CN218920099U - Stator, flat wire motor, power assembly and vehicle - Google Patents

Abstract

The application discloses a stator, a flat wire motor, a power assembly and a vehicle. The stator includes: the stator core is provided with z stator slots; each phase winding in the stator winding comprises a plurality of parallel branches, and each parallel branch comprises a plurality of hairpin coils connected with each other; the span of the first hairpin coil is y, and two support legs of the first hairpin coil are respectively positioned on the 2t-1 slot layer and the 2t slot layer; the span of the second hairpin coil is y-1, and two support legs of the second hairpin coil are respectively positioned on the 2t slot layer and the 2t+1 slot layer; the span of the third hairpin coil is y+1, and two support legs of the third hairpin coil are respectively positioned on the 2t slot layer and the 2t+1 slot layer; the span of the fourth hairpin coil is y-1, and two support legs of the fourth hairpin coil are both positioned on the nth slot layer; the span of the fifth hairpin coil is y+1, and two supporting legs of the fifth hairpin coil are both positioned on the nth slot layer. Through the mode, the stator provided by the application can realize winding wiring of the stator in the flat wire motor by less types of hairpin coils, and is beneficial to reducing manufacturing cost.

Description

Stator, flat wire motor, power assembly and vehicle

The present application claims 202210803290.8 from month 07 of 2022 and claims priority from a prior patent application entitled "stator assembly, electric machine, and vehicle", which is incorporated herein by reference in its entirety.

Technical Field

The application relates to the technical field of flat wire motors, in particular to a stator, a flat wire motor, a power assembly and a vehicle.

Background

With the vigorous development of new energy electric vehicles, the requirements on the performance of the driving motor serving as a power supply unit of the new energy electric vehicles are also becoming severe. From the technical development of the motor, the trend of high power density and miniaturization of the motor makes the motor adopting the flat wire winding a necessary choice. Compared with the traditional round wire winding motor, the flat wire winding motor benefits from high copper fullness, can facilitate heat dissipation of the motor winding, can improve the voltage withstand capability of the winding and reduce the length of the winding end, and has the advantages of low loss, high efficiency, high power density, good heat dissipation performance, low noise and the like.

However, the following technical problems are: the flat wire design flexibility is poor, and the improper design of the arrangement of the flat wire coils in the stator slots and the connection mode of the winding inlet and outlet wires can lead to various flat wire coils, so that the production and assembly are difficult and the tooling die cost is increased.

Disclosure of Invention

The application mainly provides a stator, a flat wire motor, a power assembly and a vehicle to solve the problem that the production process is complicated and the manufacturing cost is high due to the fact that the line type of a hairpin coil is multiple in the flat wire motor.

In order to solve the technical problems, one technical scheme adopted by the application is as follows: a stator of a flat wire motor is provided. The stator includes: the stator comprises a stator core, wherein z stator slots are uniformly distributed on the inner wall of the stator core along the circumferential direction of the stator core; the stator winding comprises three-phase windings which are sequentially arranged in a periodic manner along the circumferential direction of the stator core, each phase winding comprises a plurality of parallel branches, the parallel branches are rotationally symmetrical in the circumferential direction, each parallel branch comprises a plurality of hairpin coils connected by connecting wires, n layers of flat wire conductors of the hairpin coils are arranged in each stator slot, and n is an odd number; the hairpin coil comprises a first hairpin coil, a second hairpin coil, a third hairpin coil, a fourth hairpin coil and a fifth hairpin coil, wherein the fourth hairpin coil and the fifth hairpin coil are positioned on different parallel branches in an in-phase winding; the first supporting leg and the second supporting leg of the first hairpin coil are respectively positioned on a 2t-1 slot layer and a 2t slot layer, wherein y=z/2p, p is the counter-pole number of the flat wire motor, and t is less than or equal to (n-1)/2; the span of the second hairpin coil is y-1 stator slots, and the first support leg and the second support leg of the second hairpin coil are respectively positioned on the 2t slot layer and the 2t+1 slot layer; the span of the third hairpin coil is y+1 stator slots, and the first support leg and the second support leg of the third hairpin coil are respectively positioned on the 2t slot layer and the 2t+1 slot layer; the span of the fourth hairpin coil is y-1 stator slots, and the first support leg and the second support leg of the fourth hairpin coil are both positioned on the nth slot layer; the span of the fifth hairpin coil is y+1 stator slots, and the first support leg and the second support leg of the fifth hairpin coil are both positioned on the nth slot layer.

In some embodiments, 2p-2 first hairpin coils distributed in the same slot layer number are welded and connected by welding ends of the first hairpin coils, wherein every two first hairpin coils distributed in the same slot layer number are welded and connected after every other first hairpin coil.

In some embodiments, each phase winding includes two parallel branches.

In some embodiments, the hairpin of each of the parallel legs traverses n slot layers in different stator slots.

In some embodiments, the hairpin coil includes a first leg, a second leg, a connecting section, a first bending section and a second bending section, where the first leg and the second leg are arranged in parallel and are respectively inserted into groove layers of different stator grooves, the connecting section is connected to one end of the first leg and one end of the second leg, the first bending section is connected to the other end of the first leg, the second bending section is connected to the other end of the second leg, and the first bending section and the second bending section are both connected with welding ends.

