Stator for an electric machine having a strip-shaped winding unit for a stator winding and method for producing the same

Abstract

The invention relates to a stator (10) for an electric machine, the stator comprising a stator core (11) and a stator winding (20), wherein the stator core (11) has a plurality of slots spaced apart in the circumferential direction and having a depth extending in the radial direction, and the stator core allows slot segments (3) of the stator winding (20) to be arranged in a plurality of radially spaced apart radial positions (RP), wherein the stator (10) has a strip-shaped winding unit (1, 1', 1", 1"', 1"") (20), the strip-shaped winding unit comprising A first winding conductor and a second winding conductor (2, 2'), wherein the two winding conductors extend in a first layer and a second layer (L1, L2) of a winding unit (1, 1', 1", 1"', 1""), and the two winding conductors each comprise: a. a plurality of straight slot segments (3) extending in a transverse direction (Q) of the winding unit (1, 1', 1", 1"', 1"") and arranged parallel to each other, b. a plurality of first curved end segments (5), each of which has a first curved end segment (6) extending in a first direction (Q) of the winding unit (1, 1', 1", 1"', 1""), and b. a plurality of first curved end segments (5), each of which has a first curved end segment (7) extending in a first direction (Q) of the winding unit (1, 1', 1", 1"', 1""), and b. a plurality of first curved end segments (5), each of which has a first curved end segment (6) extending in a first direction (Q) of the winding unit (1, 1', 1", 1""), and b. a plurality of first curved end segments (5), each of which has a first curved end segment (7) extending in a first direction (Q) of the winding unit (1, 1 The invention relates to a method for manufacturing a plurality of second curved end sections (6), wherein the first curved end section comprises a plurality of first curved end sections and a second curved end section, wherein the first curved end section comprises a plurality of second curved end sections and a plurality of second curved end sections, ... 5, 6) each interconnects a slot segment (3) of an associated winding conductor (2, 2') located in a first layer (L1) and a slot segment (3) of an associated winding conductor located in a second layer (L2), wherein the first slot segment (3) is arranged at a first radial position in the first slot, and the second slot segment (3) directly connected to the first slot segment (3) via a first end segment (5) is arranged at a second radial position in the second slot, and the second radial position is offset by two radial positions relative to the first radial position.

Description

Technical Field

[0001] The invention relates to a stator having a strip-shaped winding unit for stator winding, the strip-shaped winding unit having a first winding conductor and a second winding conductor, wherein both winding conductors are guided in a first layer and a second layer of the winding unit. The invention also relates to a winding method for such a stator. Background Art

[0002] Strip winding units are used, for example, to produce strip-wave windings in electric machines and enable efficient production of large numbers of such machines. Strip winding units are usually prefabricated and correspond to parts of the stator winding to be produced. The prefabricated winding units are usually inserted individually into the slots of the stator core, and these prefabricated winding units are interconnected after introduction to form the stator winding.

[0003] Examples of such winding units are known from US 8,779,643 B2, US 7,386,931 B2, US 7,269,888 B2 and US 7,365,467 B2. These strip-shaped winding units include a plurality of slot segments extending straightly in the transverse direction of the winding unit and arranged parallel to each other. These straight slot segments can then be introduced into the slots of the stator core to form the stator winding. The winding unit also includes: a plurality of first curved end segments, each of which interconnects two slot segments and is arranged on a first longitudinal side of the winding unit; and a plurality of second curved end segments, each of which interconnects two slot segments and is arranged on a second longitudinal side of the winding unit opposite to the first longitudinal side. With the aid of these curved end segments, a wavy course of the winding conductor can be obtained. Due to this geometry, the winding with this type of winding unit is also called a wave winding.

[0004] Known winding units are usually very long, so that the winding unit extends several times around the circumference of the stator. This is associated with high production costs. Another disadvantage of known winding units is that they usually have a large number of layers, which makes further processing more difficult, in particular making it more difficult to introduce the winding unit into the stator core. Summary of the invention

[0005] Against this background, the aim arises to reduce the amount of work involved in the manufacture of electric machines.

[0006] The strip-shaped winding unit for stator winding according to the invention comprises a first winding conductor and a second winding conductor, both of which are guided in a first layer and a second layer of the winding unit. In this context, the first layer and the second layer are to be understood as respective vertical positions of the winding conductors, which are produced when the strip-shaped winding unit is positioned on a horizontal plane and thus outside the stator. Both winding conductors comprise: a plurality of slot segments extending straight in the transverse direction of the winding unit, the plurality of slot segments being arranged parallel to each other; and a plurality of first curved end segments, each of which interconnects two slot segments of the associated winding conductor and is arranged on a first longitudinal side of the winding unit; and a plurality of second curved end segments, each of which interconnects two slot segments of the associated winding conductor and is arranged on a second longitudinal side of the winding unit opposite to the first longitudinal side.

[0007] A particular feature of the winding unit according to the invention is that the first curved end section and the second curved end section each interconnect a slot section of the associated winding conductor located in the first layer and a slot section of the associated winding conductor located in the second layer. When the strip-shaped winding unit is arranged on a horizontal plane, the first curved end section and the second curved end section each connect a slot section of a lower layer with a slot section of an upper layer.

[0008] In connection with the present invention it is important not to confuse layers with the radial position of slot segments in the stator slots. Layers essentially define the vertical position of slot segments of a strip-like winding unit outside the stator when the winding unit extends vertically in a horizontal plane. After the strip-like winding unit is introduced into the stator, the original layers of slot segments are shifted to radial positions which depend not only on the previous layers but also on the arrangement of the winding unit relative to any other strip-like winding units arranged in the stator. After the strip-like winding unit is inserted into the stator core, the slot segments of a particular layer, e.g. the first layer of a strip-like winding unit, may therefore assume different radial positions in the slots.

[0009] Since the slot sections extending in the transverse direction in the strip-shaped winding unit are each arranged in only one of two layers, a strip-shaped winding unit with a small thickness, in particular a thickness of only two layers, is produced. This results in the winding unit being able to be introduced into the slots of the stator core with less effort.

[0010] The stator for the electric machine according to the present invention further comprises a stator core and a stator winding, wherein the stator core has a plurality of slots spaced apart in the circumferential direction, the plurality of slots having a depth extending in the radial direction and enabling slot segments of the stator winding to be arranged in a plurality of radially spaced radial positions, wherein the stator winding has a strip-shaped winding unit as described above. The slot segments of the strip-shaped winding unit are preferably received in the slots of the stator core in such a manner that the strip-shaped winding unit is arranged in a spiral shape in the stator core.

