STATOR FOR AN ELECTRIC MACHINE, ELECTRIC MACHINE FOR DRIVING A VEHICLE AND VEHICLE

Description

[0001] The present invention relates to a stator for an electrical machine, wherein the stator has a stator winding with a number N of phase windings, a number P of pole pairs and a stator core in which slots are formed, wherein the stator winding is arranged in the slots; wherein the stator core is subdivided into 2·P·N winding zones that follow one another evenly in the circumferential direction; wherein the stator core has a plurality of recesses that extend in the axial direction from a first end face of the stator core to a second end face of the stator core opposite the first end face; wherein the recesses form at least a first arrangement and a second arrangement of recesses that follow one another in the circumferential direction; wherein in each arrangement, at least two recesses belong to one of the winding zones.wherein, in each arrangement, each pair of circumferentially adjacent recesses belonging to the same winding zone has a first angular distance in the circumferential direction from each other; wherein, in each arrangement, each pair of circumferentially adjacent recesses belonging to different winding zones has a second angular distance in the circumferential direction from each other.;

[0002] The invention also relates to an electric machine for driving a vehicle.

[0003] Document US 2015 / 0381000 A1 discloses a stator for a rotating electric machine, comprising an annular stator core having a plurality of pairs of first-phase slots, a plurality of pairs of second-phase slots, and a plurality of third-phase slots sequentially and repeatedly provided in the circumferential direction; and a stator winding comprising a first-phase winding, a second-phase winding, and a third-phase winding arranged on the stator core to be received in the corresponding slots. Portions of the stator winding received in the slots are radially stacked in four layers.

[0004] The articles by I. Petrov, P. Ponomarev, and J. Pyrhonen: "Torque ripple reduction in 12-slot 10-pole fractional slot permanent magnet synchronous motors with non-overlapping windings by implementation of unequal stator teeth widths," International Conference on Electrical Machines (ICEM), pp. 1455-1460, 2014; by I. Petrov, P. Ponomarev, Y. Alexandrova, and J. Pyrhonen: "Unequal Teeth Widths for Torque Ripple Reduction in Permanent Magnet Synchronous Machines With Fractional-Slot Non-Overlapping Windings," IEEE Trans. Magn, vol. 51, no. 2, pp. 1-9, 2015; and by P. Ponomarev, I. Petrov, and J. Pyrhonen: "Torque ripple reduction in double-layer 18 / 16 TC-PMSMs by adjusting teeth widths to minimize local saturation," International Conference on Electrical Machines (ICEM), pp. 1461-1467, 2014 each disclose a stator with concentrated tooth coil windings and unequal stator tooth widths.

[0005] Document US 9 590 458 B2 discloses a stator core with stator slots.

[0006] During operation of an electrical machine with a stator featuring evenly spaced slots in the circumferential direction, parasitic forces arise. This can result in high torque ripple, which causes unwanted vibrations and operating noise.

[0007] The object of the invention is to provide a possibility for quieter operation of an electrical machine.

[0008] This object is achieved according to the invention in a stator core of the type mentioned at the outset in that each recess of the first arrangement forms a groove of the stator core in a continuous manner with a recess of the second arrangement, the recess of the first arrangement is arranged radially further inward than the recess of the second arrangement, and the recess of one of the first and second arrangements has a greater extent in the circumferential direction than the recess of the other of the first and second arrangements; wherein in at least one arrangement the first angular distance and the second angular distance are different, so that the arrangement is designed as a non-uniform arrangement.

[0009] The stator for an electrical machine has a stator winding. The stator winding has a number N of phase windings. The stator has a number P of pole pairs. The stator has a stator core. Slots are formed in the stator core. The stator winding is arranged in the slots. The stator core is divided into 2·P·N winding zones. The winding zones follow one another evenly in the circumferential direction. The stator core has a plurality of recesses. The recesses extend in the axial direction from a first end face of the stator core to a second end face of the stator core. The second end face is opposite the first end face. The recesses form at least a first arrangement and a second arrangement of recesses, each following one another in the circumferential direction. In each arrangement, at least two recesses belong to one of the winding zones.In each arrangement, each pair of circumferentially adjacent recesses belonging to the same winding zone has a first angular distance from each other in the circumferential direction. In each arrangement, each pair of circumferentially adjacent recesses belonging to different winding zones has a second angular distance from each other in the circumferential direction. Each recess of the first arrangement forms a slot of the stator core together with a recess of the second arrangement. The recess of the first arrangement is arranged radially further inward than the recess of the second arrangement. The recess of one of the first and second arrangements has a greater extent in the circumferential direction than the recess of the other of the first and second arrangements. In at least one arrangement, the first angular distance and the second angular distance are different, so that the arrangement is designed as a non-uniform arrangement.

