CN117639307A - Stator, motor and vehicle - Google Patents

Abstract

The invention discloses a stator, a motor and a vehicle, wherein the stator comprises: a stator core; the stator winding comprises a first coil and a second coil, wherein the first coil comprises a first in-slot conductor, a first circumferential conductor and a first connecting conductor which extends along the radial direction of the stator core, the first in-slot conductor of the first coil comprises at least two layers of first conductor groups which are arranged along the radial direction of the stator core, and the first connecting conductor comprises at least one layer of second conductor groups which are arranged along the axial direction of the stator core; the second coil comprises a second groove inner conductor, a second circumferential conductor and a second connecting conductor extending along the axial direction of the stator core, the second groove inner conductor comprises at least two layers of third conductor groups distributed along the circumferential direction of the stator core, the second circumferential conductor comprises at least one layer of fourth conductor groups distributed along the axial direction of the stator core, the number of layers of the second conductor groups is smaller than that of the first conductor groups, and the number of layers of the fourth conductor groups is smaller than or equal to that of the third conductor groups. The stator according to the embodiment of the invention has small axial occupied space.

Description

Stator, motor and vehicle

Technical Field

The invention relates to the technical field of vehicles, in particular to a stator, a motor and a vehicle.

Background

In the related art, most of flat wire winding motors adopt hairpin windings, the working procedures of which comprise hairpin winding forming, twisting and flaring, welding and the like, the technological requirements of each working procedure are very complex, and the structure limits the winding mode of flat wires, thereby being not beneficial to improving the performance of the motor. And the axial height of the winding of the motor is higher, so that the axial size of the motor is large, and the occupied space of the motor is large.

Disclosure of Invention

The present invention aims to solve at least one of the technical problems existing in the prior art. It is therefore an object of the present invention to provide a stator whose stator windings have a small axial dimension, which is advantageous for reducing the axial space taken up by the stator.

The invention also provides a motor with the stator.

The invention further provides a vehicle with the motor.

A stator according to an embodiment of the present invention includes: a stator core having a plurality of stator slots; a stator winding including a first coil and a second coil; the first coil comprises a first in-slot conductor positioned in the stator tooth slot, a first circumferential conductor extending along the circumferential direction of the stator core and a first connecting conductor extending along the radial direction of the stator core, the first connecting conductor connects the first in-slot conductor and the first circumferential conductor, the first in-slot conductor comprises at least two layers of first conductor groups arranged along the radial direction of the stator core, each layer of first conductor groups comprises at least one conductor arranged along the circumferential direction of the stator core, the first connecting conductor comprises at least one layer of second conductor groups arranged along the axial direction of the stator core, and each layer of second conductor groups comprises at least two conductors arranged along the circumferential direction of the stator core; the second coil comprises a second in-slot conductor positioned in the stator tooth slot, a second circumferential conductor extending along the circumferential direction of the stator core and a second connecting conductor extending along the axial direction of the stator core, the second connecting conductor connects the second in-slot conductor and the second circumferential conductor, the second in-slot conductor comprises at least two layers of third conductor groups arranged along the circumferential direction of the stator core, each layer of third conductor groups comprises at least one conductor arranged along the radial direction of the stator core, the second circumferential conductor comprises at least one layer of fourth conductor groups arranged along the axial direction of the stator core, and each layer of fourth conductor groups comprises at least two conductors arranged along the radial direction of the stator core; the number of layers of the second conductor set is smaller than that of the first conductor set, and the number of layers of the fourth conductor set is smaller than or equal to that of the third conductor set.

According to the stator provided by the embodiment of the invention, the space perpendicular to the axial direction of the stator core can be fully utilized by reducing the number of layers of the second conductor set included in the first connecting conductor or the number of layers of the fourth conductor set included in the second circumferential conductor, the overall size of the stator winding in the axial direction of the stator core is reduced, the structure is more compact, the axial occupied space of the stator is reduced, and the motor is more miniaturized. The stator has the advantages of simple processing procedure, high manufacturing efficiency, high production qualification rate and the like.

In addition, the motor stator according to the above embodiment of the present invention may have the following additional technical features:

according to some embodiments of the invention, at least one of the conductors in the second conductor set includes a first extension segment and a second extension segment, the first extension segment connects the second extension segment and the first in-slot conductor, and the first extension segment extends along a circumferential direction of the stator core.

According to some embodiments of the invention, at least two of the conductors in the second conductor set comprise the first extension, the two first extensions extending away from each other in a direction away from the stator core.

According to some embodiments of the invention, the stator core includes a plurality of stator teeth, the stator tooth slots are formed between two adjacent stator teeth, and at least one conductor in the second conductor set at least partially overlaps with an axial projection of the stator teeth.

According to some embodiments of the invention, in the circumferential direction of the stator core, a width of an axially projected overlapping portion of the second conductor set and the stator teeth is L1, and a width of the stator teeth is L2, L1/L2 < 0.5.

According to some embodiments of the invention, the second conductor set is a plurality of layers, the plurality of layers comprising equal numbers of conductors.

According to some embodiments of the invention, the first circumferential conductor comprises at least one layer of fifth conductor set arranged along the axial direction of the stator core, each layer of fifth conductor set comprises at least two conductors arranged along the radial direction of the stator core, and the conductors of the first circumferential conductor are correspondingly connected with the conductors of the first connecting conductor.

According to some embodiments of the invention, the cross section of the conductor perpendicular to the length direction is rectangular, the first conductor set and the second conductor set are each arranged in a stacked manner along the length direction of the rectangle, and the third conductor set and the fourth conductor set are each arranged in a stacked manner along the width direction of the rectangle.

According to some embodiments of the invention, the stator core includes a plurality of stator teeth and an annular stator yoke, the plurality of stator teeth are provided on an inner circumferential surface or an outer circumferential surface of the stator yoke in a circumferential direction of the stator yoke, the first circumferential conductor is located axially outside the stator yoke, and the second circumferential conductor is located axially outside the stator teeth.

According to some embodiments of the invention, the second circumferential conductor is located on a side of the first circumferential conductor remote from the stator core in an axial direction of the stator core.