[0011] In one embodiment of the strip winding unit, two winding conductors are interconnected at the reversal point via a third curved end segment to form a so-called reverse winding. The third curved end segment differs from the first end segment and the second end segment in that the third curved end segment does not only interconnect the slot segments of different layers. Instead, the corresponding slot segments of the first winding conductor and the second winding conductor located in the first layer or the corresponding slot segments of the first winding conductor and the second winding conductor located in the second layer are interconnected via the third curved end segment. Therefore, this reverse winding only includes the first curved end segment and the second curved end segment as curved end segments, each of which interconnects the slot segments of different layers and interconnects exactly one curved end segment of the slot segments of the same layer - the third curved end segment. The third curved end segment is located at the reversal point of the reverse winding.

[0012] In this context, it should also be pointed out again that the third curved end section can well interconnect slot segments of different radial positions. Crucially, the third curved end section connects slot segments in the same layer of the strip-shaped winding unit when the strip-shaped winding unit is arranged to be vertically spread out on a horizontal plane outside the stator.

[0013] The formation of the reverse point of the winding conductor enables the winding unit to have two winding connection parts, which are arranged on the same longitudinal side of the strip-shaped winding unit and in the same layer of the winding unit. When the winding unit is arranged in the stator core, these winding connection parts can be arranged on the same end face of the stator core and arranged to be either both radially inward or both radially outward, thereby reducing the amount of work for contacting the winding connection parts.

[0014] In the context of the present invention, a straight slot segment is understood to mean a straight segment of a winding cable which can be introduced into a slot of a stator core to form a stator winding.Such slot segments are preferably spaced apart parallel to each other at the same distance.

[0015] In the context of the present invention, a curved end segment is an end segment that does not extend straight. The end segment can reverse the winding conductor by substantially 180°. The curved end segment can have an arc curvature and / or a bending point. For example, the curved end segment can include a first substantially straight sub-segment and a second substantially straight sub-segment interconnected via a bending point. By interconnecting such a curved end segment with a slot segment in a first layer and a slot segment in a second layer, preferably, the first straight sub-segment is arranged in the first layer and the second straight sub-segment is arranged in the second layer, thereby achieving a position change at the bending point within the winding unit.

[0016] The fact that the strip-shaped winding units are preferably arranged in the stator core in a spiral manner means, with regard to an embodiment of the winding units without reverse winding, that the individual slot segments of the winding units are received in different radial positions in the slots of the stator core, the first radial position of the first slot segment being radially further away than the second radial position of the second slot segment, the first slot segment being at a greater distance from one end of the associated winding conductor, and the second slot segment being at a smaller distance from one end of the associated winding conductor.

[0017] The third radial position of the third slot segment is preferably located radially more inwardly than the second radial position, wherein the third slot segment is at an even smaller distance from the reversal point or the respective end of the winding conductor than the second slot segment. In this respect, the individual slot segments of the winding unit are received at different radial positions in the slots of the stator core, so that the radial position of the slot segments is arranged radially more inwardly as the distance from the reversal point of the winding unit or the end of the respective winding conductor decreases.

[0018] The stator core of the stator is preferably designed as a laminated core.

[0019] In the stator according to the invention, it is further provided that a first slot segment is arranged in a first radial position in the first slot, and a second slot segment directly connected to the first slot segment via a first end segment is arranged in a second radial position in the second slot, the second radial position being offset by two radial positions relative to the first radial position. In this respect, there is an offset of two radial positions between two adjacent slot segments of the same winding cable. This enables an intermediate radial position offset by one radial position from the first radial position to be occupied by another slot segment of the same winding cable, for example by a slot segment of the same winding cable which is indirectly connected to the first slot segment and the second slot segment via a reversal point if a reversal point is available.

[0020] In this context, it is advantageous if the third slot section is arranged in the first slot at a third radial position which is offset by one radial position from the first radial position and if the fourth slot section which is directly connected to the third slot section via the second end section is arranged in the second slot at a fourth radial position which is identical to the third radial position. By taking up radial positions in this way, it is possible to achieve a collision-free passage of the forward section of the winding cable and the return section of the winding cable through the reversal point if a reversal winding is provided.

[0021] According to an advantageous embodiment, it is provided that the fifth slot segment, which is directly connected to the second slot segment via the second end segment, is arranged in the third slot at a fifth radial position, which is identical to the second radial position. In this respect, there is initially an offset of two radial positions between the first slot segment and the second slot segment of the same winding cable, and there is no offset between the second slot segment and the fifth slot segment. It is preferably provided that the sixth slot segment, which is directly connected to the fifth slot segment via the first end segment, is arranged in the fourth slot at a sixth radial position, which is offset by two radial positions relative to the second radial position or the fifth radial position. In this respect, there is initially an offset of two radial positions between the first slot segment and the second slot segment of the same winding cable, there is no offset between the second slot segment and the fifth slot segment, and there is an offset of two radial positions between the fifth slot segment and the sixth slot segment.

[0022] An alternative advantageous embodiment provides that the first groove segment is arranged in the first groove at a first radial position, and the second groove segment directly connected to the first groove segment via the second end segment is arranged in the second groove at a second radial position, which is offset by two radial positions relative to the first radial position, the third groove segment is arranged in the first groove at a third radial position, which is offset by one radial position from the first radial position, and the fourth groove segment directly connected to the third groove segment via the first end segment is arranged in the second groove at a fourth radial position, which is the same as the third radial position.

[0023] In this context, it is advantageous that the fifth slot segment, which is directly connected to the second slot segment via the first end segment, is arranged in the third slot at a fifth radial position, which is the same as the second radial position. As discussed above in conjunction with the first alternative, there is initially an offset of two radial positions between the first slot segment and the second slot segment of the same winding cable, and there is no offset between the second slot segment and the fifth slot segment. It is preferably provided that the sixth slot segment, which is directly connected to the fifth slot segment via the second end segment, is arranged in the fourth slot at a sixth radial position, which is offset by two radial positions from the second radial position or the fifth radial position. In this regard, there is initially an offset of two radial positions between the first slot segment and the second slot segment of the same winding cable, there is no offset between the second slot segment and the fifth slot segment, and there is an offset of two radial positions between the fifth slot segment and the sixth slot segment.

[0024] According to an advantageous embodiment of the invention, the first winding conductor has two connecting sections, which are either both arranged on the first longitudinal side or both arranged on the second longitudinal side. The winding conductors of the winding units can be contacted via the connecting sections. The arrangement of the connecting sections on the same side facilitates contacting of the connecting sections, in particular facilitating contacting of the connecting sections of the first strip-shaped winding unit with the connecting sections of the second strip-shaped winding unit.

