Winding mat for an electric machine

Description

[0001] The invention relates to a stator of a dynamo-electric machine comprising a stator body with stator slots and at least one winding mat arranged in the stator slots. The invention further relates to a method for manufacturing a winding mat for such a stator.

[0002] It is known to design such winding mats as so-called wave windings. Such a wave winding comprises several wave winding conductors, in each of which slot sections running in the slots of the stator are connected to head sections arranged in the area of ​​the winding heads. In a radial flux machine with slots running axially in the stator, these slot sections of each wave winding conductor are located alternately on both end faces of the stator carrier when viewed circumferentially. In this context, a stator carrier is understood to be the non-electromagnetically active part of the stator, i.e., for example, a stator body without the field-generating coils. A stator body can, in particular, be designed as a stator lamination stack, which is formed from stacked and electrically insulated stator laminations.

[0003] US Patent 6,894,414 B1 discloses a dynamoelectric machine in which the stator is manufactured as a so-called rolled toothed chain. A winding mat, forming a distributed winding, is first inserted into the stator slots of such a flat toothed chain. The extent of the winding mat in the winding direction corresponds to the extent of the flat toothed chain and thus to the circumference of the resulting cylindrical stator. After the winding mat is inserted, the toothed chain is bent into a cylindrical shape. The ends of the toothed chain are then welded together.

[0004] From EP 259 77 54 A1 a dynamoelectric machine with a wave winding is known in which the distance between two slot sections connected via a head section varies at least partially.

[0005] From US 2020 / 0052537 A1, a method is known in which a first and a second wave winding conductor are provided, a first section of the first wave winding conductor is bent at a selected point, the second wave winding conductor is placed on a second section of the first wave winding conductor, and the first section of the first wave winding conductor is bent back such that a first subsection of the second wave winding conductor lies under the first subsection of the first wave winding conductor and a second subsection of the second wave winding conductor lies on the second subsection of the first wave winding conductor, thereby forming a first conductor pair. Wave winding conductors undergo a change of position in the stator slots along their winding direction. This change of position is offset from the center of the wave winding's extent.The document does not reveal that each wave winding conductor undergoes a layer change by exactly one radial position in the stator slots at the midpoint of its extension in the winding direction.

[0006] The invention is based on the objective of providing a stator for a dynamoelectric machine with a continuous winding scheme that is easy to manufacture. This objective is achieved by a stator for a dynamoelectric machine with the features according to claim 1. Furthermore, the objective is achieved by a method for manufacturing a winding mat for a stator of a dynamoelectric machine according to claim 13.

[0007] Advantageous embodiments of the invention can be found in the dependent patent claims.

[0008] The stator can initially comprise, in particular, axially aligned stator slots.

[0009] The stator slots can also have a chamfer to reduce torque ripple and slot cogging torque. At least one winding mat is arranged in the stator slots. This winding mat is designed as a distributed winding. It contains two sets of continuous wave winding conductors for each phase of the machine. Each wave winding conductor comprises slot sections that can be arranged in different radial positions within the stator slots. In addition, each wave winding conductor includes end sections that connect two slot sections outside the stator slots in the area of ​​the winding heads. In a so-called wave winding, these end sections are arranged alternately at the two end faces of the stator for each wave winding conductor.

[0010] In an electric machine with wave windings, parallel winding branches per phase are often necessary because, especially with wave windings, a smaller conductor height is used (particularly compared to so-called hairpin windings), thus increasing the number of conductors in the slot. To limit the induced phase voltage, several winding branches are connected in parallel.

[0011] The so-called number of holes q defines the number of slots per pole and phase of the dynamo-electric machine. Each phase can have q continuous wave winding conductors, the slot sections of which are distributed across a slot block of q adjacent stator slots per pole. Thus, the wave winding conductors of a phase can occupy different slots within a slot block and also assume different positions in the radial direction within a slot, since, according to the invention, several conductors are arranged one above the other in the stator slots.

[0012] To prevent the formation of circulating currents in a parallel connection of wave-wound conductors of a specific strand, the sequence of the slot sections of the different wave-wound conductors of a set can be interchanged between the slot blocks such that each winding conductor occupies each of the q possible circumferential positions in a slot block an equal number of times. Furthermore, it is provided that each wave-wound conductor undergoes a position change by exactly one radial position in the stator slots at the midpoint of its extent in the winding direction.