[0010] The stator according to the invention is characterized in particular in that the recesses extending in the axial direction, at least in one arrangement, are not arranged uniformly in the circumferential direction, but are shifted with respect to a respective winding zone such that the second angular spacing of the pair of circumferentially adjacent recesses belonging to different winding zones is different. The stator according to the invention is further characterized in that the first and second arrangements of recesses, which are located at different radial positions, have different extensions in the circumferential direction.

[0011] The stator according to the invention can significantly reduce the occurrence of parasitic forces during operation of the electric machine, as cogging torques that trigger increased torque ripple are reduced. This advantageously enables quieter, particularly vibration- and noise-free, operation of the electric machine without any significant loss of performance.

[0012] The stator core is preferably designed as a laminated core. The recesses typically extend parallel to a longitudinal axis of the stator core in the axial direction. It is preferred that N = 3 or N is an integer multiple of 3. It is further preferred that P is equal to 2, 4, 6, or 8. Preferably, in the at least one arrangement, recesses for each m ≥ 2, in particular m = 2, 3, or 4, belong to one of the winding zones. The recesses of a respective arrangement preferably have the same shape when viewed from the first end face.

[0013] It is preferred that the recesses of a respective arrangement have the same shape when viewed from the first end face. In particular, the recesses of the first arrangement and the second arrangement each have two parallel, substantially radially extending long sides. The recesses of the first arrangement and / or the second arrangement are preferably rectangular. It is preferred that a shoulder is formed between the recesses of the first and second arrangements forming the same groove.

[0014] The first angular distance is preferably defined as the difference between the angular positions of the recesses of the pair of adjacent recesses belonging to the same winding zone. The second angular distance is preferably defined as the difference between the angular positions of the recesses of the pair of adjacent recesses belonging to different winding zones. The angular position of a respective recess can be defined as the angular position of a radial tangent to an edge of the recess, viewed from the first end face.

[0015] Preferably, in the non-uniform arrangement, the first angular distances of a respective pair of adjacent recesses are identical. Preferably, in the case of multiple non-uniform arrangements, the second angular distances are identical. The second angular distance can be smaller or larger than the first angular distance. In particular, the second angular distance is smaller or larger than the first angular distance by at least 360° / (2·P·N·m·20), preferably at least 360° / (2·P·N·m·10).

[0016] Preferably, the recesses of the second arrangement have a larger extent in the circumferential direction than the recesses of the first arrangement. This provides a larger cross-sectional area for a stator winding in the outer recesses, which can compensate for a radially varying distribution of losses during operation of the electric machine.

[0017] In a preferred embodiment of the stator according to the invention, the first arrangement and the second arrangement are formed as a non-uniform arrangement. It is also possible for the first and second angular distances of the first arrangement to correspond to those of the second arrangement.

[0018] Alternatively, the first arrangement may be configured as a non-uniform arrangement, and the recesses of the second arrangement may be arranged regularly in the circumferential direction of the entire stator core. According to a further alternative, the second arrangement may be configured as a non-uniform arrangement, and the recesses of the first arrangement may be arranged regularly in the circumferential direction of the entire stator core. This allows the slots to assume the offset shape provided for by the invention to enable quieter operation.

[0019] In an advantageous further development, it is provided that recesses forming a groove, which are adjacent to a recess belonging to another winding zone, are arranged such that they have a straight edge line extending in the radial direction. The edge line does not have to run exactly along the radial direction, especially if the recesses are rectangular and therefore do not extend exactly along the radial direction.

[0020] Alternatively, the recesses of the first arrangement and the second arrangement may be arranged regularly in the circumferential direction of the entire stator core. In this case, one of the arrangements described below may be designed as a non-uniform arrangement.

[0021] It can be provided that the recesses of one or more further arrangements form the slots connected to the first and second arrangements, wherein the recesses of the further arrangements are arranged radially further outwards than the recesses of the second arrangement and have a different, in particular greater, extent in the circumferential direction. Such slots can also be referred to as multi-stepped slots. Otherwise, all statements regarding the second arrangement can be transferred to the or a respective further arrangement. In particular, it can be provided that the or a respective further arrangement is designed as a non-uniform arrangement or that the recesses of the or a respective further arrangement are arranged regularly in the circumferential direction of the entire stator core.

