002] A so-called hairpin design is now frequently used, particularly for drive motors in motor vehicles. In this manufacturing technique, a profile wire, usually a rectangular wire, is first bent into a U-shape, i.e., the shape of a hairpin. The legs of this hairpin are then arranged in a circle and inserted into the slots of a stator core. In the next step, the free ends of each hairpin are twisted concentrically to the stator axis by a defined angle. In this process, all ends that lie on a particular diameter, i.e., at a specific position in the slots, are alternately twisted clockwise and counterclockwise. This is also referred to as "twisting."

[0003] The adjacent ends are welded together. Depending on the winding pattern, connecting bridges are placed on the angle head and welded to the corresponding ends of hairpins to connect the hairpins to form a complete winding. If necessary, the pin ends are then insulated and the entire stator is impregnated. This technology enables a high level of automation and a high copper fill factor in the stator slots, i.e., a high ratio between copper area and slot area. This design is therefore particularly popular for electric motors in the automotive sector.

[0004] When manufacturing a stator in this way, it can be problematic that there are a relatively high number of intersections between conductor sections of different electrical phases in the winding overhang. In motors with high intermediate circuit voltages, this places a heavy strain on the electrical insulation. It may therefore be necessary to use relatively thick insulation layers, which, however, leads to a reduction in the copper fill factor. Alternatively or additionally, attempts can be made to further improve the high-voltage strength of the insulation using special insulation materials. A large number of high-voltage-resistant insulation materials are known. Purely as an example, reference is made to the document DE 37 18 449 A1. Despite the possible improvements in insulation through the selection of an appropriate insulation material, the insulation layer still consumes a relatively high amount of slot area.

[0005] A stator of a drive motor with a hairpin winding is known from publication KR 2018 0057949 A. A conductor located furthest inside a conductor stack of the respective slot can have a smaller conductor cross-section or a thicker insulating coating than the other conductors in the slot.

[0006] The document EP 1 381 140 A2 relates to hairpin windings for electrical machines in which the respective winding is formed by conductor clamps connected in series.

[0007] The invention is therefore based on the object of specifying an electrical machine which can achieve the required insulation of the conductors of the electrical machine from one another with less area consumption in slots of a winding carrier, for example a stator laminated core.

[0008] The object is achieved by the independent claims. According to the invention, in an electrical machine of the type mentioned at the outset, the conductor has an insulating layer applied to the conductor at least in the slot sections, wherein the insulating layer has a different layer thickness for at least two of the slot sections, wherein both slot sections of a first of the conductor clamps have an insulating layer with a first layer thickness and wherein both slot sections of a second of the conductor clamps have an insulating layer with a second layer thickness different from the first layer thickness.

[0009] Within the scope of the invention, it was recognized that high voltages between intersecting conductors of different phases generally only occur for a relatively small number of turns or slot feedthroughs of the respective winding. Voltage peaks or voltage increases are to be expected, particularly in the first few turns after the phase input. These effects occur in many winding and wiring schemes for electrical machines. By using different layer thicknesses for the insulation layers of different slot sections, it is possible to ensure that particularly thick layers are only used in areas where particularly high voltages occur. This can increase the overall copper fill factor of the slots.It was also found that, as will be explained in more detail later, the use of different layer thicknesses for the insulation layers in a hairpin winding design can be implemented with little technical effort.

[0010] The layer thickness of the insulation layer differs from one another for the two groove sections by at least 5%, at least 10%, or at least 50%. In particular, the layer thickness of one of the groove sections is at least 2 times or at least 3 times greater than the layer thickness of the other groove section. Particularly preferably, several of the groove sections have a greater layer thickness of the insulation layer than the remaining groove sections.

[0011] The winding support can, in particular, be a stator body, for example, a stator core, or the winding can, in particular, be a stator winding. The winding support preferably supports multiple windings, wherein each of the windings in particular comprises slot sections with insulation layers of varying thicknesses.

[0012] In particular, as will be explained in more detail later, the conductor is composed of individual conductor sections that form the continuous conductor in the finished winding. The individual conductor sections can, for example, be welded together or otherwise conductively connected.

[0013] The insulation layer preferably extends beyond the respective slot section and at least over a portion of the connecting section. In particular, the insulation layer extends at least into that portion of the winding head where conductors of different windings or different phases intersect.