According to some embodiments of the invention, the stator winding comprises a multi-phase winding, each phase winding comprises a plurality of first coil groups and a plurality of second coil groups, the first coil groups and the second coil groups corresponding to the same phase are alternately arranged along the circumferential direction of the stator core, the first coil groups comprise a plurality of first coils which are concentrically arranged, the second coil groups comprise a plurality of second coils which are concentrically arranged, each phase winding comprises a plurality of parallel branches, and each branch is connected with a plurality of first coils of the first coil groups in series, and/or is connected with a plurality of second coils of the second coil groups in series.

According to some embodiments of the invention, a plurality of the conductors located in the same stator slot are connected in series.

According to some embodiments of the invention, the first coil and the second coil are preformed coils.

An electric machine according to an embodiment of the invention comprises a stator according to an embodiment of the invention.

A vehicle according to an embodiment of the invention includes an electric machine according to an embodiment of the invention.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

The foregoing and/or additional aspects and advantages of the invention will become apparent and may be better understood from the following description of embodiments taken in conjunction with the accompanying drawings in which:

fig. 1 is a schematic structural view of a stator according to an embodiment of the present invention;

FIG. 2 is an enlarged schematic view of the structure of FIG. 1 at circle A;

fig. 3 is an axial view of a stator core according to an embodiment of the present invention;

fig. 4 is a schematic structural view of one phase winding of a stator winding according to an embodiment of the present invention;

fig. 5 is a schematic view of the structure of a first coil according to an embodiment of the present invention;

fig. 6 is a schematic diagram of the structure of a second coil according to an embodiment of the present invention;

fig. 7 is a schematic structural view of another second coil according to an embodiment of the present invention;

FIG. 8 is a schematic view of the structure of a slot insulator according to an embodiment of the present invention;

fig. 9 is a schematic diagram of a vehicle according to an embodiment of the invention.

Reference numerals:

a stator 100; a motor 200; a vehicle 300;

a stator core 10; stator tooth slots 101; stator teeth 11; a stator yoke 12; a tooth shoe 13;

A stator winding 20; a conductor 21;

a first coil 30; a first in-slot conductor 31; a first conductor set 311; a first circumferential conductor 32; a fifth conductor set 321; a first connection conductor 33; a second conductor set 331; a first extension 332; a second extension 333;

a second coil 40; a second in-slot conductor 41; a third conductor set 411; a second circumferential conductor 42; a fourth conductor set 421; a second connection conductor 43; a sixth conductor set 431;

a first coil group 51; a second coil group 52;

slot insulator 60.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

In the description of the invention, "a first feature" may include one or more such features, and "a plurality" may mean two or more, and that a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, or may include both the first and second features not being in direct contact but being in contact with each other through additional features therebetween, with the first feature "above", "over" and "above" the second feature including both the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature.

A stator 100 according to an embodiment of the present invention is described below with reference to the accompanying drawings.

Referring to fig. 1 to 4, a stator 100 according to an embodiment of the present invention may include: a stator core 10 and stator windings 20.

Specifically, the stator core 10 has a plurality of stator slots 101, and the plurality of stator slots 101 may be arranged along the circumferential direction of the stator core 10. For example, as shown in fig. 1 to 3, the stator core 10 may include a stator yoke 12 and stator teeth 11, wherein the stator yoke 12 has a ring shape, the stator teeth 11 are plural, the plural stator teeth 11 are distributed along a circumferential direction of the stator yoke 12 and are provided on an inner circumferential surface of the stator yoke 12 for the inner rotor motor 200, in other words, each stator tooth 11 is connected with the inner circumferential surface of the stator yoke 12 along an outer end of the stator core 10 in a radial direction, and inner ends of the plural stator teeth 11 may define a stator hole coaxial with the stator yoke 12. Alternatively, a plurality of stator teeth 11 are provided on the outer peripheral surface of the stator yoke 12 for the outer rotor motor 200, in other words, each stator tooth 11 is connected to the outer peripheral surface of the stator yoke 12 along the inner end in the radial direction of the stator core 10. And stator tooth slots 101 are formed between adjacent two stator tooth portions 11. In some embodiments, the stator teeth 11 may be integrally formed with the stator yoke 12.

As shown in fig. 1-2 and 4-6, the stator winding 20 includes a first coil 30 and a second coil 40.

The first coil 30 includes a first in-slot conductor 31, a first circumferential conductor 32, and a first connection conductor 33, where the first in-slot conductor 31 is located in the stator slot 101, the first circumferential conductor 32 extends along the circumference of the stator core 10, the first connection conductor 33 extends along the radial direction of the stator core 10, and the first connection conductor 33 connects the first in-slot conductor 31 and the first circumferential conductor 32, so that the first coil 30 forms an annular structure.

Specifically, as shown in fig. 1 and 4 to 5, the first coil 30 includes two first in-slot conductors 31, two first circumferential conductors 32, and four first connecting conductors 33, and both ends of each first circumferential conductor 32 are connected to ends of the two first in-slot conductors 31 through one first connecting conductor 33, respectively.

Further, the first in-slot conductor 31 includes at least two layers of first conductor groups 311 arranged in the radial direction of the stator core 10, each layer of first conductor groups 311 including one conductor 21 or a plurality of conductors 21 arranged in the circumferential direction of the stator core 10, the first connection conductor 33 includes at least one layer of second conductor groups 331 arranged in the axial direction of the stator core 10, and each layer of second conductor groups 331 includes at least two conductors 21 arranged in the circumferential direction of the stator core 10.

By extending the first connection conductor 33 in the radial direction of the stator core 10, the first circumferential conductor 32 can be arranged offset with respect to the first in-slot conductor 31 in the radial direction of the stator core 10. In winding the first coil 30, the conductor 21 of the first in-slot conductor 31 may be bent outward in the radial direction of the stator core 10 to wind one of the conductors 21 of the first connection conductor 33, then bent in the circumferential direction of the stator core 10 to wind one of the conductors 21 of the first circumferential conductor 32, and then bent inward in the radial direction of the stator core 10. In the whole winding process, the first in-groove conductor 31, the first connecting conductor 33 and the first circumferential conductor 32 can be obtained by bending and winding one wire, or all the conductors 21 of the first in-groove conductor 31, the first connecting conductor 33 and the first circumferential conductor 32 can be formed by bending and winding the same wire, so that the processes of twisting, flaring and the like of the hairpin winding are omitted, the complexity of the process is greatly reduced, the manufacturing efficiency is improved, and the conductors 21 in the first in-groove conductor 31, the first connecting conductor 33 and the first circumferential conductor 32 can be orderly arranged, so that the qualification rate and the performance of the stator 100 can be remarkably improved.