[0022] The stator according to the invention preferably has a receiving space for a rotor of the electric machine. Furthermore, the stator core can have a lateral surface facing the receiving space. The lateral surface is preferably a radially inner lateral surface of the stator core, which, particularly in the electric machine, defines an air gap between the stator and rotor.

[0023] In an advantageous development, the recesses can form a third arrangement of recesses that follow one another in the circumferential direction and that extend through the lateral surface. Preferably, the number of recesses in the third arrangement corresponds to the number of recesses in the first arrangement. In particular, the number of recesses belonging to one of the winding zones in the first arrangement corresponds to the number of recesses belonging to one of the winding zones in the third arrangement.

[0024] The recesses of the third arrangement can form slot openings in the stator core, which connect the slots to the receiving space. This allows the formation of open slots in the stator. Alternatively, the recesses of the third arrangement can form pseudo-slot openings in the stator core, which form blind holes in the radial direction. The recesses of the second arrangement can be completely separated from the slots by the stator core. This allows the formation of closed slots with associated pseudo-slot openings, which enables a particularly favorable magnetic flux flow in the stator core.

[0025] Preferably, the recesses of the third arrangement are arranged at angular positions in the circumferential direction where they are overlapped by the grooves. When the recesses of the third arrangement form the groove openings, they can form a continuous radial connection from the receiving space into a respective groove. When the recesses of the third arrangement form the pseudo-groove openings, each recess of the third arrangement can lie on a radial line extending through one of the grooves.

[0026] The third arrangement can be designed as a non-uniform arrangement. This allows for quieter operation regardless of the offset design of the first and second arrangements. Alternatively, the recesses of the third arrangement can be arranged regularly in the circumferential direction of the entire stator core.

[0027] Furthermore, it can be provided that the recesses of a fourth arrangement penetrate the lateral surface. Preferably, the number of recesses in the fourth arrangement corresponds to the number of recesses in the first arrangement and / or the number of recesses in the third arrangement. In particular, the number of recesses belonging to one of the winding zones in the first arrangement and / or the number of recesses belonging to one of the winding zones in the third arrangement corresponds to the number of recesses belonging to one of the winding zones in the fourth arrangement.

[0028] Advantageously, the recesses of the fourth arrangement can be arranged at angular positions in the circumferential direction that lie between those of a respective pair of adjacent grooves. In particular, no radial line extending through a respective one of the recesses of the fourth arrangement extends through one of the grooves.

[0029] The recesses of the fourth arrangement can form pseudo-groove openings that form blind holes in the radial direction.

[0030] Preferably, the fourth arrangement is configured as a non-uniform arrangement. Alternatively, the recesses of the fourth arrangement can be arranged regularly in the circumferential direction of the entire stator core.

[0031] In the stator according to the invention, it can further be provided that the stator core is subdivided for a respective arrangement into first to 2·P·N-th sectors, wherein a respective sector is subdivided into first to m-th subsectors, wherein m corresponds to the number of recesses of the respective arrangement that belong to one of the winding zones, wherein for all 1 ≤ j ≤ 2·P·N and all 1 ≤ k ≤ m, the k-th recess belonging to the j-th sector is arranged completely in the k-th subsector of the j-th sector such that the outer boundary of the k-th subsector, viewed clockwise from the first end face, is a tangent to the edge of the k-th recess. In this case, first to (m-th) central angles of the first to (m-1)-th subsectors can correspond to the first angular distance, and an m-th central angle of the m-th subsector can correspond to the second angular distance.Typically, the sectors, sub-sectors and recesses are named in their order along the circumferential direction.

[0032] In a non-uniform arrangement, the mth central angle may be different from the first to (m-1)th central angles. If the recesses of an arrangement are regularly arranged in the circumferential direction of the entire stator core, the first to mth central angles may be identical.

[0033] The stator winding is preferably a distributed stator winding.

[0034] It is further preferred in the stator according to the invention if slots each form a receiving space for a predetermined number of shaped conductors from which the stator winding is formed. A so-called hairpin winding can be formed by the shaped conductors. The shaped conductors are preferably formed from bent, electrically conductive rods, in particular made of copper. Typically, a predetermined number between four and twelve shaped conductors are accommodated within a respective slot. This number of shaped conductors can fill a cross-sectional area of ​​the recess by at least 60%, preferably at least 80%, particularly preferably at least 90%. The shaped conductors typically have a rectangular cross-section, which may be rounded. Alternatively, the stator winding can also be formed from wound wires, in particular with a round cross-section.