[0025] In this context, it is advantageous if the connection segments are either both arranged in the first layer or both arranged in the second layer. By arranging the connection segments in the same layer, it becomes possible that the connection segments can all be arranged radially on the outside when the winding units are arranged in the stator core. This can reduce the amount of work involved in making contact with the connection segments. Alternatively, the connection segments can all be arranged radially on the inside of the stator core. As a further alternative, the first of the two connection segments can be arranged in the first layer and the second of the two connection segments can be arranged in the second layer.

[0026] A preferred embodiment of the present invention provides that the winding unit comprises one or more additional winding conductors, which are identical to the first winding conductor and the second winding conductor and are offset in the following manner: the first winding conductor, the second winding conductor and the additional winding conductor are arranged in the same first and second layers of the winding unit, and the slot segments of the first winding conductor, the second winding conductor and the additional winding conductor are arranged to be spaced apart from each other in the slots of the stator. The slot segments of the additional winding conductor are arranged to be offset relative to the slot segments of the first winding conductor and the second winding conductor. Thus, a winding unit with a small thickness of only two layers having multiple winding cables can be obtained. Such a winding unit with multiple winding cables will also be referred to as a winding pad below. The slot segments of the winding conductors of such a winding pad are stacked in pairs and laterally spaced apart from each other, except for the slot segments arranged in the edge region, which correspond to the spaced stator slots. The winding cables of the winding unit can be optionally interconnected in series or in parallel. For this purpose, the connecting section of the first winding conductor, the connecting section of the second winding conductor and the connecting section of one or more further winding conductors are preferably interconnected in a suitable manner. For example, as described above, the first winding conductor and the second winding conductor can be interconnected to form a reverse winding at the reverse point. Using a further 16 winding conductors, two of which are always connected to form a reverse winding, a winding pad with a total of 9 reverse windings can be produced, which can be offset by one slot pitch relative to each other in the longitudinal direction. Therefore, all winding conductors are also distributed on the first layer and the second layer of the winding unit here.

[0027] However, of course, different winding conductors can also be interconnected to form a winding mat without being connected in pairs at the reversal points. Various configurations using series and / or parallel connections can be envisaged here to best adapt the winding mat to the operating requirements of the motor.

[0028] In another embodiment of the present invention, the stator includes at least one additional winding unit, which is identical to the winding unit described above and is arranged to be offset relative to the winding unit described above in the circumferential direction of the stator. The winding unit and the additional winding unit thus form two winding pads. One of the winding pads is attached to a first slot on the inner circumference of the stator, and the other winding pad is attached to a second slot on the inner circumference of the stator, wherein the first slot and the second slot are different. For example, if the first winding pad is now guided on the second slot, the second slot is occupied by both the two conductors of the first winding pad and the two conductors of the second winding pad. In other words, in this configuration, the slot segment arranged on the outer edge of the additional winding unit is arranged in the second slot, and the additional slot segment of the additional winding unit connected to the outer edge of the additional winding unit via the first curved end segment or the second curved end segment is arranged in the third slot. As a result, the first slot section of the first winding mat is arranged in the first slot at a first radial position, and the second slot section directly connected to the first slot section via the first end section is arranged in the second slot at a second radial position, which is opposite to the first radial position and offset by two radial positions. Here, the third slot section of the first winding mat is arranged in the first slot at a third radial position, which is offset by one radial position from the first radial position, and the fourth slot section directly connected to the third slot section via the second end section is arranged in the second slot at a fourth radial position, which is the same as the third radial position.

[0029] Furthermore, the object is achieved by a winding method for a stator of an electric machine, in which the following method steps are carried out:

[0030] First, at least one first winding unit and at least one second winding unit are produced, each of which has at least a first winding conductor and a second winding conductor. The first winding conductor and the second winding conductor are produced in a manner such that they are guided in the first layer and the second layer of the corresponding winding unit. The winding conductors are designed so that each of the winding conductors has a plurality of slot sections, which extend straightly in the transverse direction of the winding unit and are arranged parallel to each other. In addition, a plurality of first curved end sections are produced, each of which interconnects the two slots of the associated winding conductor and is arranged on the first longitudinal side of the winding unit. In addition, a plurality of second curved end sections are produced, each of which interconnects the two slots of the associated winding conductor and is arranged on the second longitudinal side of the winding unit opposite to the first longitudinal side.

[0031] The slot segments of the first winding unit are arranged in a plurality of slots of the stator core spaced apart in the circumferential direction. The slot segments of the second winding unit are also arranged in a plurality of slots of the stator core spaced apart in the circumferential direction. This is accomplished in the following manner: the second winding unit is offset in the interior of the stator relative to the first winding unit in the circumferential direction, and the slot segments of the first winding unit and the second winding unit are arranged in the same slots. The offset can be designed so that: within each of the strip-shaped winding units, the first slot segment is arranged in a first radial position in the first slot, and the second slot segment directly connected to the first slot segment via the first end segment is arranged in a second radial position in the second slot, and the second radial position is offset from the first radial position by two radial positions.

[0032] In order to introduce the first winding unit and the second winding unit into the substantially cylindrical stator, it is advantageous to apply the first winding unit and the second winding unit offset in the circumferential direction to a cylindrical drive mandrel. The drive mandrel can be moved axially into the interior space enclosed by the stator core. The winding units can then be extended radially outwards from the drive mandrel into the slots of the stator core. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Further details and advantages of the invention will be explained below with reference to the exemplary embodiments shown in the accompanying drawings. In the drawings:

[0034] Figure 1 A strip winding unit according to a first exemplary embodiment of the present invention is shown in a perspective view;

[0035] Figure 2 The side view shows the Figure 1 The winding unit;

[0036] Figure 3 A strip winding unit according to a second exemplary embodiment of the present invention is shown in a perspective view;

[0037] Figure 4 The longitudinal side view shows the Figure 3 The winding unit;

[0038] Figure 5 The side view shows the Figure 3 The winding unit;

[0039] Figure 6 A strip winding unit according to a third exemplary embodiment of the present invention is shown in a perspective view;

[0040] Figure 7 The longitudinal side view shows the Figure 6 The winding unit;

[0041] Figure 8The side view shows the Figure 6 The winding unit;

[0042] Fig. 9 A schematic cross-sectional view shows a first exemplary embodiment of the present invention having a Figure 3 A stator with a strip winding unit;

[0043] Fig.10 Shows the Fig. 9 The basis in the stator Figure 3 A diagram illustrating the arrangement of winding units;

[0044] Fig.11 The stator winding is shown in a circuit diagram;

[0045] Fig.12a and Figure 12b The arrangement in the stator core is shown in a perspective view and in a top view from the longitudinal side or the front side. Figure 3 The winding unit;

[0046] Fig.13a and Fig.13b A winding unit according to a fourth exemplary embodiment illustrating the arrangement in a stator core is shown in a perspective view and in a plan view from the longitudinal side or the front side;

[0047] Fig.14a and Fig.14b A winding unit according to a fifth exemplary embodiment illustrating the arrangement in a stator core is shown in a perspective view and in a plan view from the longitudinal side or the front side;

[0048] Fig.15a and Fig.15b A portion of a stator winding illustrating the arrangement in a stator core is shown in a perspective view and in a top view from the longitudinal side or front side;

[0049] Fig.16a and Fig.16b A stator winding illustrating the arrangement in the stator core is shown in a perspective view and in a top view from the longitudinal side or the front side,

[0050] Fig.17 shows a stator of an electric machine having four strip winding units,

[0051] Fig.18 shows a stator of an electric machine having two strip winding units,

[0052] Fig.19 The stator of an electric machine having two strip winding units is shown, each of which is designed as a counter-winding.