As shown in fig. 1-2, 4 and 6-7, the second coil 40 includes a second in-slot conductor 41, a second circumferential conductor 42, and a second connection conductor 43. The second in-slot conductor 41 is located in the stator slot 101, the second circumferential conductor 42 extends along the circumferential direction of the stator core 10, the second connection conductor 43 extends along the axial direction of the stator core 10, and the second connection conductor 43 connects the second in-slot conductor 41 and the second circumferential conductor 42 so that the second coil 40 forms an annular structure.

Specifically, the second coil 40 includes two second in-slot conductors 41, two second circumferential conductors 42, and four second connection conductors 43, and both ends of each second circumferential conductor 42 are connected to ends of the two second in-slot conductors 41 through one second connection conductor 43, respectively.

Further, the second in-slot conductor 41 includes at least two layers of third conductor groups 411 arranged in the circumferential direction of the stator core 10, each layer of third conductor groups 411 including one conductor 21 or a plurality of conductors 21 arranged in the radial direction of the stator core 10, the second circumferential conductor 42 includes at least one layer of fourth conductor groups 421 arranged in the axial direction of the stator core 10, and each layer of fourth conductor groups 421 includes at least two conductors 21 arranged in the radial direction of the stator core 10.

The second connection conductor 43 extends in the axial direction of the stator core 10, so that the second circumferential conductor 42 can be arranged offset with respect to the second in-slot conductor 41 in the axial direction of the stator core 10. In a state where the first coil 30 and the second coil 40 are simultaneously mounted to the stator core 10, it is advantageous to make the first circumferential conductor 32 and the second circumferential conductor 42 at least partially stagger in both the axial direction and the radial direction of the stator core 10, thereby facilitating more compact arrangement of the stator winding 20 on the stator core 10 and reducing the occupied space.

When winding the second coil 40, the conductor 21 of the second in-slot conductor 41 may be extended out of the stator slot 101 in the axial direction of the stator core 10 to wind one of the conductors 21 of the second connection conductor 43, then bent in the circumferential direction of the stator core 10 to wind one of the conductors 21 of the second circumferential conductor 42, and then bent toward the stator slot 101 in the axial direction of the stator core 10. In the whole winding process, the conductors 21 of the second groove inner conductor 41, the second connecting conductor 43 and the second circumferential conductor 42 which are positioned on the same layer can be obtained through bending and winding one wire, or all the conductors 21 of the second groove inner conductor 41, the second connecting conductor 43 and the second circumferential conductor 42 can be formed through bending and winding the same wire, so that the working procedures of twisting, flaring and the like of the hairpin winding are omitted, the complexity of working procedures is greatly reduced, the manufacturing efficiency is improved, and a plurality of conductors 21 in the second groove inner conductor 41, the second connecting conductor 43 and the second circumferential conductor 42 can be orderly arranged, so that the qualification rate and the performance of the stator 100 can be remarkably improved.

In the embodiment of the present invention, as shown in fig. 1 to 7, the number of layers of the second conductor set 331 is smaller than that of the first conductor set 311, and when the conductor 21 of the first coil 30 extends from the stator slot 101 and is bent radially along the stator core 10 during the winding process, more layers of the first conductor 31 in the slot are adjusted to be fewer layers of the first connecting conductor 33. Therefore, the dimension of the first connection conductor 33 along the axial direction of the stator core 10 is smaller than the dimension of the first in-slot conductor 31 along the radial direction of the stator core 10, and compared with the dimension of the stator winding 20 along the axial direction of the stator core 10 without adjusting the number of layers of the conductor sets, the dimension of the stator winding 20 is effectively reduced, the structure of the stator winding 20 is more compact, and the overall occupied space of the stator 100 is reduced.

For example, in the example shown in fig. 2, 4 to 5, the first in-slot conductor 31 of the first coil 30 includes 4 layers of the first conductor sets 311 arranged in the radial direction of the stator core 10, and each layer of the first conductor sets 311 includes 2 conductors 21 arranged in the circumferential direction of the stator core 10. When the first in-slot conductor 31 extends out of the stator slot 101 and is bent in the radial direction of the stator core 10 to form the first connection conductor 33, if the number of layers of the conductor sets is not adjusted, the first connection conductor 33 includes 4 layers of the second conductor sets 331 axially arranged along the stator core 10, which results in a larger occupied axial space. By adjusting the number of layers of the conductor sets, the number of layers of the second conductor set 331 is reduced, as shown in fig. 4-5, which is 2 layers, the number of conductors 21 included in each layer of the second conductor set 331 is increased, and the space perpendicular to the axial direction of the stator core 10 is reasonably utilized, so as to reduce the axial dimension of the stator core 10.

It should be noted that, in the embodiment in which the second conductor set 331 is a plurality of layers, the number of the conductors included in the plurality of layers of the second conductor set 331 may be equal or unequal. In the embodiment in which the number of the conductors included in the multi-layer second conductor set 331 is equal, as shown in fig. 4 to 5, not only the axial occupied space of the first connecting conductor 33 can be reduced, but also the excessive occupied space in the direction perpendicular to the axis of the stator core 10 can be avoided, interference with other conductors 21 or structures can be avoided, and the structural design is more reasonable.

In addition, the number of layers of the fourth conductor set 421 is less than or equal to the number of layers of the third conductor set 411. In the embodiment in which the number of layers of the fourth conductor set 421 is equal to the number of layers of the third conductor set 411, as shown in fig. 2 and 6 to 7, the dimension of the second circumferential conductor 42 in the axial direction of the stator core 10 is equal to the dimension of the second in-slot conductor 41 in the circumferential direction of the stator core 10. In the embodiment in which the number of layers of the fourth conductor set 421 is smaller than that of the third conductor set 411, in the winding process, when the conductor 21 of the second coil 40 extends from the stator slot 101 and is bent along the circumferential direction of the stator core 10, more layers of the second in-slot conductor 41 are adjusted to be fewer layers of the second circumferential conductor 42, so that the dimension of the second circumferential conductor 42 along the axial direction of the stator core 10 is smaller than that of the second in-slot conductor 41 along the circumferential direction of the stator core 10, and compared with the case that the number of layers of the conductor sets is not adjusted, the dimension of the whole stator winding 20 along the axial direction of the stator core 10 is effectively reduced, the structure of the stator winding 20 is more compact, and the occupied space of the whole stator 100 is reduced.