[0035] Preferably, it can be provided that the stator winding extends further in the circumferential direction in the recesses of the second arrangement than in the recesses of the first arrangement. In particular, the shaped conductors accommodated in the recesses of the second arrangement extend further in a direction perpendicular to the radial direction than the shaped conductors accommodated in the recesses of the first arrangement.

[0036] The object underlying the invention is further achieved by an electric machine for driving a vehicle, comprising a stator according to the invention and a rotor rotatably mounted within the stator. The electric machine is preferably a synchronous machine or an asynchronous machine. The rotor can be a permanently excited rotor. In particular, the electric machine is configured to form part of a drivetrain of the vehicle. The vehicle can be a battery electric vehicle (BEV) or a hybrid vehicle.

[0037] Further advantages and details of the present invention will become apparent from the exemplary embodiments described below and from the drawings. These are schematic representations and show: Further advantages and details of the present invention will become apparent from the exemplary embodiments described below and from the drawings. These are schematic representations and show: Fig. 1 shows a schematic diagram of a conventional stator; Figs. 2 to 4 each show a cross section of a first exemplary embodiment of the stator according to the invention; Fig. 5 shows a cross section of a second exemplary embodiment of the stator according to the invention; Fig. 6 shows a cross section of a section of a third exemplary embodiment of the stator according to the invention; and Fig. 7 shows a schematic diagram of a vehicle with an exemplary embodiment of the electrical machine according to the invention.

[0038] Fig. 1 is a cross-section of a conventional stator 101.

[0039] The stator 101 comprises an N-phase (N = 3) distributed stator winding 102, which forms a pole pair (P = 1) of the stator, and a stator core 103, in which a plurality of recesses 104a-I are formed. The recesses 104a-I extend in the axial direction from a first end face, from the direction of which the cross section according to Fig. 1 viewed from the side facing away from the first end face, to a second end face of the stator core 103 opposite the first end face. The recesses 104a-l form a first arrangement 105a of recesses 104a-d and a second arrangement 105b of recesses 104e-h. A respective recess 104a-d of the first arrangement 105a, together with a recess 104e-h of the second arrangement 105b, forms a slot of the stator core 103. The recesses 104a-d of the first arrangement 105a are arranged radially further inward than the recesses 104e-h of the second arrangement 105b and have a smaller extension in the circumferential direction than the recesses 104e-h of the second arrangement 105b. The slots accommodate the stator winding 102. In addition, the recesses 104a-I form a third arrangement 105c of recesses 104i-I.The recesses 104i-I form slot openings which connect the recesses 104a-d of the first arrangement 105a with a receiving space 106 for a rotor by penetrating an inner surface 107 of the stator core 103.

[0040] The stator core is divided into six (2 P N) winding zones 108a-f, evenly spaced circumferentially. Of the recesses 104a-d, 104d-h, 104i-i of a respective arrangement 105a, 105b, 105c, m = 4 recesses each belong to one of the winding zones 108a-f.

[0041] In the first arrangement 105a, each pair of circumferentially adjacent recesses 104a-d belonging to the same winding zone 108a-f has a first angular distance 111a-c from each other in the circumferential direction. Furthermore, each pair of circumferentially adjacent recesses 104a, 104d belonging to different winding zones 108a-f has a second angular distance 111d from each other in the circumferential direction. The first and second angular distances are identical, so that the recesses 104a-d are arranged regularly in the circumferential direction of the entire stator core 103.

[0042] Thus, the stator core 103 for the first arrangement 105a can be divided into first to sixth (2·P·N-th) sectors 109a-f, which are Fig. 1 represented by solid radial arrows. A respective sector 109a-f is in turn subdivided into first to fourth (m-th) subsectors 110a-d, which are Fig. 1 for the first sector 109a are represented by dashed radial lines. For all 1 ≤ j ≤ 6 = 2 P N and all 1 ≤ k ≤ m = 4, the k-th recess 104a-d, which belongs to the j-th sector 109a-f, is arranged completely in the k-th subsector 110a-d of the j-th sector 109a-f such that the outer boundary of the k-th subsector 110a-d, viewed clockwise from the first end face, is a tangent to the edge of the k-th recess 104a-d. The central angles of a respective subsector 110a-d correspond to the first and second angular distances 111a-d and are identical, so that all recesses 104a-d are arranged at equidistant positions in the circumferential direction.