[0013] The result of these two measures is that each wave winding conductor occupies every possible radial position in combination with every possible position within the slot block at least once and with equal frequency. The possible combinations of circumferential position within a slot block and radial position are thus evenly distributed among the wave winding conductors. In this way, circulating currents are effectively avoided when the winding conductors are connected in parallel. This also applies if the stator is designed with several winding mats of this configuration, for example, to increase the number of parallel connections. Every equivalent radial position-slot combination is occupied in each winding mat in this embodiment.By continuously swapping the conductor order of a strand in the winding head and by changing the radial position in the middle of the extension, and thus in particular according to p poles of the wave winding conductor in the winding direction, this rule is fulfilled for every conductor of every strand. Here, p denotes the number of pole pairs of the stator.

[0014] The stator body can have a toothed chain bent into a cylindrical shape with at least one axially extending joint where the ends of the bent toothed chain are connected. This design has the advantage that the stator slots can be very easily fitted with a winding mat when the toothed chain is unwound. In comparison, inserting a winding mat into a cylindrically shaped stator body can be a complex process.

[0015] Especially when the stator body is designed as a toothed chain, it is particularly advantageous if the extent of the winding mat in the winding direction corresponds to the inner circumference of the stator.

[0016] The number of pole pairs p of the stator can be an integer multiple of q. If the number of pole pairs p is a multiple of the number of holes q, each possible position within a slot block is occupied multiple times by a wave winding conductor of one set in each of the two possible radial positions within the stator slots.

[0017] The wave winding conductors of a set can, in a linearly propagated state, exhibit axial symmetry with respect to a crossing scheme of the end faces, with an axis of symmetry aligned parallel to a slot section. This ensures that each slot position within a slot block is occupied at least once in each of the two radial positions by a wave winding conductor of a set, and that the occupancy of these positions or radial positions is uniformly distributed among the different wave winding conductors of a set.

[0018] The stator comprises a first partial winding mat, which includes exactly one first set of wave winding conductors for each strand. These first sets are interlocked in an X-shape at the layer transitions, such that at the intersection points of the wave winding conductors of the first and second strands, on one side of the layer transition, the wave winding conductors of the first strand always lie above those of the second strand, and on the other side, the wave winding conductors of the second strand always lie above those of the first strand. This allows the sets of wave winding conductors for the different strands to be pre-configured very easily and then assembled into the first partial winding mat.

[0019] A similar approach can be taken with a second partial winding mat. This means that the stator has a second partial winding mat, which comprises exactly one second set of wave winding conductors for each strand, with said second sets being interlocked in an X-shape in the area of ​​the layer change, so that at the intersection points of the wave winding conductors of a first and second strand, on one side of the layer change, the wave winding conductors of the first strand always lie above those of the second strand, and on the other side, the wave winding conductors of the second strand always lie above those of the first strand.

[0020] A complete winding mat can now be formed from the first and second partial winding mats. The second partial winding mat can be rotated 180 degrees around an axis aligned with the winding direction relative to the first partial winding mat while in a linearly unwound state. The partial winding mats can be interlocked in an X-shape at the layer change, so that the wave winding conductors of the first partial winding mat are always above the wave winding conductors of the second partial winding mat on one side of the layer change, and always below the wave winding conductors of the second partial winding mat on the other side of the layer change.

[0021] This results in particularly compact winding heads if at least areas of the head sections of each wave winding conductor run offset on one side beyond the layer change in the direction of the slot opening compared to the respective connected slot sections, and on the other side beyond the layer change in the direction of the slot bottom in the direction of the respective connected slot sections.

[0022] The maximum offset of the head sections can each correspond to half a radial position and thus to half the conductor extension in the radial direction.

[0023] When the first and second partial winding mats are nested together, the offset of the head sections results in a particularly compact design. The offset of the first partial winding mat is always opposite to the offset of the second partial winding mat. These relationships reverse at the layer change when viewed in the winding direction.