The number of layers of the fourth conductor set 421 may be flexibly set according to the number of conductors included in the second coil 40, the arrangement of the conductors 21, and the size of the stator core 10.

For example, as shown in fig. 6 to 7, the second coil 40 includes 8 conductors 21, that is, the second slot conductor 41 includes 8 conductors 21, the second circumferential conductor 42 includes 8 conductors 21, among the second slot conductors 41, the 8 conductors 21 are arranged in 2 layers of the third conductor group 411 along the axial direction of the stator core 10, each layer of the third conductor group 411 includes 4 conductors 21 arranged along the radial direction of the stator core 10, that is, the number of conductors arranged along the radial direction of the stator core 10 in the second slot conductor 41 is greater than the number of conductors arranged along the circumferential direction, and when the second slot conductor 41 extends out of the stator slot 101 and is then bent along the circumferential direction, the number of layers of the formed fourth conductor group 421 is small even if the number of layers of the conductor group is not adjusted, and thus the number of layers of the fourth conductor group 421 can be equal to the number of layers of the third conductor group 411.

Of course, in order to further reduce the axial dimension of the stator winding 20, the number of layers of the fourth conductor set 421 may be reduced, so that the 8 conductors 21 are rearranged, for example, the fourth conductor set 421 is 1 layer and includes 8 conductors 21 radially arranged along the stator core 10, and the space perpendicular to the axial direction of the stator core 10 is reasonably utilized, so as to reduce the axial dimension of the stator core 10.

In addition, in the embodiment of the present invention, reducing the number of layers of the second conductor set 331 is also beneficial to increasing the exposed area of the first connection conductor 33, increasing the heat dissipation area, and reducing the axial heat conduction distance; similarly, reducing the number of layers of the fourth conductor set 421 is beneficial to increasing the exposed area of the second circumferential conductor 42, increasing the heat dissipation area, and reducing the axial heat conduction distance, thereby improving the overall heat dissipation effect of the stator winding 20.

According to the stator 100 of the embodiment of the present invention, by reducing the number of layers of the second conductor set 331 included in the first connection conductor 33 or reducing the number of layers of the fourth conductor set 421 included in the second circumferential conductor 42, the space perpendicular to the axial direction of the stator core 10 can be fully utilized, the overall size of the stator winding 20 in the axial direction of the stator core 10 can be reduced, the structure is more compact, the axial occupation space of the stator 100 can be reduced, the motor 200 can be more miniaturized, the heat dissipation area can be increased, and the heat dissipation effect can be improved. And the stator 100 has the advantages of simple processing procedure, high manufacturing efficiency, high production qualification rate and the like.

According to some embodiments of the present invention, as shown in fig. 2 and 5, at least one conductor 21 in the second conductor set 331 includes a first extension 332 and a second extension 333. Wherein the first extension 332 connects the second extension 333 and the second in-slot conductor 41, and the first extension 332 extends in the circumferential direction of the stator core 10.

Thus, by adjusting the extension length or the extension direction of the first extension 332, the position of the second extension 333 connected to the first extension 332 in the circumferential direction of the stator core 10 can be adjusted. The plurality of conductors 21 can be arranged in the circumferential direction of the stator core 10 by adjusting the extension dimension or the extension direction of the first extension 332 of the plurality of conductors 21, or the conductors 21 including the first extension 332 and the conductors 21 not including the first extension 332 can be arranged in the circumferential direction of the stator core 10.

For example, in two adjacent first conductor sets 311, the conductor 21 included in one first conductor set 311 may be connected to the first extension 332, so that the correspondingly connected second extension 333 may be located in the same second conductor set 331 as the conductor 21 connected to the other first conductor set 311, thereby reducing the number of conductor sets of the second conductor set 331 arranged in the axial direction of the stator core 10.

In some embodiments, as shown in fig. 2 and 5, in the second conductor set 331, at least two conductors 21 include first extension sections 332, and the two first extension sections 332 extend away from each other in a direction away from the stator core 10. For example, in fig. 2, the two first extension sections 332 extend away from each other from bottom to top, so that a certain gap is formed between the two connected second extension sections 333, and the gap may be used to arrange other conductors 21, so that the second conductor set 331 can include more conductors 21 arranged along the circumference of the stator core 10, and avoid that the second conductor set 331 is too far from being offset on the stator core 10 relative to the corresponding stator slot 101, so as to affect the winding uniformity of the stator winding 20.

For example, in the example shown in fig. 2, 4 to 5, the first in-slot conductor 31 includes 4 layers of the first conductor set 311, and the 1 st, 2 nd, 3 rd and 4 th layers are sequentially arranged from inside to outside in the radial direction of the stator slot 101, and each layer of the first conductor set 311 includes 2 conductors 21. Among the first connection conductors 33, the conductors 21 connected to the 1 st layer first conductor set 311 and the 3 rd layer first conductor set 311 each include a first extension 332 and a second extension 333, and the conductors 21 connected to the 2 nd layer first conductor set 311 and the 4 th layer first conductor set 311 each do not include the first extension 332 and directly extend by bending outward in the radial direction of the stator core 10. Thus, the two conductors 21 connected to the 1 st layer first conductor set 311 and the two conductors 21 connected to the 2 nd layer first conductor set 311 can constitute one layer second conductor set 331, the two conductors 21 connected to the 3 rd layer first conductor set 311 and the two conductors 21 connected to the 4 th layer first conductor set 311 can constitute another layer second conductor set 331, and the number of layers of the second conductor set 331 is reduced.