[0053] Fig. 20Another stator of an electric machine with four strip winding units is shown,

[0054] Figure 21 to Figure 23 shows the process steps for producing a spiral winding from two ribbon winding units according to an embodiment of the invention, and

[0055] Fig.24 The method steps for transferring a spiral winding into the slots of a stator are shown. DETAILED DESCRIPTION

[0056] Figure 1 and Figure 2 A strip-shaped winding unit 1 according to an exemplary embodiment of the present invention is shown, which has a first conductor 2 and a second conductor 2', which are guided in a first layer L1 and a second layer L2 of the winding unit 1. The start and end of the two winding conductors 2, 2' are each marked with an arrow for orientation. Both the conductors 2, 2' of the winding unit 1 include a plurality of slot segments 3, which extend straight along the transverse direction Q of the winding unit 1 and are arranged parallel to each other. The distance between the slot segments 3 of the winding conductors 2, 2' is dimensioned so that adjacent slot segments 3 can be introduced into different stator slots of the stator core of the motor. The slot segments 3 are interconnected via end segments 5, 6, which protrude from the stator core at the end when the slot segments 3 of the winding unit 1 are introduced into the stator slots of the stator core.

[0057] The slot segments 3 are interconnected on a first longitudinal side of the winding unit 1 via a plurality of first curved end segments 5. The first curved end segments 5 each interconnect a first slot segment 3 in the first layer L1 and a second slot segment 3 in the second layer L2 of the corresponding winding conductor 2, 2'. In this respect, a position change of the associated winding conductor 2, 2' is achieved by the first end segment 5. On a second longitudinal side of the winding unit 1 opposite to the first longitudinal side, a plurality of second curved end segments 6 are provided, which each interconnect two slot segments 3 and are arranged on the second longitudinal side of the winding unit 1 opposite to the first longitudinal side. All second curved end segments 6 interconnect the first slot segment 3 in the first layer L1 and the second slot segment 3 in the second layer L2 of the associated winding conductor 2, 2'. Initially, no current connection is provided between the two winding conductors 2, 2' within the winding unit. The beginning and end of the winding conductor 2, 2' can be used for any connection, in particular after a complete winding mat has been inserted. For example, a series connection or a parallel connection of the winding conductors 2 , 2 ′ is conceivable.

[0058] Figure 3 , Figure 4 and Figure 5A strip-shaped winding unit 1' according to an exemplary embodiment of the invention is shown, in which two winding conductors 2, 2' are interconnected at a reversal point via a third bent end section 6'. In this way, a so-called reversal winding is produced. The winding conductors 2, 2' are also guided in the first layer L1 and the second layer L2 of the winding unit 1', as can be seen in FIG. Figure 4 . The winding unit 1' in turn comprises a plurality of slot segments 3, which extend straight in the transverse direction Q of the winding unit 1 and are arranged parallel to one another. The distances between the slot segments 3 of the winding conductors 2, 2' are dimensioned so that adjacent slot segments 3 can be introduced into different stator slots of the stator core of the electric machine. The slot segments 3 are interconnected via end segments 5, 6, 6', which protrude from the stator core at the ends when the slot segments 3 of the winding unit 1 are introduced into the stator slots of the stator core.

[0059] The slot segments 3 are interconnected on the first longitudinal side of the winding unit 1' via a plurality of first curved end segments 5. The first curved end segments 5 each interconnect the first slot segments 3 in the first layer L1 and the second slot segments 3 in the second layer L2. In this respect, the first end segments 5 enable a position change of the corresponding winding conductors 2, 2' forming a reverse winding. A plurality of second curved end segments 6, 6' are provided on the second longitudinal side of the winding unit 1' opposite to the first longitudinal side, each of which interconnects two slot segments 3 and is arranged on the second longitudinal side of the winding unit 1' opposite to the first longitudinal side. Exactly one second curved end segment 6' is designed to form a reverse point of the winding conductor formed by the winding conductors 2, 2', so that this one second curved end segment connects the two slot segments 3 in the second layer L2 to each other, one of the two slot segments being assigned to the first winding conductor 2, and one slot segment being assigned to the second winding conductor 2'. However, all other second bent end sections 6 connect the first slot section 3 in the first layer L1 and the second slot section 3 in the second layer L2 of the first winding conductor 2 or the second winding conductor 2 ′.

[0060] According to a modification of this exemplary embodiment, provision can be made for a second curved end section 6 ′, which is provided for forming a reversal point, to interconnect two groove sections in the first layer.

[0061] The strip-shaped winding unit 1' thus has a forward conductor and a return conductor formed by two winding conductors 2, 2', which describe a wavy path from the first connecting section 4 to the reversal point. The conductor reverses at the reversal point and then describes a wavy path again from the reversal point to the second connecting section 4.

[0062] The bent end sections 5 , 6 , 6 ′ of the winding unit 1 ′ reverse the conductor by substantially 180°. The bent end sections 5 , 6 , 6 ′ each comprise a substantially straight first subsection 7 and a substantially straight second subsection 8 , which are interconnected via a bending point 9 .

[0063] The winding conductors 2, 2' also include two connecting sections 4, via which contact with the counterwinding formed in this way can be achieved. In the present exemplary embodiment, both connecting sections 4 are arranged on the second longitudinal side of the winding unit 1 and both are arranged in the same layer of the winding unit 1, here in the first layer L1.

[0064] Figure 6 , Figure 7 and Figure 8 The illustration shows a third exemplary embodiment of a strip-shaped winding unit 1", which differs from the winding unit 1' according to the second exemplary embodiment in that, in addition to the first winding conductor 2 and the second winding conductor 2', the strip-shaped winding unit also includes a plurality of other winding conductors 2". Here, too, the first winding conductor 2 and the second winding conductor 2' again form a reverse winding. In the same way, another reverse winding is formed by two further winding conductors 2".

