Stator assembly for electric motors and manufacturing method

Abstract

This invention relates to a stator assembly for an electric motor, comprising a lamination assembly having a plurality of receiving recesses, each recess for receiving at least one conductor element of a stator winding within a conductor channel. Each receiving recess provides at least one flow channel for coolant extending along the conductor channel for cooling the conductor element. The lamination assembly includes a plurality of axially arranged lamination units, each providing an axial recessed section of the receiving recess. The recessed sections belonging to the lamination units have variations in recess geometry, which are derived from a group of at least two different recess geometry variations, such that the receiving recesses each have at least two different recess geometry variations along their axial orientation in the lamination assembly. The invention also relates to a corresponding manufacturing method.

Description

Technical Field

[0001] This invention relates to a stator assembly for an electric motor and a method for manufacturing such a stator assembly. The stator assembly includes at least one lamination assembly having a plurality of receiving recesses, each recess for receiving at least one conductor element of a stator winding in a conductor channel. Each of these receiving recesses provides at least one flow channel for coolant extending along the conductor channel for cooling the conductor element. Background Technology

[0002] This stator assembly provides effective heat dissipation because the conductor elements of the stator windings (also known as pins or hairpins) can be cooled directly. However, it is crucial that the conductor elements do not tilt or slip during assembly, thereby partially or even completely obstructing the flow channels. This blockage of the flow cross-section leads, in particular, to a significant increase in the pressure loss of the coolant flow and, overall, to undesirable limitations on cooling effectiveness.

[0003] Therefore, DE 10 2018 112 347 A1 describes an electric machine in which spacers are partially applied to the insulation of a conductor element, these spacers partially defining coolant channels for direct cooling of the conductor element. The spacers prevent blockage of the flow channels. Summary of the Invention

[0004] In contrast, the object of the present invention is to further improve the protection against blockage of flow channels due to conductor elements not positioned as intended. This reliable protection, which can be achieved simultaneously with low cost in terms of structure and manufacturing technology, has been particularly preferred.

[0005] This objective is achieved by a stator device according to the invention and by a method according to the invention. Preferred improvements of the invention are obtained from preferred embodiments. Other advantages of the invention are apparent from the summary and description of embodiments.

[0006] The stator assembly according to the invention is configured for use in an electric motor and includes a lamination assembly having a plurality of receiving grooves. These receiving grooves are respectively for receiving at least one conductor element of the stator winding. Each of these receiving grooves includes at least one conductor channel that can at least partially receive at least one conductor element of the stator winding. Each of these receiving grooves provides at least one flow channel for coolant, extending along the conductor channel of the at least one conductor element, for cooling the conductor element. The lamination assembly here includes a plurality of axially arranged lamination units. Each lamination unit here provides an axial groove section of the receiving groove. The groove section belonging to the lamination unit here has at least a partial groove geometry variation, which is taken from a group consisting of at least two different groove geometry variations. Here, these receiving grooves each have at least two different groove geometry variations in their (correspondingly) axial orientation along the lamination assembly. At least two different groove geometry variations are particularly present in the lamination assembly. Therefore, the lamination units of the lamination assembly particularly belong to one of these at least two groove geometry variations.

[0007] The stator assembly according to the invention offers numerous advantages. The modular construction, consisting of lamination units with different groove geometry variations, provides significant advantages. This allows for targeted different or variable groove geometries and, for example, flow redirection along the axial direction of the receiving groove. Furthermore, this allows for targeted resistance to flow channel blockage via inclined conductor elements or the inclination itself. It is also particularly advantageous that the desired geometry of the receiving groove can be formed in a particularly cost-effective manner by strategically arranging lamination units with different groove geometry variations in sequence. Therefore, the invention enables particularly rapid and economical manufacturing of stator assemblies for electric machines.

[0008] The groove geometry variations preferably differ from each other in the arrangement of their flow channels relative to their conductor channels. These groove geometry variations differ in particular in that the flow channels are arranged clockwise in front of or behind the conductor channel. In other words, these groove geometry variations differ in particular in that the flow channels are arranged to the left or right of the conductor channel relative to the radially inward to radially outward viewing direction. Thus, in a particular lamination unit, the flow channel is arranged, for example, clockwise in front of the conductor channel or to the left of the conductor channel. In another particular (especially adjacent) lamination unit, the flow channel is reversed and therefore arranged, for example, clockwise behind the conductor channel or to the right of the conductor channel. This results in a flow channel that jumps from one side to the other (and then returns again, etc.) or an alternating lateral flow channel.