[0024] A dynamo-electric machine with a stator according to one of the embodiments described above is particularly suitable as a traction drive for an electric or hybrid vehicle. It is easy to manufacture and therefore suitable for large production runs. Its electromagnetic behavior is highly advantageous due to the elimination of circulating currents.

[0025] Furthermore, the invention relates to a method for manufacturing a winding mat for a stator of a dynamoelectric machine. In this method, a first partial winding mat is initially produced. For this purpose, a first set of q wave winding conductors is provided for each strand of the stator in a first step. These wave winding conductors each comprise slot sections that are to be arranged in stator slots of a stator body of the dynamoelectric machine, and head sections that each connect two slot sections of a wave winding conductor in the region of the winding heads of the machine. Each wave winding conductor undergoes a position change by exactly one radial position in the stator slots at the midpoint of its extension in the winding direction.

[0026] The q wave winding conductors are arranged such that q adjacent slot sections of the respective wave winding conductors follow one another at intervals of two stator slots. It is advantageous if the sequence of the slot sections of the different wave winding conductors within a set is interchanged, so that each wave winding conductor occupies each of the q possible positions within a slot block equally often. For example, if a slot block comprises four possible positions, and the stator thus has four holes, the slot sections of the wave winding conductors involved in the set can be equally distributed across positions 1, 2, 3, and 4.

[0027] Subsequently, all the first sets of wave winding conductors formed in this way are assembled or joined together to form the first partial winding mat.

[0028] A second partial winding mat can be produced in the same way as the first partial winding mat.

[0029] The two resulting partial winding mats can then be joined together. During this joining process, the groove sections of the involved wave winding conductors undergo a change of position. This occurs such that, before the change of position, the wave winding conductors of the first partial winding mat are positioned below, and after the change of position, they are positioned above, the wave winding conductors of the second partial winding mat. Therefore, after the partial winding mats are joined together, groove sections of the wave winding conductors of the first partial winding mat lie above groove sections of the wave winding conductors of the second partial winding mat on one side of the change of position, while the situation on the other side of the change of position is exactly reversed.In a subsequent arrangement of the resulting winding mat in a stator body of the dynamo-electric machine, two radial positions are already occupied by the winding mat, whereby each wave winding conductor can occupy each of the two radial positions equally often in each of the q possible positions within a slot block.

[0030] The invention will now be explained in more detail with reference to the exemplary embodiments shown in the figures. The figures show: Figure 1: a schematic representation of a first set of wave-wound conductors, Figure 2: a constructive realization of the first set of wave-wound conductors, Figure 3: a joining of three first sets of wave-wound conductors, Figure 4: a first partial winding mat as a result of the three joined first sets of wave-wound conductors, Figure 5: a joining of two partial winding mats to form a winding mat, Figure 6: a stack of several winding mats, Figure 7: a stator body with a winding stack inserted in stator slots of the stator body, Figure 8: a first wiring diagram for a winding according to an embodiment of the invention, Figure 9: a second wiring diagram for a winding according to an embodiment of the invention, Figure 10: a first embodiment of a toothed chain for forming a cylindrical stator body, Figure 11: a second embodiment of a toothed chain for forming a cylindrical stator body.Figure 12: a third embodiment of a toothed chain for forming a cylindrical stator body, Figure 13: a fourth embodiment of a toothed chain for forming a cylindrical stator body, Figure 14: a fifth embodiment of a toothed chain for forming a cylindrical stator body, and Figure 15: a sixth embodiment of a toothed chain for forming a cylindrical stator body.

[0031] Figure 1 Figure 1 shows a schematic representation of a first set 4 of wave-wound conductors according to an embodiment of the invention. The wave-wound conductors 6 each comprise slot sections 7, which are connected to one another via head sections 8. After the wave-wound conductors 6 have been inserted into stator slots of a stator body of a dynamo-electric machine, the head sections 8 form the winding heads projecting axially beyond the stator body, while the slot sections 7 are inserted into stator slots of the stator body.

[0032] The first set 4 shown is assigned to exactly one strand of the machine and comprises four wave winding conductors 6. These four wave winding conductors 6 are arranged side by side in a slot block of four slots in the stator body. The so-called number of holes q of the stator, the number of slots per pole and strand, is therefore q=4. The number of pole pairs of the stator, which includes the set shown in its stator winding, is p=4.