[0065] Therefore, the other reverse winding is identical to the reverse winding formed by the first winding conductor and the second winding conductor. The other reverse winding is arranged offset in such a way that the winding conductors 2, 2' of the reverse winding and the winding conductors 2" of the other reverse winding are arranged in the same first layer L1 and the same second layer L2 of the winding unit 1". In this regard, the winding unit 1" forms a winding pad having a plurality of winding conductors 2, 2', 2", which can be contacted via a large number of connecting sections 4. The slot sections of these winding conductors 2, 2', 2" are arranged at intervals divided by the slots in the lateral direction.

[0066] The following will use Fig. 9 and Fig.10 The spiral arrangement of the strip-shaped winding unit 1' in the stator core 11 of the stator 10 according to the second exemplary embodiment is explained by the representation in FIG. The figure shows how the previously described layers of slot segments in the strip-shaped winding unit arranged on a horizontal plane and extending vertically on the horizontal plane are transferred into radial positions within the stator slots. For the sake of clarity, the stator 10 and the stator core 11 are only shown in FIG. Fig. 9 The lines extending in the radial direction correspond to individual slots of the stator core 11, which are arranged at a certain distance in the circumferential direction of the stator core 11. The stator slots have a depth in the radial direction that allows the winding unit 1' to be arranged in one of eight different radial positions. Fig.10Schematically, eight different radial positions RP on ten different slots N are shown, in which slot sections of winding conductors 2, 2' are arranged. The slot section 3 of the first winding conductor 2 is marked with reference numeral A in the region between the first connecting section 4 (outgoing) and the reversal point, while the slot section 3 of the second winding conductor 2' is marked with reference numeral B in the region between the reversal point and the second connecting section 4 (return). It can be seen that the two regions of the reversal winding formed by the winding conductors 2, 2', i.e. the forward winding conductor and the return winding conductor, are interwoven on two layers of the winding unit 1. Due to the spiral arrangement of the winding unit 1', the two layers now extend on eight radial positions of the slot N.

[0067] It can be seen that the first slot segment 3, A is arranged in the first slot N=10 at the first radial position RP=1, and the second slot segment 3, A directly connected to the first slot segment 3, A via the first end segment 5 is arranged in the second radial position RP=3 in the second slot N=19, and the second radial position RP=3 is offset by two radial positions from the first radial position RP=1. The third slot segment 3, B is arranged in the first slot N=10 at the third radial position RP=2, and the third radial position RP=2 is offset by one radial position from the first radial position RP=1, and the fourth slot segment 3, B directly connected to the third slot segment 3, B via the second end segment 6 is arranged in the second slot N=19 at the fourth radial position RP=2, and the fourth radial position RP=2 is the same as the third radial position RP=2. In addition, the fifth slot segment 3, A directly connected to the second slot segment 3, A via the second end segment 6 is arranged in the third slot N=28 at the fifth radial position RP=3, and the fifth radial position RP=3 is the same as the second radial position RP=3. This scheme continues until the reversal point is reached: the sixth slot segment 3, A connected to the fifth slot segment 3, A via the first end segment 5 is arranged in the fourth slot N=37 at a sixth radial position RP=5, which is offset by two radial positions compared to the fifth radial position RP=3. The seventh slot segment 3, A directly connected to the sixth slot segment 3, A via the second end segment 6 is arranged in the fifth slot N=46 at a seventh radial position RP=5, which is identical to the sixth radial position RP=5. The eighth slot segment 3, A connected to the seventh slot segment 3, A via the first end segment 5 is arranged in the sixth slot N=55 at an eighth radial position RP=7, which is offset by two radial positions compared to the seventh radial position RP=5. The ninth slot segment 3, A directly connected to the eighth slot segment 3, A via the second end segment 6 is arranged in the seventh slot N=64 at a ninth radial position RP=7, which is identical to the eighth radial position RP=7. Finally, the first end section 5 connects the ninth slot section 3, A in the seventh slot N=64 with the tenth slot section 3, A in the eighth slot N=73. The second end section 6' connects the tenth slot section 3, A with the eleventh slot section 3, B in the seventh slot N=73, wherein the eleventh slot section 3, B has a radial position RP=8, which is the same as the radial position N=8 of the tenth slot section 3, A.

[0068] Fig.11 The diagram in FIG. 1 shows by way of example the structure of a stator winding 20 from a plurality of strip-shaped winding units, wherein: Fig. 9 and Fig.10 The winding unit shown in FIG. 1 is denoted by reference numeral U1 - 1 .

[0069] exist Fig.12a and Figure 12b Again, the Figure 3 A strip-shaped winding unit 1' is shown, wherein the winding unit 1' is arranged in a spiral manner to illustrate the arrangement of the winding unit 1' in a stator core (not shown here). Fig.12a A perspective view of the stator is shown and Figure 12b A top view of a longitudinal side or front side of the stator is shown.The strip-shaped winding unit 1 ' has two connection regions 4 spaced apart at a distance which substantially corresponds to the distance between the slot regions 3 of the winding conductors 2, 2'.

[0070] Fig.13a and Fig.13b Shown according to Figure 3 A modification of a strip-shaped winding unit 1 ′, wherein the winding unit 1 ″′ is arranged in a spiral manner in order to illustrate the arrangement of the winding unit in a stator core (not shown here). Fig.13a A perspective view of the stator is shown and Fig.13b A top view of the longitudinal side or front side of the stator is shown. Fig.12a and Figure 12b , the strip-shaped winding unit 1 '' has two connection regions 4 spaced apart at a distance that is smaller than the distance between the slot regions 3 of the winding conductors 2 , 2 '.

[0071] Fig.14a and Fig.14b A winding unit 1 ″″ according to a fourth exemplary embodiment is shown. Fig.14a A perspective view of the stator is shown and Fig.14b A top view of the longitudinal side or front side of the stator is shown. The winding unit comprises a Fig.12a The winding unit 1' and according to Fig.13a The two winding units 1"' are each arranged offset so that a winding unit 1"" having two layers is obtained. The connecting sections 4 of the individual winding units 1', 1"' are connected in such a way that a series connection of the three winding units 1', 1"' is obtained. The winding unit 1"" is connected to the winding unit 1" according to Fig.11 corresponds to one phase of the stator.

[0072] Fig.15a and Fig.15b The illustration in shows a section 21 of a stator winding 20 to illustrate the arrangement in the stator core. Fig.15a A perspective view of the stator is shown and Fig.15b A top view of the longitudinal side or front side of the stator is shown. Section 21 comprises Fig.14a The winding units 1"" are arranged in each case offset.