[0043] Analogously, the recesses 104e-h of the second arrangement 105b and the recesses 104i-I of the third arrangement 105c are also regularly arranged in the circumferential direction of the stator core 103.

[0044] Fig. 2 bis Fig. 4 are each a cross-section of a first embodiment of a stator 1.

[0045] The stator 1 comprises an N-phase (N = 3) distributed stator winding 2, which forms a pole pair (P = 1) of the stator 1, and a stator core 3, in which a plurality of recesses 4a-l, which extend in the axial direction from a first end face, from the direction of which on the cross section according to Fig. 2 as viewed from the front, extend to a second end face of the stator core 3 opposite the first end face. The recesses 4a-h form a first arrangement 5a of recesses 4a-d and a second arrangement 5b of recesses 4e-h. A respective recess 4a-d of the first arrangement 5a, together with a recess 4e-h of the second arrangement 5b, forms a slot A of the stator core 3. The recesses 4a-d of the first arrangement 5a are arranged radially further inward than the recesses 4e-h of the second arrangement 5b and have a smaller extension in the circumferential direction than the recesses 4e-h of the second arrangement 5b. The slots A accommodate the stator winding 102. In addition, the recesses 4a-l form a third arrangement 5c of recesses 4i-l. The recesses 4i-I form slot openings B, which connect the recesses 4a-d of the first arrangement 5a with a receiving space 6 for a rotor 52 (cf. Fig.11) by penetrating an inner surface 7 of the stator core 3.

[0046] The stator core is divided into six (2 P N) winding zones 8a-f, evenly spaced circumferentially. Of the recesses 4a-d, 4d-h, 4i-l of a respective arrangement 5a, 5b, 5c, m = 4 recesses each belong to one of the winding zones 8a-f.

[0047] In the first arrangement 5a, each pair of circumferentially adjacent recesses 4a-d belonging to the same winding zone 8a-f has a first angular distance 11a-c from each other in the circumferential direction. Furthermore, each pair of circumferentially adjacent recesses 4a, 4d belonging to different winding zones 8a-f has a second angular distance 11d from each other in the circumferential direction. The first angular distance 11a-c and the second angular distance 11d are different, so that the first arrangement 5a is designed as a non-uniform arrangement.

[0048] In the present embodiment, the second angular distance 11d is smaller than the first angular distance 11a-c. The first angular distances 11a-c of the pairs of circumferentially adjacent recesses 4a-d belonging to the same winding zone 8a-f are identical. A respective first angular distance 11a-c is greater than 360° / (2 P N m), whereas the second angular distance 11d is smaller than 360° / (2 P N m).

[0049] As in Fig. 3 Shown in detail, in the second arrangement 5b, each pair of circumferentially adjacent recesses 4e-h belonging to the same winding zone 8a-f has a first angular distance 15a-c from each other in the circumferential direction. Furthermore, each pair of circumferentially adjacent recesses 4e, 4h belonging to different winding zones 8a-f has a second angular distance 15d from each other in the circumferential direction. The first angular distance 15a-c and the second angular distance 15d are identical, so that the recesses 4e-h are regularly arranged in the circumferential direction of the entire stator core 3. Each angular distance 15a-d corresponds to 360° / (2 P N m).

[0050] The second angular distance 11d is visible (see Fig. 2 ) is selected such that the recesses 4d, 4h, which are adjacent to another winding zone 8a-f, form a straight edge line L of the slot A, extending essentially in the radial direction.

[0051] As in Fig. 4 Shown in detail, in the third arrangement 5c, each pair of circumferentially adjacent recesses 4i-l belonging to the same winding zone 8a-f has a first angular distance 19a-c from each other in the circumferential direction. Furthermore, each pair of circumferentially adjacent recesses 4e, 4h belonging to different winding zones 8a-f has a second angular distance 19d from each other in the circumferential direction. The first angular distance 19a-c and the second angular distance 19d are identical, so that the recesses 4i-l are arranged regularly in the circumferential direction of the entire stator core 3. Each angular distance 19a-d corresponds to 360° / (2 P N m).

[0052] Furthermore, in the first embodiment, the first and second angular distances 15a-d of the second arrangement 5b correspond to the first and second angular distances 19a-d of the third arrangement 5c, so that the groove openings B formed by the recesses 4i-l are located at identical relative positions to the recesses 4e-h forming the radially outer part of the grooves A.