[0014] The sum of the cross-sectional areas of the conductor and the insulation layer in a first of the slot sections can be equal to the sum of the cross-sectional areas of the conductor and the insulation layer in a second of the slot sections, in which the insulation layer has a different layer thickness than in the first slot section. In particular, this sum can be the same for all slot sections of the winding. This can be achieved for the first and second slot sections or for all slot sections by reducing the cross-sectional area of the conductor in the slot section or in those slot sections in which a thicker insulation layer is used. In particular, the insulation layer can have the same outer diameter in cross section for the first and second slot sections or for all slot sections. This can improve the handleability of the conductor orThe handling of the conductor sections connected to the conductor during winding manufacture can be improved, since for such handling, only the external dimensions of the insulated conductor and thus the external dimensions of the insulation layer are relevant. For example, the conductor can be formed by a rectangular wire. In this case, the sum of the width of the conductor and twice the thickness of the insulation layer, or of the thickness of the conductor and twice the thickness of the insulation layer, can be the same for the first and second slot sections, in particular for all slot sections of the windings.

[0015] The winding comprises a plurality of interconnected conductor clamps, each having two groove sections and a coupling section connecting the groove sections. Both groove sections of a first of the conductor clamps have an insulating layer with a first layer thickness, and both groove sections of a second of the conductor clamps have an insulating layer with a second layer thickness different from the first layer thickness. The conductor clamps can, in particular, be the hairpins of a plug-in coil discussed above. The conductive connection can be realized, for example, by welding or soldering the free ends of the conductor clamps.

[0016] Preferably, each of the conductor clamps has an insulation layer with a substantially constant layer thickness, which extends at least over the groove sections and the coupling section. Preferably, the insulation layer can extend over the entire length of the conductor clamp, or over the entire length except for the end contact sections. Such conductor clamps are easy to manufacture by bending a wire with a constant insulation thickness into the shape of the conductor clamp. Preferably, a plurality of first and / or a plurality of second conductor clamps are used to form the winding.

[0017] The coupling section of the conductor clamp can form the connecting section for the two slot sections on one side. A connecting section to the next or preceding conductor clamp of the winding can be formed by the protruding free ends of the conductor clamp, which, as explained in the introduction, can be twisted and welded or otherwise conductively connected.

[0018] The first and second conductor clamps can have the same external dimensions. In particular, the first and second conductor clamps are both bent from a respective insulated wire, wherein the insulation has the same external dimensions. For those conductor clamps for which the insulation layer has a greater layer thickness, the dimensions of the conductor can be reduced accordingly, and vice versa. This allows the first and second conductor clamps to be handled together and in the same way, which can be particularly advantageous for automated insertion of the conductor clamps into the winding support and / or automated connection to the winding.

[0019] The slot sections can each have either a first layer thickness or a second layer thickness. In other words, exactly two different layer thicknesses of the insulation layers can be used for all slot sections of a winding, in particular for all slot sections of all windings arranged on the winding support. Production-related tolerances or production-related deviations from the first layer thickness and the second layer thickness can occur. For example, the actual layer thickness of an insulation layer can deviate from the first or second layer thickness by up to 5%, up to 10%, or up to 20% of the difference between the first and second layer thicknesses.

[0020] The conductor of the winding can extend from a first to a second winding terminal, wherein, when counting the slot sections along the conductor starting from the first and / or second winding terminal, the insulation layer of at least the first and / or second and / or third slot section has an insulation layer that has a greater layer thickness than the insulation layer of at least one slot section further away from the first and / or second winding terminal along the conductor. In particular, the layer thickness of the first and / or second and / or third slot section can be greater than the layer thickness of all insulation layers of slot sections that are further away from the first and second winding terminals along the conductor. As already mentioned, particularly high voltages potentially occur between conductors of different windings or phases close to winding terminals.Therefore, particularly thick insulation is preferably selected in this area. For example, when counting the slot sections along the conductor, at least the first three, or at least the first five, or at least the first seven slot sections can have thicker insulation than at least parts of the slot sections that are farther away from the winding terminals. For example, all slot sections adjacent to the winding terminals can have a first layer thickness, and the more distant slot sections can have a second layer thickness.