[0073] Finally, according to Fig.11The stator winding 20 is shown in Fig.16a and Fig.16b middle. Fig.16a A perspective view of the stator is shown and Fig.16b A top view of the longitudinal side or front side of the stator is shown. The stator winding 20 comprises a Fig.15a The five identical parts 21 are each arranged to be offset by 72°.

[0074] Figures 17 to 20 A further embodiment of the invention is shown in which the formation of a reversal point between two winding conductors is partially omitted. This has the advantage of increasing the possibilities of parallel connection compared to the embodiment with a reversal point. For a spiral arrangement with reversal windings, a plurality of winding units can be used which are uniformly inserted on the circumference directly connected to the slot segments. This also results in a restriction of the connection options. Only a precise number of poles / 2 winding units can be used.

[0075] Especially for machines with higher power (>200 kW), the parallel connection of the winding units must be increasingly implemented.The end of the cable can be used in addition to the connection if it is generated instead of a reversal point.

[0076] When the winding units are evenly distributed on the circumference of the stator, the number of parallel branches is fixed. It is therefore desirable to be able to generate several parallel branches in which the number of winding units is less than in the case of even distribution.

[0077] If the reversal point is omitted, the end of the released cable can be used as an additional connection point for a parallel connection. Fig. 9 When the individual winding units are arranged spirally, a symmetrical winding can be produced again.

[0078] A variable number of winding units is generated by inserting a number of individual winding units in the stator that is less than the number of poles / 2. The slots in the individual pole regions do not have the beginning of any cables. Here the slot base is filled with the winding unit inserted in the preceding slot section. This results in a significantly greater number of connection options, which means that the motor can be better adapted to the voltage conditions when necessary.

[0079] Described below Figures 17 to 20 An embodiment of a stator with strip-shaped winding units is shown in FIG.

[0080] exist Figures 17 to 20, the beginning of the cable and the end of the cable of the respective strip-shaped winding units are provided with uniform reference numerals. Thus, in each of the exemplary embodiments, the beginning of the cable of the first conductor is provided with reference numeral 30, and the end of the cable of the first conductor is provided with reference numeral 31. The beginning of the cable of the second conductor is indicated by reference numeral 32, and the end of the cable of the second conductor is indicated by reference numeral 33. The beginning of the cable of the third conductor is provided with reference numeral 34, and the end of the cable is provided with reference numeral 35. The beginning of the cable of the fourth conductor is provided with reference numeral 36. The end of the cable of the fourth conductor is provided with reference numeral 37. The beginning of the cable of the fifth conductor is indicated by reference numeral 38. The end of the cable of the fifth conductor is indicated by reference numeral 39. The beginning of the cable of the sixth conductor is indicated by reference numeral 40. The end of the cable of the sixth conductor is indicated by reference numeral 41. The beginning of the cable of the seventh conductor is indicated by reference numeral 42. The end of the cable of the seventh conductor is indicated by reference numeral 43. The beginning of the cable of the eighth conductor is denoted by reference numeral 44. The end of the cable of the eighth conductor is denoted by reference numeral 45.

[0081] Fig.17 A stator 10 of an electric machine is shown, which has a starter core 11 and four strip winding units inserted into the slots in the stator core. The winding is designed for the stator to have 72 slots and 8 poles, with 6 conductors in each slot. The number of holes is therefore 3. For clarity, only one slot conductor is shown for each pole. The first winding unit includes a first conductor having a starting end 30 of a cable and an end 31 of a cable, and a second conductor having a starting end 32 of a cable and an end 33 of a cable. The slot section of the second conductor is located in a first radial position in the first slot 50, which is arranged on the slot base. The starting end 32 of the cable of the second conductor is also connected to the slot section. The slot section of the first conductor is positioned adjacent to the slot section in the radial direction. Relative to each other, the slot section of the first conductor is located in a first layer, which is arranged above the slot section of the second conductor (hereinafter referred to as the second layer). Here, the lower layer means a layer that, viewed from the slot base, is arranged below the respective other conductor, which by definition is located in the upper layer. It can be seen that the slot segments of the second conductor are arranged in the second slot 51 above the slot segments of the first layer. In the third slot 52, the conditions are reversed again. That is, the layer of the slot segments of the first conductor is again located above the layer of the slot segments of the second conductor. This change of position continues until the end 31 of the cable of the first conductor is reached.

[0082] The slot section of the second conductor positioned at the slot base in the first slot 50 is connected via an end section not shown to a slot section in the second slot 51 positioned at a radial position shifted by two radial positions compared to the radial position at the slot base in the first slot 50. The slot section of the second conductor in the second slot 51 is connected via another end section not shown to a slot section in the third slot 52 at a radial position corresponding to the slot section of the second conductor in the second slot 51. The slot section of the second conductor located in the third slot 52 is connected via an end section not shown to a slot section in the fourth slot 53 at a radial position shifted by two radial positions from the slot section of the second conductor in the third slot 52.

[0083] The radial position of the first conductor between the first slot 50 and the fifth slot 54 follows a similar path. From the first slot 50 to the second slot 51, the radial position of the slot section of the first conductor does not change. Instead, the radial position changes by two radial positions between the second slot 51 and the third slot 52. From the third slot 52 to the fourth slot 53, the radial position again remains unchanged. From the fourth slot 53 to the fifth slot 54, the radial position again shifts by two positions.

[0084] The above-described arrangement of the slot segments of the conductors of the winding units relative to each other with respect to the layers of the slot segments and with respect to the radial position of the slot segments in the slots of the stator is also found in the other winding units. Here again, the second winding unit is characterized in a simplified manner by a third conductor having a cable start 34 and a cable end 35 and a fourth conductor having a cable start 36 and a cable end 37. The third winding unit comprises a fifth conductor having a cable start 38 and a cable end 39 and a sixth conductor having a cable start 40 and a cable end 41. The fourth winding unit comprises a seventh conductor having a cable start 41 and a cable end 42 and an eighth conductor having a cable start 43 and a cable end 44.

[0085] The winding thus consists of evenly distributed winding elements which are inserted into directly connected slot sections. Figure 3 to Figure 1 The change compared to the embodiment of 6 is that the reversal point is omitted and the end of the released cable can be used for further connection. The eight cables shown can be connected in parallel. Balancing currents are avoided by the symmetrical structure.