In some embodiments, as shown in fig. 1 to 3, the stator core 10 includes a plurality of stator teeth 11, and stator slots 101 are formed between adjacent two of the stator teeth 11. In the second conductor set 331, at least one conductor 21 at least partially overlaps the axial projection of the stator tooth 11. For example, the conductors 21 located at both ends of the second conductor group 331 in the circumferential direction of the stator core 10 overlap with the circumferential projection of the stator tooth 11, that is, the second conductor group 331 crosses the line from the axial side space of the stator tooth 11, so that the space perpendicular to the axial direction of the stator core 10 can be more fully utilized, the height of the end portions of the stator winding 20 can be reduced, and the motor 200 can be more miniaturized.

In some embodiments, the width of the overlapping portion of the axial projection of the second conductor set 331 and the stator tooth 11 in the circumferential direction of the stator core 10 is L1, the width of the stator tooth 11 in the circumferential direction of the stator core 10 is L2, and L1/L2 < 0.5. That is, the first connection conductor 33 is bent to the conductor 21 in the space on one axial side of the stator tooth 11, and the bending range is not more than half the width of the stator tooth 11, so as to avoid the interference of the positions of the first connection conductors 33 corresponding to the adjacent stator tooth slots 101 and also avoid the electromagnetic interference.

In some embodiments in which the number of layers of the fourth conductor set 421 is smaller than the number of layers of the third conductor set 411, at least one conductor 21 in the second circumferential conductor 42 includes a third extension and a fourth extension, wherein the third extension connects the fourth extension and the second connection conductor 43, and the third extension extends in the radial direction of the stator core 10. By adjusting the extension length or the extension direction of the third extension section, the position of the fourth extension section connected to the third extension section in the radial direction of the stator core 10 can be adjusted. By adjusting the extension dimension or the extension direction of the third extension section, the plurality of conductors 21 can be arranged in the radial direction of the stator core 10, or the conductors 21 including the third extension section and the conductors 21 not including the third extension section can be arranged in the radial direction of the stator core 10.

In other embodiments, as shown in fig. 1 to 2 and 6, the second connection conductor 43 includes a plurality of layers of sixth conductor groups 431 arranged along the circumferential direction of the stator core 10, and the sixth conductor groups 431 include a plurality of conductors 21 arranged along the radial direction of the stator core 10. In the second connection conductor 43, at least one conductor 21 may include a fifth extension and a sixth extension, the fifth extension connecting the second in-slot conductor 41 and the sixth extension, and the fifth extension extending in the radial direction of the stator core 10, so that the conductors 21 of the second connection conductor 43 may be arranged in one layer of conductor groups in the radial direction of the stator core 10, or the conductors 21 including the fifth extension and the conductors 21 not including the fifth extension may be arranged in the same layer of conductor groups in the radial direction of the stator core 10. Thus, the number of layers of the sixth conductor group 431 included in the second connection conductor 43 is smaller than the number of layers of the third conductor group 411 included in the second in-slot conductor 41, so that the number of layers of the fourth conductor group 421 included in the second circumferential conductor 42 connected to the second connection conductor 43 is smaller than the number of layers of the third conductor group 411 included in the second in-slot conductor 41.

According to some embodiments of the present invention, as shown in fig. 2 and fig. 4-5, the number of the conductor sets included in the first circumferential conductor 32 may be equal to the number of the conductor sets included in the first connection conductor 33, so that the dimension of the portion of the first coil 30 located outside the stator slot 101 along the axial direction of the stator core 10 is smaller, which is more beneficial to reducing the axial occupied space of the stator winding 20.

In some embodiments, as shown in fig. 2 and fig. 4 to fig. 5, the first circumferential conductor 32 includes at least one layer of fifth conductor set 321 arranged along the axial direction of the stator core 10, each layer of fifth conductor set 321 includes at least two conductors 21 arranged along the radial direction of the stator core 10, and the conductors 21 of the first circumferential conductor 32 are correspondingly connected with the conductors 21 of the first connection conductor 33, that is, the first circumferential conductor 32 and the first connection conductor 33 include equal numbers of conductors and are arranged in corresponding positions. During the winding, the conductor 21 passing through the first connection conductor 33 is bent in the circumferential direction of the stator core 10 to obtain the conductor 21 of the first circumferential conductor 32.

In some embodiments of the present invention, as shown in fig. 1 to 7, the cross section of the conductor 21 perpendicular to the length direction is rectangular, in other words, the conductor 21 is a flat wire.

The first conductor sets 311 are stacked along the length direction of the rectangle, so that the first conductors 31 in the slots can more easily pass through the slots of the stator slots 101 in the process of loading the stator slots 101, and the slot size of the stator slots 101 can be designed smaller, so as to reduce tooth harmonics, improve magnetic circuits and reduce local magnetic density supersaturation. The second conductor sets 331 are arranged in a stacked manner along the length direction of the rectangle, the number of layers of the conductor sets is small, the axial dimension is reduced, the heat dissipation effect is improved, the bending structure of the conductor 21 can be simplified, and the processing technology difficulty is reduced.

The third conductor sets 411 are arranged in a stacked manner in the width direction of the rectangle, making it easier for the second in-slot conductors 41 to pass through the slots of the stator slot 101 during the insertion into the stator slot 101. The fourth conductor group 421 is arranged in a stacked manner in the width direction of the rectangle, which is more advantageous in increasing the surface area of the second circumferential conductor 42 and reducing the axial dimension, while simplifying the bent structure of the conductor 21.

In some embodiments in which the stator core 10 includes the stator teeth 11 and the stator yoke 12, as shown in fig. 1-7, the first circumferential conductor 32 is located axially outward of the stator yoke 12 and the second circumferential conductor 42 is located axially outward of the stator teeth 11. In other words, the projection of the first circumferential conductor 32 in the axial direction of the stator core 10 falls within the projection range of the stator yoke 12, and the projection of the second circumferential conductor 42 in the axial direction of the stator core 10 is located in the region between the stator yoke 12 and the stator hole. Therefore, the first circumferential conductors 32 of the first coil 30 and the second circumferential conductors 42 of the second coil 40 are staggered along the radial direction of the stator core 10, so that the arrangement requirements of the first coil 30 and the second coil 40 are met, interference is avoided, and the installation is convenient.