[0021] The insulation layer can be formed by a plastic sheath around the conductor. For example, polyetheretherketone (PEEK) can be used as the insulation layer material. The insulation can be applied using a plastic extrusion process. Compared to conventional insulation of a conductor with a varnish coating, this offers the advantage that the thickness of the insulation layer can be selected almost freely, whereas with varnish insulation, the thickness can only be varied within a narrow range. A copper conductor, for example, can be used as the conductor.

[0022] In addition to the electrical machine according to the invention, the invention relates to a motor vehicle comprising an electrical machine according to the invention.

[0023] The invention also relates to a method for producing a winding for an electrical machine, which comprises the following steps: Providing a winding support with a plurality of slots and a plurality of conductor clamps, each formed from a clamp-shaped conductor section and each forming two slot sections and a coupling section connecting the slot sections, wherein the conductor sections have an insulation layer applied to the conductor section at least in sections, namely at least in the slot sections, wherein the insulation layers of at least two conductor clamps have a different layer thickness from one another, so that both slot sections of a first of the conductor clamps have an insulation layer with a first layer thickness and both slot sections of a second of the conductor clamps have an insulation layer with a second layer thickness different from the first layer thickness, axially inserting the conductor clamps into the winding support in such a way that the individual conductor clamps are inclined relative to the radius of the winding support,that a first free end of the respective conductor clamp lies in a lower winding level than a second free end of the conductor clamp, and that the groove sections each extend within one of the grooves of the winding support, and connecting free ends of a respective group of conductor clamps to connect the conductor sections of these conductor clamps to a conductor of a winding, whereby the groove sections are conductively connected by connecting sections of the conductor lying outside the grooves.

[0024] The method according to the invention thus largely corresponds to a conventional procedure for producing, for example, a stator in a hairpin design. However, in contrast to the conventional procedure, conductor clamps or hairpins are used that have insulation layers of different thicknesses. As explained above, the conductor clamps with insulation layers of different thicknesses can, in particular, have the same external dimensions, so that, apart from the supply of different conductor clamps, the same manufacturing process can be used as for producing windings in a conventional hairpin winding. In particular, the same machines with the same settings can be used.

[0025] In larger series production, it is already common practice for conductor clamps or hairpins to be manufactured, particularly bent, on several machines operating in parallel. Therefore, equipping some of the bending machines with a differently insulated wire of the same size does not represent any significant additional effort. The subsequent process steps remain unaffected. The method according to the invention can thus be implemented with very little technical effort.

[0026] As explained above, the conductor clamps can be connected by twisting or twisting the free ends of the conductor clamps and then joining them, for example, by welding. After the steps described above, additional interconnection bridges can be placed on the resulting winding head and conductively connected, for example, by welding, to the ends of the conductor clamps to interconnect the conductor clamps into a complete winding.

[0027] In the method according to the invention or in the electrical machine according to the invention, it is possible for the entire conductor of the winding to be formed by the conductor clamps explained above. In this case, each of the conductor clamps forms two slot feedthroughs. In some cases, however, it may be desirable to use individual slot feedthroughs, for example to enable contact on an axially opposite side of the winding carrier or to provide a winding with an odd number of slot feedthroughs. In this case, linear pins can be used in addition to or alternatively to the conductor clamps, which pins can in particular also be inserted axially into the winding carrier and subsequently connected to one another and / or to the conductor clamps to form the winding. It is also possible for different linear pins to have insulation layers of different thicknesses.However, linear pins are preferably used only in the area of the winding connections, which means that they preferably have an insulation layer of the same thickness as those conductor clamps that have the thicker insulation layers.

[0028] Alternatively or in addition to the use of additional linear pins, individual slot feedthroughs can also be realized by separating at least one coupling section of at least one of the conductor clamps after the conductor clamps have been inserted into the winding support and in particular after the free ends have been connected in order to provide two winding connections.

[0029] Further advantages and details of the invention will become apparent from the following exemplary embodiments and the accompanying drawings. These schematically show: Fig. 1 and 2 show sectional detailed views of an embodiment of an electrical machine according to the invention, the windings of which can be produced by an embodiment of the method according to the invention, Fig. 3 and 4 show detailed views of a conductor of a winding of the Fig. 1 and 2 shown electrical machine, Fig. 5 a winding diagram for a winding of a further embodiment of an electrical machine according to the invention, and Fig. 6 an embodiment of a motor vehicle according to the invention.