[0009] It is also possible, and preferably, that the variations in groove geometry differ from one another in that the flow channels are arranged radially above or radially below the conductor channels. This results in a flow channel orientation that jumps from top to bottom (and then returns again, etc.). This orientation of the flow channels can also be referred to as a radially alternating orientation.

[0010] In all design schemes, it is particularly preferred and advantageous that the flow channel extends clockwise in front of or behind the conductor channel and simultaneously radially above or below the conductor channel. This generally produces a spiral or helical orientation of the flow channel. The flow channel is particularly spirally wound around the conductor channel. In all design schemes, the direction of rotation can be clockwise or counterclockwise. Therefore, a right-handed spiral (clockwise rotating flow channel orientation) or a left-handed spiral (counterclockwise rotating flow channel orientation) can be provided. Thus, a general orientation is formed, for example, the flow channel moving downwards from the left and then jumping to the right and then upwards and then jumping back to the left, etc. In another example, the flow channel can be provided moving downwards from the right and then jumping to the left and then upwards and then jumping back to the right, etc. This design scheme provides a particularly effective and low-cost possibility for preventing blockage of the flow cross-section and simultaneously provides a very advantageous coolant flow.

[0011] In a preferred and advantageous design, the conductor channel is bounded by the wall of the receiving groove on at least two sides (extending in the axial direction). Here, the flow channel is particularly bounded by the wall of the receiving groove on at least two sides (extending in the axial direction). Preferably, the conductor channel and the flow channel are abutted to each other on at least two sides (extending in the axial direction). Variations in the groove geometry particularly concern which sides the conductor channel and the flow channel are abutted to each other. It can be additionally or alternatively suggested that variations in the groove geometry differ in which side the wall of the receiving groove bounds the conductor channel and the flow channel. Variations in the groove geometry particularly concern which side the conductor element abuts against the wall of the receiving groove. The conductor element abuts against different sections of the wall of the receiving groove, particularly according to the groove geometry variation.

[0012] Preferably, the stacked unit cells with different groove geometry variations are axially arranged such that each flow channel extends spirally within the receiving groove around the conductor channel (and preferably also around the conductor element that can be received therein). Preferably, the stacked unit cells with different groove geometry variations are axially arranged such that the conductor element alternately abuts against the wall of the receiving groove with at least one different side.

[0013] Of particular preference among all design options is that adjacent stacked units have different variations in groove geometry.

[0014] Preferably, at least two of the at least two groove geometry variations are formed by mounting at least two lamination units in the lamination assembly with their orientation rotated 180° relative to each other. The lamination units here have the same geometry design, at least relative to the receiving groove. The lamination units can also be identical. This rotation allows for the formation of variable groove geometries in a particularly cost-effective manner, as it eliminates the need to pre-plan or manufacture different lamination units. The axis particularly represents this rotation transverse to the rotation axis of the electric motor and / or transverse to the longitudinal axis or axial extension of the stator assembly.

[0015] Preferably and advantageously, the flow channel accommodating the groove can be positioned either in front of or behind the conductor channel accommodating the groove in a clockwise direction (or relative to the viewing direction from the radial interior to the radial exterior) by flipping the stacked unit by 180°. This flipping, in particular, changes the flow channel from one longitudinal side of the conductor channel to the other longitudinal side.

[0016] Equally preferred and advantageous is the formation of at least two of the at least two variations of the groove geometry by mounting at least two stacked unit cells, which are geometrically different, within the stacked unit assembly. The difference between the stacked unit cells lies particularly in their receiving grooves. The difference between the stacked unit cells depends particularly on whether they are flipped. The receiving grooves of such stacked unit cells cannot be geometrically consistent by flipping.

[0017] In a favorable design, it is proposed that, depending on the variation in groove geometry, the flow channel accommodating the groove is arranged radially inside or radially outside the conductor channel accommodating the groove. Specifically, the transformation of the flow channel from radially inside to radially outside is achieved by axially arranging the stacked unit cells having these different groove geometry variations.