In some embodiments, as shown in fig. 1-7, the second circumferential conductor 42 is located on a side of the first circumferential conductor 32 away from the stator core 10 in the axial direction of the stator core 10, so that the first circumferential conductor 32 and the second circumferential conductor 42 are staggered in the axial direction of the stator core 10, thereby meeting the arrangement requirement of the first coil 30 and the second coil 40 and avoiding interference.

In the assembly process, a plurality of first coils 30 may be first installed in the corresponding stator tooth slots 101, so that two first circumferential conductors 32 of each first coil 30 are respectively located at two axial sides of the stator yoke 12, and the first circumferential conductors 32 are in clearance fit with the stator yoke 12; then, a plurality of second coils 40 are installed in the corresponding stator slots 101, so that two second circumferential conductors 42 of each second coil 40 are respectively located at two axial sides of the stator tooth 11, and the second circumferential conductors 42 are located at the outer side (i.e. the side far away from the stator core 10) of the first connection conductor 33 of the first coil 30, and the assembly of the first coil 30 does not affect the assembly of the second coils 40, so that the structure is reasonable and orderly.

In some embodiments of the present invention, as shown in fig. 1-7, the stator winding 20 comprises a multi-phase winding, each phase winding comprising a plurality of first coil groups 51 and a plurality of second coil groups 52, the plurality being two or more. Wherein, all the first coil groups 51 are sequentially arranged along the circumference of the stator core 10 in a multi-phase predetermined order, all the second coil groups 52 are sequentially arranged along the circumference of the stator core 10 in a multi-phase predetermined order, and the first coil groups 51 and the second coil groups 52 corresponding to the same phase are alternately arranged along the circumference of the stator core 10. Also, each first coil group 51 may include at least one first coil 30, and each second coil group 52 includes at least one second coil 40.

Through setting up the first coil group 51 and the second coil group 52 of two kinds of different structures, can satisfy stator winding 20's assembly demand, first coil group 51 and second coil group 52 suitability is strong, and coil kind quantity is few, is favorable to reducing the degree of difficulty of prefabricated coil, improves production efficiency.

For example, as shown in fig. 1 to 4, the stator winding 20 includes six first coil groups 51 and six second coil groups 52, and the stator winding 20 includes a three-phase winding of a phase, B phase, and C phase, each phase including two first coil groups 51 and two second coil groups 52. The six first coil groups 51 are sequentially arranged in the order of phase a, phase B, phase C, phase a, phase B and phase C, the six second coil groups 52 are sequentially arranged in the order of phase a, phase B, phase C, phase a, phase B and phase C, each first coil group 51 includes two first coils 30 arranged concentrically, and each second coil group 52 also includes two second coils 40 arranged concentrically. The first coil groups 51 and the second coil groups 52 corresponding to the same phase are alternately arranged, that is, the first coil groups 51, the second coil groups 52 are sequentially arranged in this order.

In the embodiment in which the coil group (the first coil group 51 or the second coil group 52) includes the plurality of coils (the first coil 30 or the second coil 40), the difference between the slot span of the outer ring coil and the slot span of the inner ring coil is 2 in the two adjacent coils arranged concentrically, so that the plurality of coils are mounted on the stator core 10 without interference, and the damage to the coils is avoided.

In addition, the plurality of first coil groups 51 and the plurality of second coil groups 52 are staggered by a preset angle which is half of the corresponding central angle of the first coil groups 51, so that two adjacent second in-slot conductors 41 of the second coil groups 52 are positioned in the stator tooth slots 101 in the area surrounded by the same first coil groups 51, and two adjacent first in-slot conductors 31 of each first coil group 51 are positioned in the stator tooth slots 101 in the area surrounded by the same second coil groups 52.

In the embodiment in which the first coil group 51 includes two first coils 30 and the second coil group 52 includes two second coils 40, the adjacent pair of inner-ring first-slot conductors 31 and outer-ring first-slot conductors 31 of the first coil group 51 are located between the two inner-ring second-slot conductors 41 of the second coil group 52, and the adjacent pair of inner-ring second-slot conductors 41 and outer-ring second-slot conductors 41 of the second coil group 52 are located between the two inner-ring first-slot conductors 31 of the first coil group 51. For example, the numbers of the stator slots 101 corresponding to the four first in-slot conductors 31 of the first coil set 51 may be No. 1, no. 2, no. 7, and No. 8, and the numbers of the stator slots 101 corresponding to the four second in-slot conductors 41 of the second coil set 52 may be No. 5, no. 6, no. 11, and No. 12.

In some embodiments, as shown in fig. 1-4, the first coil group 51 includes a plurality of first coils 30 arranged concentrically, i.e., an inner ring first coil 30 and an outer ring first coil 30; the second coil group 52 includes a plurality of second coils 40, i.e., an inner ring second coil 40 and an outer ring second coil 40, which are concentrically arranged. Each phase winding comprises a plurality of branches connected in parallel, and each branch is connected in series with only two first coils 30 of the first coil group 51, with only two second coils 40 of the second coil group 52, or with both two first coils 30 of the first coil group 51 and two second coils 40 of the second coil group 52. Therefore, each branch forms a non-whole-circle arrangement structure, more parallel branches are formed, application requirements of low-voltage working conditions are met, and resistance differences between the two first coils 30 and between the two second coils 40 can be balanced through connecting the two first coils 30 positioned in the same first coil group 51 or the two second coils 40 positioned in the same second coil group 52 in series, so that performance of the stator 100 is improved.

Specifically, each phase winding includes two first coil groups 51 (denoted as 1# first coil group 51 and 2# first coil group 51) and two second coil groups 52 (denoted as 1# second coil group 52 and 2# second coil group 52), which are arranged in the order of 1# first coil group 51, 1# second coil group 52, 2# first coil group 51, 2# second coil group 52 in the circumferential direction of the stator core 10.

In some embodiments, each phase winding constitutes two branches in parallel. One of the branches is connected in series with the inner ring first coil 30 and the outer ring first coil 30 of the 1# first coil group 51, and the inner ring second coil 40 and the outer ring second coil 40 of the 1# second coil group 52, and the other branch is connected in series with the inner ring first coil 30 and the outer ring first coil 30 of the 2# first coil group 51, and the inner ring second coil 40 and the outer ring second coil 40 of the 2# second coil group 52.