[0030] Fig. 1 shows a sectional detailed view of a stator 1 of an electrical machine. The stator 1 comprises a winding support 2 with teeth 3 projecting from the winding support and slots 5 located therebetween. The slots 5 accommodate windings 4 of the electrical machine, which are formed by a respective conductor. Fig. 1various groove sections 14, 15 of the conductor are shown. As schematically shown by the different edge thicknesses of the groove sections 14, 15, the insulation layers of these groove sections 14, 15, as will be explained later with reference to Figs. 3 and 4 will be explained in more detail, have different layer thicknesses.

[0031] The windings 4 are, as in Fig. 2 is shown schematically, formed by several conductor clamps 6, 7, each having two groove sections 8 and a coupling section 13 connecting the groove sections 8. In Fig. 2 The solid conductor clamps 6 form the windings of a first phase and the dashed conductor clamps 7 form the windings of a second phase. For reasons of clarity, Fig. 2only two phases and only one respective winding layer are shown. Typically, windings for three phases are used in stators of electrical machines, and it is also possible to provide multiple parallel windings for individual phases.

[0032] During the production of the stator 1, the conductor clamps 6, 7 of the different phases are first arranged in a ring and then axially, i.e. in the vertical direction of the Fig. 2 , inserted into the winding support 2. The free ends 9, 10 of the conductor clamps 6, 7 are initially straight, so that a simple axial insertion into the winding support is possible. The individual conductor clamps 6, 7 are slightly inclined relative to the radius of the winding support 2, so that, for example, the free end 10 of the conductor clamp 6 is in a lower winding level, i.e. in Fig. 2 further away from the viewer than the free end 9.

[0033] To connect the individual conductor clamps 6, 7 to the windings 4, the free ends 9, 10 are twisted or bent. This is also referred to as twisting. Here, all free ends that lie on a certain radius are bent in the same direction. Thus, for example, the ends 10 located at a lower winding level are Fig. 2 to the left and the ends 9 located in a higher winding level are bent to the right. Thus, they overlap with another free end of an adjacent conductor clamp of an adjacent winding level in the connection area 11 and can be conductively connected, in particular welded, to one another.

[0034] The procedure described corresponds to the known procedure for manufacturing stators in a hairpin design. For this reason, it has only been briefly explained above using a highly simplified example. It is essential that the conductors of the various windings 4 intersect at a plurality of crossing points 12 in a stator 1 constructed in a hairpin design. At these crossing points, conductors with large voltage differences are guided close to one another, particularly in the area of the winding connections of the individual windings. It is therefore necessary to provide relatively thick insulation layers on the conductors, particularly in the area of the winding connections. Further away from the winding connections, the voltage drop between conductors of different phases intersecting at the crossing points 12 is typically considerably lower, so that insulation layers with thinner layer thicknesses can be used there.In order to achieve an optimal copper fill factor, it is advantageous, as shown in . Fig. 1 schematically shown, to provide insulation layers with different layer thicknesses for different groove sections 8, 14, 15. This will be explained in more detail below with reference to Figs. 3 and 4 explained.

[0035] Fig. 3 shows a detailed view of the groove section 14 and Fig. 4 A detailed view of the groove section 15. Both groove sections 14, 15 are formed by applying an insulating layer 17 to the conductor 16. The insulating layer 17 can be applied, in particular, as part of a plastic extrusion process, since such a process allows the layer thickness 25, 26 of the respective insulating layer 17 to be selected essentially freely.

[0036] As can be seen by comparing the Figs. 3 and 4As can easily be seen, the layer thickness 25 of the insulation layer 17 for the groove section 14 is considerably thinner than the layer thickness 25 of the insulation layer 17 for the groove section 15. The groove section 15 can thus be used particularly in areas where there are intersections with conductors of other phases with a large expected voltage difference. If no large voltage differences are expected at intersection points 12, groove sections 14 with a smaller layer thickness 25 of the insulation layer 17 can be used.

[0037] Despite the different layer thicknesses 25, 26 of the insulation layers 17, the sum of the cross-sectional areas of the conductor 16 and the insulation layer 17 is the same for both slot sections 14, 15, since the total width 18 and the total height 19 of the conductor 16 with the insulation layer 17 applied thereto are the same in both cases. Due to the identical dimensions 18, 19 of the conductor sections 14, 15 and thus in particular of the conductor clamps 6, 7 forming the corresponding conductor sections 14, 15, the slot sections 14, 15 and the conductor clamps 6, 7 can be easily handled during automated production of the stator 1, since the same devices can be used in the same way to handle slot sections 14, 15 and conductor clamps 6, 7 with different layer thicknesses 25, 26 of the insulation layer 17.