[0018] Preferred and advantageous in all design schemes is that the group consisting of groove geometry variations includes at least four different groove geometry variations. In particular, the groove geometry variations are formed by mounting at least two geometrically different stacked unit cells in the stacked unit assembly, and these differently constructed stacked unit cells are also mounted in the stacked unit assembly with at least 180° rotation respectively. This specifically achieves that the receiving groove has at least four different groove geometry variations along its direction through the stacked unit assembly. At least four different groove geometry variations are particularly present in the stacked unit assembly. The stacked unit assembly preferably includes a plurality of stacked unit cells (e.g., at least eight or at least twelve or more), each stacked unit cell having at least one of the four different groove geometry variations.

[0019] Preferably, these laminated unit groups, which are mounted with their components rotated 180° relative to each other, are arranged axially adjacent in pairs. Laminated unit groups with different geometric configurations are preferably arranged axially adjacent in pairs. In particular, laminated unit groups with different geometric configurations are arranged with laminated unit groups rotated 180° between them.

[0020] Particularly preferably, the at least four different groove geometry variations are arranged in a repeating order in the stack assembly.

[0021] For example, a stacked unit having a first geometry is followed by a stacked unit of the same (first) geometry, flipped 180°. Immediately following is, for example, a stacked unit having a second geometry. Subsequent stacked units, especially those of the same (second) geometry, flipped 180°. This sequence is preferably repeated to form a stacked unit with the first geometry again.

[0022] It is possible and advantageous that the four different groove geometry variations are combined with each other to secure the conductor elements in a form-locking manner along the stack assembly in a total of four directions. The conductor elements are specifically secured in a form-locking manner to the front and rear, as well as radially above and below, of the conductor channel in a clockwise direction (or relative to the viewing direction from radially inward to radially outward). The conductor elements can here be supported on the walls accommodating the grooves and / or on adjacent conductor elements.

[0023] Preferably, the flow channel is formed by four axially adjacent lamination units with different groove geometry variations, forming at least one helical winding around the conductor channel. The four adjacent groove geometry variations are particularly combined with each other to form the helical winding of the flow channel.

[0024] The applicant reserves the right to claim protection for an electric machine having a stator assembly according to the invention. This electric machine also particularly advantageously solves the aforementioned problems. The electric machine is particularly configured for use in the powertrain of electric or hybrid vehicles. The electric machine may include at least one rotor rotatable relative to the stator assembly and / or other electric machine components.

[0025] Within the scope of this invention, the descriptions of axial and radial directions particularly relate to the rotational axis and / or longitudinal axis of the electric machine. The term "radial outer" may also be referred to as the yoke side, and the term "radial inner" may also be referred to as the head side.

[0026] The flow channel is specifically defined by the position of the conductor element in the receiving groove. The flow channel corresponds particularly (only) to the free space in the receiving groove not occupied by the conductor element. The conductor channel corresponds particularly to the space in the receiving groove occupied by the conductor element. The stator assembly may include at least one stator winding having at least one conductor element and preferably having multiple conductor elements.

[0027] The laminated unit particularly comprises multiple laminates. Within the scope of the invention, the laminated assembly is also understood to be composed of solid and, for example, integral laminated units. The differences among these groove geometry variations lie particularly in the groove geometry of the groove section used to receive the groove. The groove geometry particularly relates to the cross-sectional geometry of the section receiving the groove.

[0028] The receiving groove extends at least partially through the lamination assembly, particularly in the axial direction. The conductor channel or conductor element extends at least partially through the lamination assembly, particularly in the axial direction, and preferably through the receiving groove. In particular, the conductor channel, and especially the flow channel, also extends at least partially along the conductor element. The conductor channel extends particularly parallel to the conductor element.

[0029] The flow path and the conductor path are particularly adjacent to each other and also particularly adjacent to the conductor element. The flow path is particularly adjacent to the conductor path on only two (especially adjacent) sides. The conductor path is particularly adjacent to the flow path on only two (especially adjacent) sides.

[0030] The method according to the invention is used to manufacture a stator assembly. The method is particularly designed to enable the manufacture of the stator assembly described above. Here, lamination units are axially arranged and oriented relative to each other by rotation about an axially extending axis of rotation such that the axial groove sections of each lamination unit overlap each other, the overlap being at least 75% and preferably at least 90% of the maximum possible overlap. The maximum possible overlap is particularly preferred. It is also possible that the axial groove sections of each lamination unit are offset relative to each other, the offset being at most 25% and preferably at most 10% of the minimum possible offset. The minimum possible offset is particularly preferred. The lamination units are oriented relative to each other such that at least 75% and preferably at least 90% of the maximum possible continuous groove cross-sectional area exists along the receiving groove and / or there exists the largest continuous receiving groove (or the largest groove opening). The groove sections of each lamination unit are oriented flush with each other, particularly in terms of their axial cross-sectional openings.