[0033] The machine is a three-phase machine. Since a set of wave winding conductors occupies four slots per slot block, and each of the eight poles of the stator is assigned exactly one slot block, there are 32 stator slots for each phase of the machine. Thus, the total number of slots for the stator with its three phases is N = 96.

[0034] Since each slot block comprises four slots, a slot section 7 of a wave-wound conductor 6 can occupy four different positions in each slot block. As the schematic representation of the first set 4 of wave-wound conductors 7 shows, each wave-wound conductor 7 always changes its position from slot block to slot block.

[0035] Assume a continuous numbering of the positions within the slot blocks from left to right, ascending continuously from position one to position four. The wave winding conductor 6 in position one in the first slot block from the left is located in position four in the following second slot block. In the third slot block from the left, this wave winding conductor 6 is located in position three. In the fourth slot block, it is in position two. In the fifth slot block, this wave winding conductor 6 moves to position three and moves back to position two in the sixth slot block. In the seventh slot block, the wave winding conductor 6 is again in position one. In the eighth slot block, it occupies position four.

[0036] The arrangement formed by the first set of 4 wave-wound conductors 6 exhibits axial symmetry with respect to an axis of symmetry 9, which divides the first set of 4 into two equal halves in the middle when viewed in the winding direction. This axial symmetry is manifested in the design of the winding heads. At the pole located directly above the axis of symmetry 9, the head sections 8 do not cross. The crossing arrangement of the other head sections 8 is axially symmetric with respect to the axis of symmetry 9.

[0037] The slot positions are occupied analogously by the other wave-winding conductors 6 involved in the first set 4. The wave-winding conductors 6 therefore do not follow a constant pitch. Rather, the distance between two slot sections 7 of a wave-winding conductor changes continuously.

[0038] In the head sections 8 arranged in the winding head, a positive and a negative corresponding head section conductor position are defined. These are each offset by half a conductor height in the positive and negative z-direction, respectively. The dashed conductor line in Figure 1 The solid line is intended to illustrate an offset into the corresponding positive position, and the solid line an offset into the corresponding negative position of the head section of the ladder.

[0039] The head sections 8 to the left of the axis of symmetry 9 are initially oriented towards the negative z-axis when viewed from the left. Upon reaching a winding head tip 10, the orientation reverses, so that the slot sections 7 connected via a head section 8 are ultimately arranged in the same z-axis position. After the illustrated wave winding conductors 6 are installed in the stator body, this means that these slot sections 7 are arranged in the same radial position.

[0040] In the area to the right of the axis of symmetry 9, the course of the head sections 8 is exactly reversed. That is, viewed from left to right, a head section 8 initially runs in a positive z-direction up to the winding head tip 10 and then in a negative z-direction after the winding head tip, so that the groove sections 7 connected via said head section 8 are again in the same z-position and thus in the same radial position when installed.

[0041] At the axis of symmetry 9, and thus in the middle of the first set 4 of wave winding conductors 6 of a strand of the machine, a change of position in the z-direction takes place. On both sides of the winding head tip 10 located here, the head sections 8 run in the negative z-direction. Here, too, the offset on both the left and right sides of the winding head tip 10 is equal to half a conductor width in the radial direction. However, due to the identical orientation of this offset in the z-direction, this results in a positional offset of the slot sections 7 connected via the head section 8 by exactly one conductor width. Therefore, the slot sections 7 on the right side of the axis of symmetry are positioned in the slots of the machine one radial position closer to the bottom of the slot than the slot sections 7 to the left of the axis of symmetry 9.

[0042] As a result, the distribution of the slot sections 7 shown within the first set 4, with respect to the possible positions within the slot blocks involved and with respect to the radial positions occupied by the wave winding conductors 8, ensures that each wave winding conductor 8 occupies every possible position in the slot block and every possible radial position equally often. Thus, even within a single set of wave winding conductors 8, the basis is established for preventing the formation of circulating currents despite parallel conductor loops if this scheme is consistently applied to all sets of wave winding conductors involved in the stator winding mat.