[0053] Thus, the stator core 3 for the first arrangement 5a can be divided into first to sixth (2·P·N-th) sectors 9a-f, which are Fig. 2 represented by solid radial arrows. Each sector 9a-f is in turn subdivided into first to fourth (m-th) subsectors 10a-d, which are Fig. 2 for the first sector 9a are represented by dashed radial lines. For all 1 ≤ j ≤ 6 = 2 P N and all 1 ≤ k ≤ m = 4, the k-th recess 4a-d belonging to the j-th sector 9a-f is arranged completely in the k-th subsector 10a-d of the j-th sector 9a-f such that the outer boundary of the k-th subsector 10a-d, viewed clockwise from the first end face, is a tangent to the edge of the k-th recess 4a-d. The first to third [(m-1)-th] central angles of the first to third [(m-1)-th] subsectors 10a-c correspond to the first angular distances 11a-c and are identical. The first to third [(m-1)-th] central angles, on the one hand, and a fourth (m-th) central angle of a fourth (m-th) sub-sector 10d, corresponding to the second angular distance 11d, on the other hand, are different. In the present embodiment, the fourth central angle is smaller than each of the first to third central angles.

[0054] Furthermore, the stator core 3 for the second arrangement 5b can be divided into first to sixth (2·P·N-th) sectors 13a-f, which are Fig. 3 represented by solid radial arrows. A respective sector 13a-f is in turn subdivided into first to fourth (m-th) subsectors 14a-d, which are Fig. 3 for the first sector 13a are represented by dashed radial lines. For all 1 ≤ j ≤ 6 = 2 P N and all 1 ≤ k ≤ m = 4, the k-th recess 4e-h, which belongs to the j-th sector 13a-f, is arranged completely in the k-th subsector 14a-d of the j-th sector 13a-f such that the outer boundary of the k-th subsector 14a-d, viewed clockwise from the first end face, is a tangent to the edge of the k-th recess 4e-h. The first to third [(m-1)-th] central angles correspond to the first to third [(m-1)-th] subsectors 14a-c and are identical. The first to third central angles and a fourth (m-th) central angle corresponding to the second angular distance 15d are identical.

[0055] Furthermore, the stator core 3 for the third arrangement 5b can be divided into first to sixth (2·P·N-th) sectors 17a-f, which are Fig. 4 represented by solid radial arrows. A respective sector 17a-f is in turn subdivided into first to fourth (m-th) subsectors 18a-d, which are Fig. 4 for the first sector 17a are represented by dashed radial lines. For all 1 ≤ j ≤ 6 = 2 P N and all 1 ≤ k ≤ m = 4, the k-th recess 4i-l, which belongs to the j-th sector 17a-f, is arranged completely in the k-th subsector 18a-d of the j-th sector 17a-f such that the outer boundary of the k-th subsector 18a-d, viewed clockwise from the first end face, is a tangent to the edge of the k-th recess 4i-l. The first to third [(m-1)-th] central angles of the first to third [(m-1)-th] subsectors 14a-c correspond to the first angular distances 19a-c and are identical. The first to third central angles and a fourth (m-th) central angle corresponding to the second angular distance 19d are identical.

[0056] Furthermore, in the present embodiment, the central angles of the second arrangement 5b correspond to the central angles of the third arrangement 5c.

[0057] The stator 1 has a number of holes of four (m = 4), wherein the number of holes corresponds to the number of recesses 4a-d, 4e-h, 4i-I belonging to a respective winding zone 8a-f of a respective arrangement 5a, 5b, 5c.

[0058] The stator winding 2 is exemplary formed by a plurality of shaped conductors 16 (see Fig. 2 ), so that the stator winding 2 is a hairpin winding. For example, four shaped conductors 16, i.e., eight shaped conductors 16 per slot A, are arranged in each recess 4a-d, 4e-h of the first and second arrangements 5a.

[0059] Further exemplary embodiments of a stator 1 are described below, which correspond to the stator 1 according to the first exemplary embodiment except for the deviations described below. Identical or equivalent components are provided with identical reference numerals.

[0060] Fig. 5 is a cross section of a second embodiment of a stator 1.

[0061] According to the second embodiment, in the first arrangement 5a, the second angular distance 11d is greater than the first angular distance 11a-c. A respective first angular distance 11a-c is less than 360° / (2·P·N·m), whereas the second angular distance 11d is greater than 360° / (2·P·N·m). Furthermore, in the first arrangement 5a, the fourth (m-th) central angle of the fourth sub-sector 10d is greater than a respective one of the first to third [(m-1)-th] central angles of the first to third [(m-1)-th] sub-sectors 10a-c.