[0031] The conductor elements are then arranged in receiving grooves. The lamination units are then rotated about an axially extending axis of rotation and oriented so that the axial groove sections of each lamination unit are offset relative to each other, and the conductor elements are secured in the receiving grooves by this offset (particularly by clamping). These lamination units are then secured, preferably in a manner to prevent further axial rotation. This securing is achieved, in particular, by form-fitting and / or force-fitting and / or material-fitting. The stator device according to the invention is particularly configured to be manufactured according to this method.

[0032] Other advantages of the invention are derived from the embodiments, which will be described below with reference to the accompanying drawings.

[0033] In the attached diagram:

[0034] Figure 1 A schematic illustration of the height of the stator assembly according to the invention is shown in a cross-sectional perspective view from a slightly lower angle.

[0035] Figure 2 It shows according to Figure 1 A highly schematic detail illustration of the geometry variation of the first groove of the stator assembly;

[0036] Figure 3 It shows according to Figure 1 A highly schematic detail illustration of the geometric variation of the second groove of the stator assembly;

[0037] Figure 4 It shows according to Figure 1 A highly schematic detail illustration of the geometric variation of the third groove of the stator assembly;

[0038] Figure 5 It shows according to Figure 1 A highly schematic detail illustration of the geometric variation of the fourth groove of the stator assembly; and

[0039] Figure 6 A schematic diagram of the height of the stator device according to the invention is shown in a perspective view from the oblique front, with a simplified flow direction.

[0040] Figure 1 A stator assembly 1 according to the invention is partially shown for use in an electric motor 10 (not shown in detail herein). The stator assembly 1 is manufactured herein by a method according to the invention. The electric motor 10 can, for example, be configured as an electric motor for the powertrain of an electric vehicle or a hybrid vehicle.

[0041] The stator assembly 1 here includes a lamination assembly 2 having a plurality of axially arranged lamination assembly units 12. The number of lamination assembly units 12 here is merely exemplary and may be increased or decreased depending on the construction specifications of the machine 10. The lamination assembly unit 12 may be composed of individual laminations or discs or may be constructed as a solid. Each lamination assembly unit 12 here is provided with an axial groove section 33 for receiving a groove 3.

[0042] The stator assembly 1 here includes a stator winding 11 having a plurality of electrical conductor elements 4 in contact with each other, these conductor elements being, for example, implemented as copper pins. The conductor elements 4 here extend in groups in receiving grooves 3. The receiving grooves 3 extend axially through the lamination assembly 2 and are distributed (uniformly) and spaced apart in the circumferential direction of the lamination assembly.

[0043] To achieve particularly effective cooling of the stator assembly 1, the conductor element 4 is cooled directly. For this purpose, coolant flows through a flow channel 23 extending within each receiving recess 3. The flow channel 23 is defined by the position of the conductor element 4 within the receiving recess 3. The flow channel 23 corresponds to the space within the receiving recess 3 not occupied by the conductor element 4. The corresponding space occupied by the conductor element 4 within the receiving recess 3 is defined as the conductor channel 13. Therefore, the receiving recess 3 is divided into the conductor channel 13 and the flow channel 23.

[0044] The receiving groove 3 surrounds the conductor channel 13 and the flow channel 23 with a wall 43. Here, the wall 43 is interrupted radially inside the lamination assembly 2. Therefore, when manufacturing the stator assembly 1, the conductor element 4 can be assembled into the receiving groove 3 in a particularly low-cost manner. However, an embodiment with a circumferentially closed wall 43 is also possible.

[0045] The stack assembly 2 here has four different groove geometry variations 5, 15, 25, and 35. Depending on the groove geometry variations 5, 15, 25, and 35, the conductor channel 13 and the flow channel 23 are positioned differently in the receiving groove 3.

[0046] The stacked unit 12 here belongs to one of the groove geometry variants 5, 15, 25, and 35, respectively. For better illustration of the arrangement, the four groove geometry variants 5, 15, 25, and 35 are shown in... Figure 4 The four different groove geometry variations, 5, 15, 25, and 35, are numbered. It is thus clear that they are arranged in a repeating order.