In other embodiments, each phase winding comprises four branches in parallel. The first branch is connected in series with the inner ring first coil 30 and the outer ring first coil 30 of the 1# first coil group 51, the second branch is connected in series with the inner ring second coil 40 and the outer ring second coil 40 of the 1# second coil group 52, the third branch is connected in series with the inner ring first coil 30 and the outer ring first coil 30 of the 2# first coil group 51, and the fourth branch is connected in series with the inner ring second coil 40 and the outer ring second coil 40 of the 2# second coil group 52.

In some embodiments, a plurality of conductors 21 located in the same stator slot 101 are connected in series, i.e. a plurality of conductors 21 located in the same layer are connected in series, and groups of the plurality of layers of conductors 21 are also connected in series, so that the conductors 21 located in the same stator slot 101 form a series branch, and the connected connection conductors 21 and circumferential conductors 21 are also connected in series in the branch. Thus, each of the first coils 30 (or the second coils 40) can be made to have a winding effect of a plurality of wires, thereby contributing to an increase in the series magnetic flux potential of the stator winding 20 and to an increase in torque.

It should be noted that, the plurality of conductors 21 in the same stator slot 101 may be formed by winding the same wire, which is beneficial to simplifying the production process and improving the production efficiency, or the plurality of conductors 21 may be formed by winding different wires, and the wound conductors 21 may be welded to form a series structure, for example, the plurality of conductors 21 located in the same layer may be formed by winding the same wire, after each layer of conductor 21 obtained by winding is assembled into the stator core 10, the plurality of layers of conductors 21 are welded to form a series structure, thereby not only meeting the performance requirements of improving the torque and the like, but also further reducing the installation difficulty of the stator winding 20 in the stator core 10 and improving the assembly efficiency.

In some embodiments, the first coil 30 and the second coil 40 may be prefabricated coils, and the stator core 10 is assembled after the prefabrication, the winding process of the first coil 30 and the second coil 40 is not limited by the smaller space of the stator core 10, and the position arrangement and the bending direction of the plurality of conductors 21 in the winding process are easy to control, so that the winding efficiency and the qualification rate are improved, and the requirements of changing the number of conductors and the number of conductor groups at different positions of different stators 100 are met.

According to some embodiments of the present invention, as shown in fig. 2 and 8, the stator 100 may further include slot insulators 60, and the first in-slot portions of the first coil 30 and the second in-slot portions of the second coil 40 may be disposed in the slot insulators 60 in the corresponding stator slots 101 to achieve an insulation effect with the stator core 10 through the slot insulators 60.

According to some embodiments of the present invention, as shown in fig. 2 and 3, each stator slot 101 has two first inner sides opposite to each other, the slot of the stator slot 101 has two second inner sides opposite to each other, the two second inner sides are spaced apart from the adjacent first inner sides by L3 and L4, respectively, and L3 > L4, such that the slot is formed in an asymmetric structure with respect to the stator slot 101.

For example, in some embodiments, as shown in fig. 2 and 3, an end of one of the first inner sides (e.g., the corresponding inner end of the inner rotor motor 200, or the corresponding outer end of the outer rotor motor 200) is provided with a tooth shoe 13, the end of the tooth shoe 13 being formed into the second inner side; the other first inner side is provided with no tooth shoe 13 at its end, the first inner side being coplanar with the second inner side, the tooth shoe 13 and the other first inner side forming a slot of the stator slot 101 therebetween. Whereby the corresponding shoes 13 of each stator slot 101 are formed in an asymmetric structure and the width of the slot of the stator slot 101 is smaller than the slot width of the stator slot 101. In other words, of the two sides of the adjacent two stator teeth 11 opposite to each other, one side is provided with the tooth shoe 13 and the other side is not provided with the tooth shoe 13, so that the notch of the stator tooth slot 101 is formed between the tooth shoe 13 and the side where the tooth shoe 13 is not provided.

In other embodiments, the ends of the two first inner sides of the stator slot 101 (such as the corresponding inner ends of the inner rotor motor 200 or the corresponding outer ends of the outer rotor motor 200) are provided with the tooth shoes 13, and the extending dimensions of the two tooth shoes 13 along the circumferential direction of the stator core 10 are not equal, and the sides of the two tooth shoes 13 opposite to each other are formed as the second inner sides. Thereby forming an asymmetric tooth shoe 13 structure.

The asymmetric notch structure can effectively reduce the notch size of the stator tooth slot 101, is favorable for improving torque, reduces an air gap, is lighter in harmonic wave, and therefore is favorable for improving NVH performance, reducing noise and reducing iron loss of the stator core 10. In addition, the asymmetric notch structure can ensure that the first in-slot conductor 31 and the second in-slot conductor 41 can be smoothly arranged in the stator tooth slot 101 while reducing the size of the notch as much as possible, and compared with the complex procedure of the hairpin winding, the assembly process difficulty is greatly reduced, the assembly requirements of a plurality of conductor group layers can be met, the motor 200 requirements of different working conditions or different application environments are met, the manufacturing efficiency of the stator 100 is improved, and the production qualification rate is improved.

As shown in fig. 9, the motor 200 according to the embodiment of the present invention includes the stator 100 according to the embodiment of the present invention. Since the stator 100 according to the embodiment of the present invention has the above-described advantageous technical effects, according to the motor 200 of the embodiment of the present invention, by reducing the number of layers of the second conductor set 331 included in the first connection conductor 33 or the number of layers of the fourth conductor set 421 included in the second circumferential conductor 42, the space perpendicular to the axial direction of the stator core 10 can be fully utilized, the overall size of the stator winding 20 in the axial direction of the stator core 10 can be reduced, the structure can be more compact, the axial occupation space of the stator 100 can be reduced, the motor 200 can be more miniaturized, the heat dissipation area can be increased, and the heat dissipation effect can be improved. And the stator 100 has the advantages of simple processing procedure, high manufacturing efficiency, high production qualification rate and the like.