[0062] Fig. 6 is a cross-section of a section of a third embodiment of a stator 1 with a third embodiment of a stator core 3.

[0063] According to the third embodiment, a fourth arrangement 5d of recesses 4m-p is provided. The recesses 4m-p of the fourth arrangement 5c are designed as pseudo-groove openings that penetrate the lateral surface 7 and are arranged at positions in the circumferential direction that lie between those of a respective pair of adjacent recesses 4a-d of the first arrangement 5a.

[0064] In the fourth arrangement 5d, each pair of circumferentially adjacent recesses 4m-p belonging to the same winding zone 8a-f has a first angular distance 24a-c from each other in the circumferential direction. Furthermore, each pair of circumferentially adjacent recesses 4m, 4p belonging to different winding zones 8a-f has a second angular distance 24d from each other in the circumferential direction. The first angular distance 24a-c and the second angular distance 24d are different, so that the fourth arrangement 5d is designed as a non-uniform arrangement.

[0065] In the present embodiment, the second angular distance 24d is smaller than the first angular distance 24a-c. The first angular distances 24a-c of the pairs of circumferentially adjacent recesses 4m-p belonging to the same winding zone 8a-f are identical. A respective first angular distance 24a-c is greater than 360° / (2 P N m), whereas the second angular distance 24d is smaller than 360° / (2 P N m).

[0066] Thus, the stator core 3 for the fourth arrangement 5d can be divided into first to sixth (2·P·N-th) sectors 22a-f, of which Fig. 6 only the sectors 22a, 22b, 22f are shown. Each sector 22a-f is in turn subdivided into first to fourth (m-th) subsectors 23a-d, which are Fig. 2 for the first sector 22a are represented by dashed radial lines. For all 1 ≤ j ≤ 6 = 2 P N and all 1 ≤ k ≤ m = 4, the k-th recess 4m-p, which belongs to the j-th sector 22a-f, is arranged completely in the k-th subsector 23a-d of the j-th sector 22a-f such that the outer boundary of the k-th subsector 23a-d, viewed clockwise from the first end face, is a tangent to the edge of the k-th recess 4m-p. The first to third [(m-1)-th] central angles of the first to third [(m-1)-th] subsectors 23a-c correspond to the first angular distances 24a-c and are identical. The first to third [(m-1)-th] central angles, on the one hand, and a fourth (m-th) central angle, corresponding to the second angular distance 24d, of a fourth (m-th) sub-sector 23d, on the other hand, are different. In the present embodiment, the fourth central angle is smaller than a respective one of the first to third central angles.

[0067] According to a further embodiment, which corresponds to one of the previously described embodiments, the slots are designed as closed slots separated from the receiving space 6 by the stator core 3. Furthermore, the recesses 4i-I of the third arrangement 5c form pseudo-slot openings designed as blind holes.

[0068] According to further embodiments, the second arrangement 5b is / are designed as a non-uniform arrangement and / or the third arrangement 5c is / are designed as a non-uniform arrangement.

[0069] Fig. 7 is a schematic diagram of a vehicle 50 with an embodiment of an electric machine 51.

[0070] The electric machine 51 has a stator 1 according to one of the previously described embodiments and a rotor 52 rotatably mounted within the stator 1. The electric machine 51 is designed as a synchronous machine, in particular a permanent magnet machine, or as an asynchronous machine and is configured to drive the vehicle 50. The electric machine 51 is therefore part of a drive train 53 of the vehicle 50. The vehicle 50 is a battery electric vehicle (BEV) or a hybrid vehicle.