[0038] A simple way to achieve different layer thicknesses 25, 26 of the insulation layer 17 for different groove sections 14, 15 is to use conductor clamps 6, 7 whose groove sections 8 both have the same layer thickness 25, 26 of the insulation layer 17, whereby different layer thicknesses 25, 26 of the insulation layer 17 can be used for different conductor clamps 6, 7. The insulation layer 17 can extend essentially over the entire length of the conductor clamps 6, 7. In the area of the connections 11, this can either be removed as part of the connection or the conductor clamps 6, 7 can already be provided with insulation-free ends. This ensures, in particular, that a corresponding layer thickness 25, 26 of the insulation layer 17 is also present in the area of the crossing points 12.

[0039] The advantages of using insulation layers with different thicknesses for different sections of the winding of an electrical machine are explained below with reference to Fig. 5 explained using a specific example winding diagram. The winding diagram 20 shows the structure of a winding in a stator with a total of 52 slots 21. The boxes 24 each mark a winding layer in a slot 21 for one phase. The slots and winding layers for the remaining two phases are shown in Fig. 5Not shown for reasons of clarity. The boxes marked with the numbers 1 to 72 indicate the slot sections of a winding, with the slot sections being counted along the conductor. The winding is thus contacted at the winding terminals 27, 28. The remaining empty boxes 24 accommodate a second winding of the same phase, which is not shown for reasons of clarity. The letters A to H designate the individual winding layers of the slots 21. The arrows shown next to them indicate the direction in which free ends of slot sections of this winding layer are bent during twisting in order to connect them to other free ends.

[0040] The winding shown runs from box 1, which can be arranged close to the bottom of a slot, for example, initially, as shown by the dashed line, to slot bushings located relatively high up in the slots, namely box 23. From there, the winding is led back to the area of the slot bottoms, namely to box 72, as shown by the solid lines. The shape of the connecting lines 22, 23 shows how the respective slot sections are connected. The diagonally running lines 22 show a connection via a coupling section 13 of a respective conductor clamp 6, 7. The stepped lines 23 show a connection via bent ends 9, 10 of different conductor clamps 6, 7 via a connecting area 11, for example via a weld.It can be seen here that boxes 1 and 72, i.e., the slot sections that provide the winding connections 27, 28, are not connected to other slot sections via a coupling section 13. The corresponding slot sections can be inserted separately as pins. However, it is particularly advantageous to initially use a common conductor clamp for the slot sections associated with boxes 1, 72 and to separate their coupling section 13 after insertion into the winding support 2.

[0041] As already explained above, at crossing points 12 where conductors of different phases cross, high voltages between the crossing conductors are to be expected, especially if these crossing points 12 are located relatively close to the winding terminals 27, 28 for at least one of these conductors along the corresponding conductor. The conductor should therefore have a stronger insulation for a certain length starting from these winding terminals 27, 28, as described in Fig. 5by the thicker edges of boxes 1 to 5 and 66 to 72. This can be implemented relatively easily by using conductor clamps 6, 7 with different thicknesses of insulation layers, as explained above, which, however, preferably have the same external dimensions. Such conductor clamps with a thicker insulation layer can be used for box pairs 2 and 3, 4 and 5, 70 and 71, 68 and 69 and 66 and 67. In addition, such a conductor clamp can be used for box pair 1 and 72 and the coupling section 13 of this conductor clamp 6, 7 can then be separated, as explained above. For the remaining slot sections or boxes 6 to 65, however, conductor clamps 6, 7 with a thinner insulation layer 17 can be used in order to achieve an overall high copper fill factor of the slots 5.

[0042] Due to the high filling factors that can be achieved for slots and due to the potentially usable higher voltages, the described procedure is particularly relevant when using electrical machines 26 in motor vehicles 25, as is the case in Fig. 6 The electric machine 26 has a rotor 27 and the stator 1 already discussed above. The electric machine 26 can be used, for example, to drive the motor vehicle 25. The described procedure makes it possible to achieve high power densities with a compact design of the electric machine 26.