[0043] It is important to understand that the positive head section conductor position of the first partial mat conductor position corresponds to the negative winding head conductor position of the second partial mat conductor position, offset in the positive z-direction. Along the wave direction of a strand according to Fig. 1In the positive x-direction, after exiting the groove in the first partial mat conductor layer, there is an offset to the corresponding negative winding head conductor layer. In the second conductor layer, however, there is an offset to the corresponding positive winding head conductor layer after exiting the groove. This difference is caused by the layer change. Along the described positive wave direction, after exiting the groove, the conductors initially shift to the negative winding head conductor layer corresponding to the first partial mat conductor layer. At the winding head tip, the conductors shift to the winding head conductor layer positive to the first partial mat conductor layer. Therefore, upon entering the groove, there is an offset in the positive z-direction to the second partial mat conductor layer.A detailed design of the winding head reveals that even at the groove entries in the second partial mat conductor layer, which follow the positive wave direction, an offset in the positive z-direction is necessary. Therefore, at the groove exits, an offset in the positive direction must occur, as described above.

[0044] Figure 2 shows a constructive realization of the first sentence 4 of wave-wound conductors 6.

[0045] The conductors are bent over their short edge at the winding head tip 10. The q parallel conductors of a strand can be prefabricated separately. This makes it possible to first bend the conductors in the xy-plane and, in a second step, to imprint the necessary conductor offsets in the winding head using a punch. The sequence in which these conductors are to be inserted into each other varies for each winding scheme with different parameters and must be investigated separately in each case.

[0046] Based on Figure 2An example of such a plugging process will be discussed. Upon closer inspection, it can be seen that the second wave winding conductor 6 from the left in the left connection zone is arranged in front of the other conductors in the first and seventh winding head sections along the positive wave direction. In contrast, the conductor is arranged behind the other wave winding conductors 6 in the third and fifth winding head sections. In the remaining winding head sections, this conductor does not cross the other wave winding conductors 6, meaning that the wave winding conductor 6 is neither in front of nor behind any other wave winding conductor 6. This conductor must therefore be the last to be plugged into the already arranged conductors of the strand in the positive y-direction. The described arrangement must be implemented in the winding head sections. The remaining wave winding conductors 6 are arranged one below the other in the same sequence in the respective winding head sections.Thus, the second conductor from the right in the left connection zone is always positioned in front of the first conductor from the right in the same zone. Inserting the remaining conductors is therefore unnecessary. They can then be nested together according to their sequence.

[0047] Figure 3 Figure 1 shows the joining of three first sets 4, 5, 13 of wave-wound conductors 6 to form a first partial winding mat, which therefore comprises one first set 4, 5, 13 wave-wound conductors 6 for each strand of the machine. The illustrated first sets 4, 5, 13 were manufactured in the same manner, in particular in connection with Figure 2 The described manner in which it was set.

[0048] The strands or the associated sets 4, 5, 13 of wave-wound conductors 6 must subsequently be joined together to form the first partial mat. The procedure described below is identical for each winding scheme with different parameters. Joining is achieved by means of an X-shaped insertion of the individual first sets 4, 5, 13 as shown in Figure 3 schematically illustrated. Since the arrangement of the head sections 8 between the respective strands to the left and right of the layer change is different, the individual strands must be pushed into each other in an x-shape in the y-direction and then twisted relative to each other, whereby this process can be carried out sequentially.

[0049] Following this principle, the first section of the second strand 5 is first inserted into the first section of the first strand 4. Then, the first section of the third strand 13 is inserted into the already formed partial mat, resulting in a completed first partial winding mat. Such a first partial winding mat 11, as a result of the three interlocked sections 4, 5, 13 of wave-wound conductors 6, is shown. Figure 4 The sequential assembly process is analogous for an alternative number of strands. The different arrangement of the head sections 8 to the left and right of the layer change is due to the different design of the winding head in the two sections.

[0050] Subsequently, a second partial winding mat 12 is produced using a completely analogous procedure. The first and second partial winding mats 11 and 12 are then joined together to form a winding mat 3. This process is described in Figure 5 clarifies.