Claims

1. Stator (1) for an electric machine (51), wherein - the stator (1) has a stator winding (2) with a number N of phase windings, has a number P of pole pairs, and has a stator core (3) in which slots (A) are formed, wherein the stator winding (2) is arranged in the slots (A); wherein - the stator core (3) is subdivided into 2·P·N winding zones (8a-f) which follow one another in a circumferential direction in a uniform manner; wherein - the stator core (3) has a multiplicity of cutouts (4a-l) which extend in an axial direction from a first end face of the stator core (3) to a second end face of the stator core (3), which is situated opposite the first end face; - the cutouts (4a-p) form at least a first arrangement (5a) and a second arrangement (5b) of cutouts (4a-d, 4e-f) which in each case follow one another in the circumferential direction; wherein, - in each arrangement (5a-d), at least two cutouts (4a-d, 4e-h, 4i-l, 4m-p) belong to one of the winding zones (8a-f); wherein, - in each arrangement (5a-d), each pair of cutouts (4a-d, 4e-h, 4i-l, 4m-p) situated adjacently in the circumferential direction and belonging to the same winding zone (8a-f) have a first angular spacing (11a-c, 15a-c, 19a-c, 24a-c) to one another in the circumferential direction; wherein, - in each arrangement (5a-d), each pair of cutouts (4a, 4d, 4e, 4h, 4i, 41, 4m, 4p) situated adjacently in the circumferential direction and belonging to different winding zones (8a-f) have a second angular spacing (11d, 15d, 19d, 24d) to one another in the circumferential direction; wherein - each cutout (4a-d) of the first arrangement (5a) contiguously forms together with a cutout (4e-h) of the second arrangement (5b) a slot (A) in the stator core (3), the cutout (4a-d) of the first arrangement (5a) is arranged radially further to the inside than the cutout (4e-h) of the second arrangement (5b), and the cutout (4e-h) of one of the first and second arrangements (5b) has a greater extent in the circumferential direction than the cutout (4a-d) of the other one of the first and second arrangements (5a); wherein, - in at least one arrangement (5a-d), the first angular spacing (11a-c, 15a-c, 19a-c, 24a-c) and the second angular spacing (11d, 15d, 19d, 24d) are different, so that the arrangement (5a-d) is formed as a non-uniform arrangement.

2. Stator core according to Claim 1, wherein the cutouts (4e-h) of the second arrangement (5b) have a greater extent in the circumferential direction than the cutouts (4a-d) of the first arrangement (5a).

3. Stator core according to Claim 1 or 2, wherein - the first arrangement (5a) and the second arrangement (5b) are formed as a non-uniform arrangement, or - the first arrangement (5a) is formed as a non-uniform arrangement and the cutouts (4e-h) of the second arrangement (5b) are arranged in a regular manner in the circumferential direction of the complete stator core (3), or - the second arrangement (5b) is formed as a non-uniform arrangement and the cutouts (4a-d) of the first arrangement (5a) are arranged in a regular manner in the circumferential direction of the complete stator core (3), or - the cutouts (4a-d, 4e-h) of the first arrangement (5a) and of the second arrangement (5b) are arranged in a regular manner in the circumferential direction of the complete stator core (3).

4. Stator core according to one of the preceding claims, wherein the stator core (3) has a receiving space (6) for a rotor (52) of the electric machine (51) and has a lateral surface (7) which faces towards the receiving space (6).

5. Stator core according to Claim 4, wherein the cutouts (4a-p) form a third arrangement (5c) of cutouts (4i-l) which in each case follow one another in the circumferential direction and which extend through the lateral surface (7).

6. Stator according to Claim 5, wherein the cutouts (4i-l) of the third arrangement (5c) form slot openings (B) in the stator core (3), which connect the slots (A) to the receiving space (6), or pseudo slot openings in the stator core (3), which form blind holes in the radial direction.

7. Stator according to Claim 5 or 6, wherein the cutouts (4i-l) of the third arrangement (5c) are arranged at angular positions in the circumferential direction at which the slots (A) overlap them.

8. Stator according to one of Claims 5 to 7, wherein the third arrangement (5c) is formed as a non-uniform arrangement.

9. Stator according to one of Claims 5 to 7, wherein the cutouts of the third arrangement (5b) are arranged in a regular manner in the circumferential direction of the complete stator core (3).

10. Stator according to one of Claims 4 to 9, wherein the cutouts (4a-p) form a fourth arrangement (5d) of cutouts (4m-p) which in each case follow one another in the circumferential direction and which extend through the lateral surface (7).

11. Stator according to Claim 10, wherein the cutouts (4m-p) of the fourth arrangement (5d) are arranged at angular positions in the circumferential direction that are between those angular positions of a respective pair of adjacent slots (A).

12. Stator according to Claim 10 or 11, wherein the cutouts of the fourth arrangement (5d) form pseudo slot openings (C), which form blind holes in the radial direction.

13. Stator according to one of Claims 10 to 12, wherein the fourth arrangement (5d) is formed as a non-uniform arrangement.

14. Stator according to one of Claims 10 to 12, wherein the cutouts (4m-p) of the fourth arrangement (5d) are arranged in a regular manner in the circumferential direction of the complete stator core (3).

15. Electric machine (51) for driving a vehicle (50), comprising a stator (1) according to one of the preceding claims and a rotor (52) which is mounted rotatably within the stator (1).