[0086] Fig.18The stator of the motor with two strip winding units is shown. A stator winding configuration with 10 poles and 3 holes can be seen, here with 90 slots. There are 8 conductors in each of these slots. For the sake of clarity, only two conductors in only two winding units and the beginning of their corresponding cables and the end of the cables are shown. Therefore, there are a total of 4 cable beginnings 30, 32, 34, 36 and 4 cable ends 31, 33, 35, 37. In the figure, only 4 slots in total show the beginning of the cable. This means that 4 windings are connected in parallel. The remaining slots are filled with slot sections belonging to the beginning of the cable. The winding units are placed asymmetrically in the stator to concentrate the beginning of the cable on a section of the stator. The connecting elements can therefore be arranged in a locally concentrated manner, and mass production is simplified. A slight asymmetry occurs, which does not necessarily lead to an increased balancing current.

[0087] The first winding unit comprises a first conductor having a cable start 30 and a cable end 31 and a second conductor having a cable start 32 and a cable end 33. The second winding unit comprises a third conductor having a cable start 34 and a cable end 35 and a fourth conductor having a cable start 36 and a cable end 37. In this embodiment, it is also found that the combination Fig.17 The pattern of the route of the relevant layer and the radial position of the slot segments involved are described. The relative position change between the slot segments of the strip winding unit occurs in each slot, in which two slot segments of the same strip winding unit are arranged, and the adjacent slot segments of the conductor are offset by two radial positions or not offset radial positions only when the radial position of the entire strip winding unit changes. This situation occurs, for example, in the slot where the beginning of the cable is located.

[0088] Fig.19 The stator of the electric machine is shown with two strip winding units, each of which is designed as a counter-winding. A first conductor with a cable start 30 forms a traveling wave that ends at the cable end 31. A second conductor with a cable start 32 forms a counter-traveling wave that ends at the cable end 33. The first conductor and the second conductor together form a strip winding unit.

[0089] To form the reversal point, the end 31 of the cable of the first conductor and the beginning 32 of the cable of the second conductor are interconnected by a bent end portion, which is not shown in the figure. This can be a separate connection, for example, a galvanic connection is established between the first conductor and the second conductor via a weld or a soldering point. However, it is also possible to design the first conductor and the second conductor as an integral cable, which is already shaped in such a way before being inserted into the stator slots to form the forward wave and the reverse traveling wave.

[0090] In a similar manner, the second strip winding unit with a reversal point is formed by a third conductor having a cable start 34 and a cable end 35 and a fourth conductor having a cable start 36 and a cable end 37. The reversal point is located between the end 35 of the cable of the third conductor and the start 36 of the cable of the fourth conductor, as in the case of the first winding pad of the present embodiment, the reversal point is located on the side of the winding head facing the air gap. This can be a separate connection, for example, establishing a current connection between the third conductor and the fourth conductor via a weld or a weld. However, the third conductor and the fourth conductor can also be designed as an integral cable, which has been shaped so as to form a forward wave and a reverse traveling wave before being inserted into the stator slot.

[0091] Fig. 20 Another stator of an electric machine with four strip winding units is shown. The stator consists of 90 slots forming 10 poles. Here, too, there are 8 conductors in a slot. Here, 4 winding units with 8 cable starts 30, 32, 34, 36, 38, 40, 42, 44 are used. This means that 8 windings can be connected in parallel. Not every pole has a cable start 30, 32, 34, 36, 38, 40, 42, 44. This configuration can only be realized in this arrangement, because such a parallel connection can neither be realized by the number of holes (q=3) nor by the number of poles 10.

[0092] Figure 21 to Figure 23 The method steps for producing a spiral winding from two strip-shaped winding units according to an embodiment of the invention are shown. A transmission tool is shown in the form of a transmission mandrel 14, which is used to transfer the stator winding into the stator core.

[0093] As an example, Figure 21 to Figure 24 The application of a first winding unit 12 and a second winding unit 13 on a drive spindle is shown, wherein for the sake of clarity, the two winding units 12, 13 are here only represented by a first winding unit 2 and a second winding unit 2'. The winding conductors 2, 2' can each have a cable start and a cable end, or alternatively, the winding conductors can be connected via a reversal point to form a reversal winding, so that each of the winding units 12, 13 has only half of the winding connection, as in a winding without a reversal point.

[0094] As can be seen, the winding units 12 , 13 are introduced into the grooves of the drive spindle in a manner offset in the circumferential direction of the drive spindle. Fig.21 The winding units 12, 13 in the first slot section are initially still flat in the lateral shape when they are arranged in the slot of the drive mandrel 14. After the first slot section of the corresponding winding unit is fixed in the slot, the drive mandrel 14 is rotated counterclockwise (see Fig. 22). As a result, the strip-shaped winding units 12, 13 begin to undergo a spiral deformation, which eventually continues when the drive mandrel 14 rotates further. In this case, all slot sections of the winding units 12, 13 are pulled into the slots of the drive mandrel 14 one after another.

[0095] In some of the slots of the drive spindle 14, the slot sections of the first winding unit 12 overlap with the slot sections of the second winding unit 13 - this can be seen in Fig.23 This overlap leads to the already mentioned course of radial positions of the groove sections in the grooves.

[0096] The winding units 12, 13 applied to the drive mandrel in this way are then introduced into the inwardly open slots of the stator. For this purpose, the drive mandrel 14 equipped with the winding units 12, 13 is first inserted axially into the cylindrical interior of the stator. The slot sections are then radially expanded out of the slots in the drive mandrel 14 into the slots in the stator. The method steps are as follows: Fig.24 It is shown by way of example.

[0097] The exemplary embodiments described above should not be understood as limiting. Winding units according to the invention with a different number of conductors and stators according to the invention with a different number of slots, a different number of pole pairs and a different slot factor can be produced. In particular, the number of radial positions is not limited to eight, but can be less, for example four, five or six, or can be more, for example nine or ten. Furthermore, the number of slots is not limited to three, but can deviate from this, for example the number of slots can be two or four. The number of pole pairs and / or the number of phases can also take values ​​different from the values ​​shown.