Claims

1. Electrical machine having a winding support (2) having multiple grooves (5, 21), which carries at least one winding (4), wherein the winding (4) is formed by a conductor (16) which has multiple groove sections (8, 14, 15) which each extend within one of the grooves (5, 21) of the winding support (2) and which are conductively connected by connecting sections of the conductor (16) which are outside the grooves (5, 21), wherein the winding (4) comprises multiple conductor clamps (6, 7) which are conductively connected to one another and which each form two groove sections (8, 14, 15) and a coupling section (13) connecting the groove sections (8, 14, 15), wherein the individual conductor clamps (6, 7) are inclined with respect to the radius of the winding support (2) in such a way that a first free end (10) of the respective conductor clamp (6) lies in a lower winding level than a second free end (9) of the conductor clamp (6), characterized in that the conductor (16) has at least in the groove sections (8, 14, 15) an insulation layer (17) applied to the conductor (16), wherein the insulation layer (17) has layer thicknesses (25, 26) different from one another for at least two of the groove sections (8, 14, 15), wherein both groove sections (14) of a first of the conductor clamps (6, 7) have an insulation layer (17) having a first layer thickness (25) and wherein both groove sections (15) of a second of the conductor clamps (6, 7) have an insulation layer (17) having a second layer thickness (26) different from the first layer thickness (25).

2. Electrical machine according to claim 1, characterized in that the sum of the cross-sectional areas of the conductor (16) and the insulation layer (17) in a first of the groove sections (8, 14, 15) is equal to the sum of the cross-sectional areas of the conductor (16) and the insulation layer (17) in a second of the groove sections (8, 14, 15), in which the insulation layer (17) has a different layer thickness (25, 26) than in the first groove section (8, 14, 15).

3. Electrical machine according to claim 1 or 2, characterized in that the first and second conductor clamps (6, 7) have the same external dimensions (18, 19).

4. Electrical machine according to any of the preceding claims, characterized in that the groove sections (8, 14, 15) each have either a first layer thickness (25) or a second layer thickness (26).

5. Electrical machine according to any of the preceding claims, characterized in that the conductor (16) of the winding (4) extends from a first to a second winding terminal (27, 28), wherein when counting the groove sections (8, 14, 15) along the conductor (16) starting from the first and / or the second winding terminal (27, 28), the insulation layer (17) of at least the first and / or the second and / or the third groove section (14) has an insulation layer (17) which has a greater layer thickness (26) than the insulation layer (17) of at least one groove section (15) along the conductor farther away from the first and / or second winding terminal (27, 28).

6. Electrical machine according to any of the preceding claims, characterized in that the insulation layer (17) is formed by a plastic sheath of the conductor (16).

7. Motor vehicle, characterized in that it comprises an electrical machine (26) according to any one of the preceding claims.

8. Method for producing a winding (4) for an electrical machine (26), comprising the steps: - providing a winding support (2) having multiple grooves (5, 21) and multiple conductor clamps (6, 7), which are each formed from a clamp-shaped conductor section and which each form two groove sections (8, 14, 15) and a coupling section (13) connecting the groove sections (8, 14, 15), wherein the conductor sections at least partially, namely at least in the groove sections (8, 14, 15), have an insulation layer (17) applied to the conductor section, wherein the insulation layers (17) of at least two conductor clamps (6, 7) have different layer thicknesses (25, 26), so that both groove sections (14) of a first of the conductor clamps (6, 7) have an insulation layer (17) with a first layer thickness (25) and both groove sections (15) of a second of the conductor clamps (6, 7) have an insulation layer (17) with a second layer thickness (26) different from the first layer thickness (25), - axially inserting the conductor clamps (6, 7) into the winding support (2) in such a way that the individual conductor clamps (6, 7) are inclined with respect to the radius of the winding support (2) in such a way that a first free end (10) of the respective conductor clamp (6) lies in a lower winding level than a second free end (9) of the conductor clamp (6), and that the groove sections (8, 14, 15) each extend within one of the grooves (5, 21) of the winding support (2), and - connecting free ends (9, 10) of a respective group of the conductor clamps (6, 7) to connect the conductor sections of these conductor clamps (6, 7) to a conductor (16) of a winding (4), whereby the groove sections (8, 14, 15) are conductively connected by connecting sections of the conductor (16) which are outside the grooves (5, 21).