[0047] exist Figures 2 to 5 The various groove geometry variations 5, 15, 25, and 35 are shown in more detail here. Figure 2A first groove geometry variant 5 is shown, wherein the flow channel 23 is oriented in the receiving groove 3 to the radial right (clockwise in front of the conductor channel 13) and radially upward. Figure 3 A second groove geometry variant 15 is shown, wherein the flow channel 23 is arranged in the receiving groove 3 radially to the left (clockwise rear of the conductor channel 13) and radially upward.

[0048] These two groove geometry variations 5 and 15 are implemented here by stacked unit 12 with the same construction. For the second groove geometry variation 15, the corresponding stacked unit 12 is flipped 180° and then arranged in the stacked assembly 2.

[0049] Figure 4 A third groove geometry variant 25 is shown, in which the flow channel 23 is arranged radially to the left and radially downward in the receiving groove 3. Figure 5 The fourth groove geometry variant 35 is shown. The flow channel 23 is arranged radially to the right and radially downward in the receiving groove 3. The third and fourth groove geometry variants 25 and 35 are also implemented here by the same stacked assembly unit 2 constructed in terms of geometry, one of which is rotated 180° and mounted in the stacked assembly 2.

[0050] The stacked unit 12 described above is as follows: Figure 1 The arrangement shown forms a spiral path of flow channels 23 around each associated conductor channel 13. Figure 6 The resulting flow path is simplified. For clarity, only the conductor element 4 of the stator assembly 1 is shown here. The receiving groove 3, not shown here, extends along the conductor element 4 with its conductor channel 13 and flow channel 23. The simplified flow path shows how the flow channel 23 wraps around the conductor element 4 housed in the conductor channel 13.

[0051] During exemplary manufacturing, each stack unit 12 is arranged or rotated before the conductor element 4 is pushed in, such that the largest possible recess or hole is present on the entire stack assembly 2, or the largest possible recess area is obtained.

[0052] The conductor element 4 is now assembled into the receiving groove 3, and after the conductor element 4 is introduced, the individual lamination unit 12 is rotated. Thus, the individual conductor element 4 is fixed within the receiving groove 3. The conductor element 4 rests against the lamination unit wall in the circumferential direction. Because the lamination unit 12 rests against the conductor element 4, and thus generates a force in the circumferential direction, the conductor element 4 is clearly and reliably fixed in its position.

[0053] In the current rotational position, the lamination units 12 are then secured to each other so that they can no longer be reversed relative to each other. This can be achieved by welding the stator back or inserting locating pins axially, or by gluing the lamination units 12 together or by threading the individual lamination units 12 together. This ensures simplified assemblability and, according to this design (shape-locking), prevents the conductor elements from tilting in the receiving recesses.

[0054] The invention presented herein effectively prevents the flow channel 23 from becoming blocked due to the conductor element 4 not being oriented as desired and, for example, tilting. Through the arrangement of the different groove geometry variations 5, 15, 25, 35 shown herein, the conductor element 4 is generally form-locked along the lamination assembly 2 in four directions. The flow cross-section of the flow channel 23 is reliably kept open. This fixation of the conductor element 4 in the receiving groove 3 can be achieved with particularly low cost in terms of structure and manufacturing technology by using the respective lamination assembly units 12 which provide the corresponding groove geometry variations 5, 15, 25, 35.

[0055] List of reference numerals in the attached diagram:

[0056] 1. Stator assembly 15. Groove geometry variant

[0057] 2. Stacked assembly 23. Flow channel

[0058] 3. Receiving groove 25. Groove geometry variations.