[0098] Description of Reference Numerals

[0099] 10 Torque transmission device. 1, 1', 1", 1"', 1"" winding unit 2, 2', 2" winding conductor 3, A, B slot segment 4 connecting segment 5 first end segment 6, 6' second end segment 7 first subsegment 8 second subsegment 9 bending point 10 stator 11 stator core 12 first winding unit 13 second winding unit 14 drive spindle 20 stator winding 21 part of stator winding 30 beginning of cable of first conductor 31 end of cable of first conductor 32 beginning of cable of second conductor 33 end of cable of second conductor 34 beginning of cable of third conductor 35 End of the cable of the third conductor 36 Start of the cable of the fourth conductor 37 End of the cable of the fourth conductor 38 Start of the cable of the fifth conductor 39 End of the cable of the fifth conductor 40 Start of the cable of the sixth conductor 41 End of the cable of the sixth conductor 42 Start of the cable of the seventh conductor 43 End of the cable of the seventh conductor 44 Start of the cable of the eighth conductor 45 End of the cable of the eighth conductor 50 First slot 51 Second slot 52 Third slot 53 Fourth slot 54 Fifth slot L1, L2 Layer N of winding unit Slot Q Transverse direction RP Radial position

Claims

1. A stator (10) for an electric machine, the stator having a stator core (11) and a stator winding (20), the stator core (11) having a plurality of slots spaced apart in the circumferential direction and having a depth extending in the radial direction, and the arrangement structure of the slot segments (3) allows the stator winding (20) to be located in a plurality of radially spaced apart radial positions (RP), the stator (10) having a strip-shaped winding unit (1, 1', 1", 1"', 1"'), the strip-shaped winding unit having a first winding conductor and a second winding conductor (2, 2'), both of which extend in a first layer and a second layer (L1, L2) of the winding unit (1, 1', 1", 1"', 1""), and each of the winding conductors comprises: a. a plurality of slot segments (3), the plurality of slot segments extending straightly along the transverse direction (Q) of the winding unit (1, 1', 1", 1"', 1"") and arranged parallel to each other, b. a plurality of first bent end sections (5), each of which interconnects two slot sections (3) of the associated winding conductor and is arranged on a first longitudinal side of the winding unit (1, 1', 1", 1"', 1""), c. a plurality of second curved end sections (6), each of which interconnects two slot sections (3) of the associated winding conductor and is arranged on a second longitudinal side of the winding unit (1, 1', 1", 1"', 1"") opposite to the first longitudinal side, d. a first curved end section and a second curved end section (5, 6) each interconnecting a slot section (3) of an associated winding conductor (2, 2') located in the first layer (L1) and a slot section (3) of an associated winding conductor located in the second layer (L2), e. The first slot section (3) is arranged at a first radial position in the first slot, and the second slot section (3) directly connected to the first slot section (3) via a first curved end section (5) is arranged at a second radial position in the second slot, and the second radial position is offset from the first radial position by two radial positions; the third slot section (3) is arranged at a third radial position in the first slot, and the third radial position is offset from the first radial position by one radial position, and the fourth slot section (3) directly connected to the third slot section (3) via a second curved end section (6) is arranged at a fourth radial position in the second slot, and the fourth radial position is the same as the third radial position.

2. The stator (10) according to claim 1, wherein: A fifth slot segment (3) directly connected to the second slot segment (3) via a second curved end segment (6) is arranged in the third slot at a fifth radial position, which is identical to the second radial position.

3. The stator (10) according to claim 2, wherein: The two winding conductors (2, 2') are connected to the reverse winding at a reverse point via a third bent end section (6'), wherein either i. a slot section (3) of each of the first winding conductor and the second winding conductor (2, 2') located in the first layer (L1), or ii. One slot section (3) of each of the first winding conductor and the second winding conductor (2, 2') located in the second layer (L2) The interconnection is via said third curved end section (6').

4. The stator (10) according to claim 3 has two connecting sections (4) for a counter-winding formed by two interconnected winding conductors (2, 2'), wherein the connecting sections are either both arranged on the first longitudinal side or both arranged on the second longitudinal side.

5. The stator (10) according to claim 4, wherein: The connecting sections (4) are either both arranged in the first layer (L1) or both arranged in the second layer (L2).

6. The stator (10) according to claim 5, wherein: The winding unit (1, 1', 1", 1"', 1"") comprises one or more additional winding conductors (2"), which are designed to be identical to the first winding conductor and the second winding conductor (2, 2') and are offset in such a way that the first winding conductor, the second winding conductor and the additional winding conductor (2, 2', 2") are arranged in the same first layer and the second layer (L1, L2) of the winding unit (1, 1', 1", 1"', 1""), and that the slot sections (3) of the first winding conductor, the second winding conductor and the additional winding conductor are arranged at a distance from each other in the slots of the stator.

7. The stator (10) according to claim 6 has another winding unit designed identically to the winding unit (1, 1', 1", 1"', 1"") according to claim 6 and arranged offset relative to the winding unit in the circumferential direction of the stator.

8. The stator (10) according to claim 7, wherein: The slot segment (3) arranged on the outer edge of the further winding unit is arranged in the second slot, and the further slot segment (3) of the further winding unit connected to the outer edge of the further winding unit via the first bent end segment or the second bent end segment (6) is arranged in the third slot.

9. The stator (10) according to claim 1, wherein: The strip-shaped winding units (1, 1', 1", 1"', 1"") are arranged in a spiral shape in the stator core (11).

10. A method for winding a stator (10) for an electric machine, the method comprising the following method steps: a. Producing a first winding unit (12) and a second winding unit (13), each having at least a first winding conductor and a second winding conductor (2, 2'), such that the first winding conductor and the second winding conductor extend in a first layer and a second layer (L1, L2) of the respective winding unit (12, 13) and each comprise: i. a plurality of slot sections (3), the plurality of slot sections extending straightly along the transverse direction (Q) of the winding units (12, 13) and arranged parallel to each other, ii. a plurality of first curved end sections (5), each of which connects two slot sections (3) of the associated winding conductor (2, 2') and is arranged on a first longitudinal side of the winding unit (12, 13), iii. a plurality of second curved end sections (6), each of which connects two slot sections (3) of the associated winding conductor (2, 2') to one another and is arranged on a second longitudinal side of the winding unit (12, 13) opposite to the first longitudinal side, b. arranging the slot segments (3) of the first winding unit (12) in a plurality of slots of the stator core (11) spaced apart in the circumferential direction, c. arranging the slot segments (3) of the second winding unit (13) in a plurality of slots spaced apart in the circumferential direction of the stator core (11), so that the second winding unit (13) is placed offset in the circumferential direction relative to the first winding unit (12), and the slot segments (3) of the first winding unit and the second winding unit (12, 13) are arranged in the same slot; d. Arrange the first slot section (3) in the first slot at a first radial position, and arrange the second slot section (3) directly connected to the first slot section (3) via a first curved end section (5) in the second slot at a second radial position, the second radial position being offset from the first radial position by two radial positions; arrange the third slot section (3) in the first slot at a third radial position, the third radial position being offset from the first radial position by one radial position, and arrange the fourth slot section (3) directly connected to the third slot section (3) via a second curved end section (6) in the second slot at a fourth radial position, the fourth radial position being the same as the third radial position.

11. The winding method according to claim 10, wherein: The first winding unit and the second winding unit (12, 13) are offset from each other in the circumferential direction when applied to a cylindrical drive core shaft (14), the drive core shaft (14) is axially displaced into an inner space enclosed by the stator core (11), and the winding units (12, 13) are radially expanded outward from the drive core shaft (14) into the slots of the stator core (11).

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