[0051] As described above, each partial winding mat 11, 12 is divided into two areas in which the conductors lie in different radial positions. Therefore, when connecting the mats, the unoccupied layer-slot positions in the first partial winding mat 11 must be occupied by the second partial winding mat 12. Rotating the Figure 4 If the first partial winding mat 11 shown is rotated 180 degrees along the R-axis, it can be demonstrated in a constructive embodiment that the rotated first partial winding mat 11 (here referred to as the second partial winding mat 12) forms the counterpart to the original first partial winding mat 11 both in the area of ​​the groove sections 7 and in the area of ​​the head sections 8. Thus, the second partial winding mat 12 corresponds to the first partial winding mat 11 rotated 180 degrees along the R-axis.

[0052] Accordingly, only one version of the partial winding mat 11,12 is required in the process, which significantly reduces the manufacturing effort. Analogous to the joining of the sets 4,5,13 of the individual strands, these two opposing partial winding mats 11,12 must be shifted into each other in an x-shape in the y-direction and then twisted relative to each other. Viewed from the y-direction, the two partial winding mats 11,12 intersect along the layer change of the partial winding mats 11,12.

[0053] Figure 6 Figure 1 shows a winding stack 13 made up of several winding mats 3. In the illustrated embodiment, a flat winding with zn = 8 conductor layers is obtained.

[0054] Since each of the stacked winding mats 3 contains two conductor layers, four winding mats 3 are stacked for this purpose.

[0055] The winding mats 3 can be stacked directly on top of each other in the stator slots of a stator body. This is particularly easy if such a stator body, which is manufactured, for example, in the form of a stator lamination stack, is designed as a toothed chain.

[0056] The number of stacked winding mats 3 is flexibly selectable. Due to the construction of winding mats, which are made up of two partial mats 11, 12 and therefore form two conductor layers, the number of conductor layers of the entire winding stack 13 is even.

[0057] In Figure 6 It can also be seen that on both ends of the winding stack 13, connecting conductors 14 protrude from the winding stack 13. If the winding is inserted into a toothed chain, these conductors must become intertwined with the toothed chain as a result of the winding being coiled up.

[0058] Figure 7Figure 1 shows a stator body with a winding inserted into stator slots of stator body 2. The figure depicts a winding with stator body 2 in a coiled state and with braided connecting conductors 14. This schematic representation shows a winding without reversing the conductor order in the winding head, but with the parameters mentioned above.

[0059] Figure 8 shows a first circuit diagram for a winding stack 13 according to an embodiment of the invention and Figure 9 a second wiring diagram for a winding stack 13 according to an embodiment of the invention,

[0060] The stacked and rolled-up winding mats 3 must subsequently be interconnected. The interconnection is carried out analogously on both end faces. Furthermore, the interconnection is identical for all strands, which is why it will only be explained below using one strand as an example. In principle, it can be stated that the maximum number of parallel winding branches per end face corresponds to the number of holes q. Thus, for the complete winding stack 13, a maximum of a = 2q parallel winding branches per strand is possible. The interconnection must be examined individually for each desired number of holes. The necessary considerations are illustrated using an example of an interconnection with q = 4. After interlacing, the connecting conductors 14 are arranged in a matrix when viewed from the axial direction.The connecting conductors 14 of the different ends of a winding mat 3 are always arranged one above the other in the matrix-shaped arrangement, whereby when considering an end face only a partial mat 11,12 of the winding mat 3 is connected.

[0061] Figure 8 schematically shows the wiring for four and Figure 9for two parallel branches per end face. The different hatching is intended to illustrate the different conductors of the winding stack 13. Additionally, the corresponding transverse deviation in the winding head is shown in the matrix for each connection conductor level, which, as expected, alternates continuously. The reversal of the conductor arrangement during the layer change means that the conductor arrangement in both connection conductor levels of a winding mat 3 is also reversed in the area of ​​the connections. In the case of four parallel branches, the connection contacts are made in the uppermost and the lowermost connection conductor levels. Between these, the connections of different winding mats 3, which are one above the other, are connected in series. This connection concept can be applied to any other number of holes, whereby the number of parallel branches per end face must correspond to the number of holes.

[0062] In the Figures 10 to 15A total of six different embodiments of a stator body in the form of a so-called toothed chain 15 are shown. All these embodiments have in common that the stator body initially has two axially oriented end faces 18 on its circumference, which, after being fitted with a winding stack 13, are joined together, e.g., by welding, so that the stator body takes on a cylindrical shape.