[0059] 4 Conductor element 33 Groove section

[0060] 5 Groove Geometry Variations 35 Groove Geometry Variations

[0061] 10 Machines 43 Walls

[0062] 11 Stator windings

[0063] 12-piece stack unit

[0064] 13 Conductor Channels

Claims

1. A stator assembly (1) for an electric motor (10), the stator assembly comprising a lamination assembly (2) having a plurality of receiving grooves (3) for receiving at least one conductor element (4) of a stator winding (11) in a conductor channel (13), wherein each of the receiving grooves (3) provides at least one flow channel (23) for coolant extending along the conductor channel (13) of the at least one conductor element (4) for cooling the conductor element (4). Its features are, The lamination assembly (2) includes a plurality of axially arranged lamination units (12), each lamination unit providing an axial groove segment (33) for receiving grooves (3), and each groove segment (33) belonging to the lamination unit (12) having at least a partial groove geometry variant (5, 15, 25, 35), the groove geometry variant being derived from a group of at least two different groove geometry variants (5, 15, 25, 35), such that the receiving grooves (3) each have at least two different groove geometry variants (5, 15, 25, 35) along their axial orientation in the lamination assembly (2). These stacked unit units (12) having these different groove geometry variations (5, 15, 25, 35) are axially arranged such that the flow channels (23) extend spirally around the conductor channel (13) in these receiving grooves (3).

2. The stator device (1) according to claim 1, wherein the variations in the geometry of these grooves (5, 15, 25, 35) differ from each other in the arrangement of their flow channels (23) relative to their conductor channels (13).

3. The stator device (1) according to claim 1 or 2, wherein the conductor channels (13) are defined on at least two sides by the walls (43) of the receiving groove (3), and wherein the flow channels (23) are defined on at least two sides by the walls (43) of the receiving groove (3), and wherein the conductor channels (13) and the flow channels (23) are adjacent to each other on at least two sides, and wherein the variations in the groove geometry (5, 15, 25, 35) differ from each other in which the conductor channels (13) and the flow channels (23) are adjacent to each other on which side.

4. The stator device (1) according to claim 1 or 2, wherein adjacent lamination units (12) have different groove geometry variations (5, 15, 25, 35).

5. The stator device (1) according to claim 1 or 2, wherein at least two groove geometry variations (5, 15, 25, 35) are formed by mounting at least two lamination units (12) in the lamination assembly (2) with the lamination units rotated 180° relative to each other.

6. The stator device (1) according to claim 5, wherein the flow channel (23) of the receiving groove (3) can be set in a clockwise direction to be in front of or behind the conductor channel (13) of the receiving groove (3) by rotating the lamination unit (12) by 180°.

7. The stator device (1) according to claim 1 or 2, wherein at least two groove geometry variations (5, 15, 25, 35) are formed by at least two lamination group units (12) that are geometrically different are mounted in the lamination group assembly (2).

8. The stator device (1) according to claim 7, wherein, depending on the groove geometry variant (5, 15, 25, 35), the flow channel (23) receiving the groove (3) is arranged radially inside or radially outside the conductor channel (13) receiving the groove (3).

9. The stator device (1) according to claim 1 or 2, wherein the group consisting of groove geometry variants (5, 15, 25, 35) comprises at least four different groove geometry variants (5, 15, 25, 35) formed by at least two lamination group units (12) that are geometrically different are mounted in the lamination group assembly (2), and these differently constructed lamination group units (12) are also mounted in the lamination group assembly (2) by at least 180° rotation respectively.

10. The stator device (1) according to claim 9, wherein the lamination units (12) mounted with 180° rotation relative to each other are arranged axially adjacent in pairs, and wherein the lamination units (12) which are geometrically different are also arranged axially adjacent in pairs.

11. The stator assembly (1) according to claim 9 or 10, wherein the four different groove geometry variations (5, 15, 25, 35) are arranged in a repeating order in the lamination assembly (2).

12. The stator device (1) according to claim 9 or 10, wherein the four different groove geometry variations (5, 15, 25, 35) are combined with each other to secure the conductor elements (4) in a form-locking manner in a total of four directions along the lamination assembly (2).

13. The stator device (1) according to claim 9 or 10, wherein the flow channel (23) is formed by four axially adjacent lamination units (12) with different groove geometry variations (5, 15, 25, 35) forming a helical winding around the conductor channel (13).

14. A method for manufacturing a stator device (1) according to any one of the preceding claims, wherein the lamination units (12) are axially arranged and oriented to each other by rotation about an axially extending axis of rotation such that the axial groove sections (33) of each lamination unit (12) overlap each other to the greatest possible extent, and wherein the conductor elements (4) are then arranged in the receiving grooves (3), and wherein the lamination units (12) are then oriented to each other by rotation about an axially extending axis of rotation such that the axial groove sections (33) of each lamination unit (12) are offset relative to each other, by which the conductor elements (4) are secured in the receiving grooves (3).

15. The method of claim 14, wherein the stacked unit (12) is then fixed in a manner to prevent further axial rotation.

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