As shown in fig. 9, a vehicle 300 according to an embodiment of the present invention includes a motor 200 according to an embodiment of the present invention. Since the motor 200 according to the embodiment of the present invention has the above advantageous technical effects, according to the vehicle 300 of the embodiment of the present invention, by reducing the number of layers of the second conductor set 331 included in the first connection conductor 33 or the number of layers of the fourth conductor set 421 included in the second circumferential conductor 42, the space perpendicular to the axial direction of the stator core 10 can be fully utilized, the overall size of the stator winding 20 in the axial direction of the stator core 10 can be reduced, the structure can be more compact, the axial occupation space of the stator 100 can be reduced, the motor 200 can be more miniaturized, the heat dissipation area can be increased, and the heat dissipation effect can be improved. And the stator 100 has the advantages of simple processing procedure, high manufacturing efficiency, high production qualification rate and the like.

In some embodiments, the number of slots of the stator slots 101 is 48, and the number of pole pairs corresponding to the stator 100 is 6, so that the stator 100 better meets the application requirements of the driving motor 200 of the automobile.

Here, the vehicle 300 may be a new energy vehicle, and in some embodiments, the new energy vehicle may be a pure electric vehicle 300 having the motor 200 as a main driving force, and in other embodiments, the new energy vehicle 300 may be a hybrid vehicle having both the internal combustion engine and the motor 200 as main driving forces. Regarding the internal combustion engine and the motor 200 that supply driving power to the new energy vehicle mentioned in the above embodiments, the internal combustion engine may use gasoline, diesel oil, hydrogen gas, or the like as fuel, and the manner of supplying electric power to the motor 200 may use a power battery, a hydrogen fuel cell, or the like, without being particularly limited thereto. The present invention is not limited to the above-described embodiments, and may be applied to any other embodiments.

Other configurations and operations of the vehicle 300 and the motor 200 according to the embodiment of the present invention are known to those of ordinary skill in the art and will not be described in detail herein.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

In the description herein, reference to the terms "embodiment," "specific embodiment," "example," and the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims (15)

1. A stator, comprising:

a stator core having a plurality of stator slots;

a stator winding including a first coil and a second coil;

the first coil comprises a first in-slot conductor positioned in the stator tooth slot, a first circumferential conductor extending along the circumferential direction of the stator core and a first connecting conductor extending along the radial direction of the stator core, the first connecting conductor connects the first in-slot conductor and the first circumferential conductor, the first in-slot conductor comprises at least two layers of first conductor groups arranged along the radial direction of the stator core, each layer of first conductor groups comprises at least one conductor arranged along the circumferential direction of the stator core, the first connecting conductor comprises at least one layer of second conductor groups arranged along the axial direction of the stator core, and each layer of second conductor groups comprises at least two conductors arranged along the circumferential direction of the stator core;

The second coil comprises a second in-slot conductor positioned in the stator tooth slot, a second circumferential conductor extending along the circumferential direction of the stator core and a second connecting conductor extending along the axial direction of the stator core, the second connecting conductor connects the second in-slot conductor and the second circumferential conductor, the second in-slot conductor comprises at least two layers of third conductor groups arranged along the circumferential direction of the stator core, each layer of third conductor groups comprises at least one conductor arranged along the radial direction of the stator core, the second circumferential conductor comprises at least one layer of fourth conductor groups arranged along the axial direction of the stator core, and each layer of fourth conductor groups comprises at least two conductors arranged along the radial direction of the stator core;

the number of layers of the second conductor set is smaller than that of the first conductor set, and the number of layers of the fourth conductor set is smaller than or equal to that of the third conductor set.

2. The stator of claim 1, wherein at least one of the conductors in the second conductor set includes a first extension segment and a second extension segment, the first extension segment connecting the second extension segment and the first in-slot conductor, the first extension segment extending in a circumferential direction of the stator core.

3. The stator of claim 2, wherein at least two of the conductors in the second conductor set include the first extension, the two first extensions extending away from each other in a direction away from the stator core.

4. The stator of claim 1, wherein the stator core includes a plurality of stator teeth, the stator tooth slots being formed between two adjacent stator teeth, at least one of the conductors in the second conductor set at least partially overlapping an axial projection of the stator teeth.

5. The stator according to claim 4, wherein a width of an axially projected overlapping portion of the second conductor set and the stator teeth in a circumferential direction of the stator core is L1, and a width of the stator teeth is L2, L1/L2 < 0.5.

6. The stator of claim 1, wherein the second conductor set is a plurality of layers, the plurality of layers comprising equal numbers of conductors.

7. The stator as claimed in claim 1, wherein,

the first circumferential conductor comprises at least one layer of fifth conductor set which is axially arranged along the stator core, each layer of fifth conductor set comprises at least two conductors which are radially arranged along the stator core, and the conductors of the first circumferential conductor are correspondingly connected with the conductors of the first connecting conductor.

8. The stator according to claim 1, wherein a cross section of the conductor perpendicular to a length direction is rectangular, the first conductor set and the second conductor set are each arranged in a stacked manner in the length direction of the rectangle, and the third conductor set and the fourth conductor set are each arranged in a stacked manner in a width direction of the rectangle.

9. The stator according to claim 1, wherein the stator core includes a plurality of stator teeth and an annular stator yoke, the plurality of stator teeth being provided on an inner peripheral surface or an outer peripheral surface of the stator yoke in a circumferential direction of the stator yoke, the first circumferential conductor being located axially outward of the stator yoke, and the second circumferential conductor being located axially outward of the stator teeth.

10. The stator according to claim 9, wherein the second circumferential conductor is located on a side of the first circumferential conductor away from the stator core in an axial direction of the stator core.

11. The stator according to any one of claims 1 to 10, wherein the stator winding includes a multi-phase winding including a plurality of first coil groups and a plurality of second coil groups, the first coil groups and the second coil groups corresponding to the same phase being alternately arranged in a circumferential direction of the stator core, the first coil groups including a plurality of the first coils arranged concentrically, the second coil groups including a plurality of the second coils arranged concentrically,

Each phase winding comprises a plurality of branches connected in parallel, and each branch is connected in series with a plurality of the first coils of the first coil group and/or connected in series with a plurality of the second coils of the second coil group.

12. The stator of any one of claims 1 to 10 wherein a plurality of said conductors located within the same stator slot are connected in series.

13. The stator according to any one of claims 1-10, wherein the first coil and the second coil are preformed coils.

14. An electric machine comprising a stator according to any one of claims 1-13.

15. A vehicle comprising the electric machine according to claim 14.