[0063] In the first embodiment according to Figure 10 Within the toothed chain, the individual stator teeth 17 and stator grooves 16 are also provided with reference symbols.

[0064] In the first embodiment according to Figure 10The toothed chain 15 is in a completely linear, unwound form, so that the installation of the winding stack 13 is as easy as with a linear motor. Each individual stator tooth 17 has a certain angular clearance, which is essentially the same for all teeth. This clearance is dimensioned such that it is completely eliminated when the linear toothed chain 15 is bent into its closed cylindrical shape.

[0065] In the second embodiment Figure 11 Such circumferential flexibility is only present in the linearly extending area of ​​the stator lamination stack shown. This area adjoins a rigid section of the stator body that is already formed into a semicircular arc.

[0066] In the third embodiment Figure 12In contrast, two rigid stator body halves with a semicircular cross-section are articulated together at a point opposite the joining point with the two end faces 18.

[0067] In the fourth embodiment Figure 13 This joint point is realized by an area of ​​four articulated stator teeth 17 opposite the joining point.

[0068] In the fifth and sixth embodiments ( Figures 14 and 15 ) the area with the articulated stator teeth 17 is started from Figure 13 increased at the expense of the expansion of the rigid, arc-shaped stator areas. Reference symbol list

[0069] 1 Stator 2 Stator body 3 Winding mat 4, 5, 13 First sets 6 Wave winding conductors 7 Slot sections 8 Head sections 9 Axis of symmetry 10 Winding head tip 11 First partial winding mat 12 Second partial winding mat 13 Winding stack 14 Connection conductors 15 Toothed chain 16 Stator slots 17 Stator teeth 18 End face

Claims

1. A stator (1) of a dynamoelectric machine having a stator body (2) with stator slots (16) and at least one winding mat (3) designed as a wave winding with slot sections (7) arranged in the stator slots (16) in different radial positions one above the other and head sections (8) connecting the slot sections, wherein • each wave winding conductor (6) undergoes a layer change by exactly one radial position in the stator slots (16) at the midpoint of its extension in the winding direction and • the winding mat comprises a first partial winding mat (11) that comprises exactly one first set (4, 5, 13) of wave winding conductors (6) for each strand, wherein said first sets (4, 5, 13) are interlocked in an X-shape in the region of the layer change, such that, at the intersection points of the wave winding conductors (6) of a first and second strand, the wave winding conductors (6) of the first strand always lie above those of the second strand on one side of the layer change, and the wave winding conductors (6) of the second strand always lie above those of the first strand on the other side.

2. The stator (1) according to claim 1, wherein each set (4, 5, 13) has a number q of continuous wave winding conductors (6), the slot sections (7) of which are distributed over one slot block each of q adjacent stator slots (16) per pole.

3. The stator (1) according to claim 2, wherein the sequence of the slot sections (7) of the different wave winding conductors (6) of a set is interchanged between the slot blocks, such that each winding conductor (6) occupies each of the q possible circumferential positions in a slot block equally often.

4. The stator (1) according to either one of claims 2 or 3, wherein the number of pole pairs p of the stator is an integer multiple of q.

5. The stator (1) according to any one of the preceding claims having a second partial winding mat (12) comprising exactly one second set of wave winding conductors for each strand, wherein said second sets are interlocked in an X-shape in the region of the layer change, such that, at the intersection points of the wave winding conductors (6) of a first and second strand, the wave winding conductors (6) of the first strand always lie above those of the second strand on one side of the layer change, and the wave winding conductors (6) of the second strand always lie above those of the first strand on the other side.

6. The stator (1) according to claim 5, wherein the second partial winding mat (12) is rotated 180 degrees about an axis aligned in the winding direction relative to the first partial winding mat (11) in a linearly unwound state and wherein the partial winding mats (11, 12) are interlocked in an X-shape in the region of the layer change, such that the wave winding conductors (6) of the first partial winding mat (11) are always above the wave winding conductor (6) of the second partial winding mat (12) on one side of the layer change and are always below the wave winding conductor (6) of the second partial winding mat (12) on the other side of the layer change.

7. The stator (1) according to any one of the preceding claims, wherein the extension of the winding mat in the winding direction corresponds to the inner circumference of the stator.

8. The stator (1) according to any one of the preceding claims, wherein the wave winding conductors (6) of a set (4, 5, 13), when arranged in a linearly unfolded state, exhibit axial symmetry with respect to a crossing scheme of the head sections (8), the axis of symmetry (9) extending parallel to a slot section.

9. The stator (1) according to any one of the preceding claims, wherein at least regions of the end sections (8) of each wave winding conductor (6) are offset relative to the respective connected slot sections (7) on one side beyond the layer change in the direction of the slot opening and are offset relative to the respective connected slot sections (7) on the other side beyond the layer change in the direction of the slot base.

10. The stator (1) according to claim 9, wherein the maximum offset of the head sections (8) is equal in absolute magnitude to the amount of one-half of a radial position.

11. The stator (1) according to any one of the preceding claims, wherein the stator body (2) has a toothed chain (15) bent into a cylindrical shape having at least one axially extending joining point, at which the ends of the bent toothed chain are connected to one another.

12. A dynamoelectric machine having a stator (1) according to any one of the preceding claims.

13. A method for producing a winding mat (3) for a stator (1) of a dynamoelectric machine, in which a first partial winding mat (11) is produced by the following method steps: • providing a first set (4, 5, 13) of q wave winding conductors (6) for each strand of the stator (1), wherein the wave winding conductors (6) each comprise slot sections (7) and head sections (8) connecting the slot sections (7), wherein each wave winding conductor (6) undergoes a layer change by exactly one radial position in the stator slots (16) at the midpoint of its extension in the winding direction, • arranging the q wave winding conductors (6) such that the slot sections (7) of the respective wave winding conductors (6) follow one another at a distance of two stator slots (16) and • X-shaped interlocking of all first sets (4, 5, 13) to form the first partial winding mat (11), such that the wave winding conductors (6) undergo a layer change in the region of the midpoint of their extension, viewed in the winding direction, such that, at the intersection points of the wave winding conductors (6) of a first and second strand, the wave winding conductors (6) of the first strand always lie above those of the second strand on one side of the layer change, and the wave winding conductors (6) of the second strand always lie above those of the first strand on the other side.

14. The method according to claim 13 having the following further method steps: • producing a second partial winding mat (12) in the same way as the first partial winding mat (11), • interlocking the partial winding mats (11, 12), wherein the wave winding conductors (6) of the first partial winding mat (11) are arranged below the wave winding conductors of the second partial winding mat (12) before the layer change and above the wave winding conductors after the layer change.

15. The method according to claim 14, wherein the second partial winding mat (12) is rotated 180 degrees about an axis aligned in the winding direction relative to the first partial winding mat (11) and wherein the partial winding mats (11, 12) are interlocked in an X-shape in the region of the layer change.

16. The method according to any one of claims 13 to 15, wherein the sequence of the slot sections (7) of the different wave winding conductors (6) of the respective set is interchanged between the head sections (8), such that each winding conductor (6) occupies each of the q possible positions equally often.

17. The method according to claim 16, wherein the stator body (2) is produced as a linearly extended toothed chain which is bent into a cylindrical shape after being fitted with the winding mat (3).

18. The method according to any one of claims 13 to 17, wherein the extension of the winding mat (3) in the winding direction corresponds to the inner circumference of the stator (1).

19. The method according to any one of claims 13 to 18, wherein the wave winding conductors (6) of a set (4, 5, 13) are arranged relative to one another, such that they exhibit axial symmetry with respect to a crossing scheme of the head sections (8), the axis of symmetry (9) extending parallel to a slot section.

20. The method according to any one of claims 13 to 19, wherein at least one region of the end sections (8) of each wave winding conductor (6) is offset on one side beyond the layer change in the direction of the slot opening relative to the respective connected slot sections (7) and is offset on the other side beyond the layer change in the direction of the slot bottom relative to the respective connected slot sections (7), wherein, in particular, the offset corresponds in magnitude to one-half of the radial extent of the slot sections in the radial direction of the stator slots.