In some embodiments, the bending directions of the first bending section and the second bending section are parallel or symmetrically arranged.

In some embodiments, all of the outgoing lines and neutral points of the three-phase winding are centrally distributed in a first slot layer of different stator slots.

In order to solve the technical problems, another technical scheme adopted by the application is as follows: a flat wire motor is provided. The flat wire motor comprises a rotor and the stator, wherein the rotor is arranged in a space formed by the inner wall of the stator core in a surrounding mode.

In order to solve the technical problems, another technical scheme adopted by the application is as follows: a powertrain is provided. The power assembly comprises a speed reducer and the flat wire motor, and the flat wire motor is in transmission connection with the speed reducer.

In order to solve the technical problems, another technical scheme adopted by the application is as follows: a vehicle is provided. The vehicle comprises a powertrain as described above.

The beneficial effects of this application are: unlike the prior art, the present application discloses a stator, a flat wire motor, a powertrain and a vehicle. The number of the slot layers of the stator slots in the stator core is an odd number, and the types of the hairpin coils in each phase of winding are limited, so that the winding wiring of the stator in the flat wire motor can be realized by fewer types of hairpin coils, the design mode of the winding of the flat wire motor is widened, the manufacturing die of the stator in the flat wire motor is reduced, the manufacturing cost is reduced, the manufacturing process is simplified, the processing and manufacturing efficiency is effectively improved, circulation can be avoided when the flat wire motor normally operates, the copper loss of the motor is reduced, and the motor efficiency is improved.

Drawings

For a clearer description of embodiments of the present application or of the solutions of the prior art, the drawings that are required to be used in the description of the embodiments or of the prior art will be briefly described, it being apparent that the drawings in the description below are only some embodiments of the present application, and that other drawings may be obtained, without inventive effort, by a person skilled in the art from these drawings, in which:

fig. 1 is a schematic structural view of an embodiment of a stator of a flat wire motor provided herein;

fig. 2 is a schematic structural view of a stator core in the stator shown in fig. 1;

FIG. 3 is a schematic view of a structure of a hairpin in the stator of FIG. 1;

FIG. 4 is a schematic view of another construction of the hairpin coil of the stator of FIG. 1;

FIG. 5 is a schematic winding diagram of a U-phase winding provided in the present application with a number of slots of 48 and a number of slots of 7;

fig. 6 is a schematic diagram of the connection of two parallel branches of the U-phase winding in the embodiment of fig. 5.

Detailed Description

The following description of the technical solutions in the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

The terms "first," "second," "third," and the like in the embodiments of the present application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", and "a third" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise. Furthermore, the terms "comprise" and "have," as well as any variations thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those listed steps or elements but may include other steps or elements not listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

For ease of understanding, the terms appearing in the present application are explained below.

And (3) a stator: refers to a stationary part of the motor that functions to generate a rotating magnetic field.

A rotor: refers to a rotating component in the motor, and is used for realizing the conversion of electric energy and mechanical energy.

Span: refers to the distance spanned by two element edges of the same element in the motor winding on the surface of the armature, and is generally expressed by the number of stator slots formed in the stator core.

Referring to fig. 1 and 2, fig. 1 is a schematic structural view of an embodiment of a stator of a flat wire motor provided in the present application, and fig. 2 is a schematic structural view of a stator core in the stator shown in fig. 1.

The embodiment of the application provides a flat wire motor, this flat wire motor includes rotor and stator, in the space that the stator core inner wall of this stator encloses and establishes the formation is located to the rotor, the counter pole number of rotor is p, the pole number of rotor is 2p, the stator includes m looks winding, every looks slot number q=z/(2 pm), q can be 2 etc. of this flat wire motor, the slot pole cooperation of this flat wire motor can be 6 utmost point 54 slots or 8 utmost point 72 slots etc. this application does not make specific limitation.

As shown in fig. 1, the stator of the flat wire motor includes a stator core 10 and a stator winding 20.

As shown in fig. 2, the inner wall of the stator core 10 is provided with a plurality of stator slots 11 uniformly distributed along the circumferential direction thereof, the number of the stator slots 11 is a multiple of 3, for example, the number of the stator slots 11 may be 48, 54 or 72, any one of the stator slots 11 extends in the axial direction of the stator core 10 and penetrates through the inner wall of the stator core 10 along the axial direction of the stator core 10, the stator slots 11 are further divided into n layers along the radial direction of the stator core 10, and each slot layer of the stator slots 11 is provided with a flat wire conductor.

The stator winding 20 includes three-phase windings, which are U-phase windings, V-phase windings, and W-phase windings, respectively, which are sequentially arranged in a periodic manner in the circumferential direction of the stator core 10. Each phase winding comprises a plurality of parallel branches, and the parallel branches are rotationally symmetrical in the circumferential direction; for example, each phase winding includes two parallel branches that are rotationally symmetrical in the circumferential direction of the stator core 10.

By limiting the rotation symmetry of a plurality of parallel branches in each winding in the circumferential direction, the magnetic fields of a plurality of parallel branches in each phase winding are distributed identically and have balanced potential, thus avoiding the circulation generated between the parallel branches, greatly reducing the additional alternating current copper loss under high frequency, improving the efficiency of the flat wire motor in high-speed operation, avoiding the local overtemperature of the winding and prolonging the service life of the flat wire motor.

In this embodiment, the stator is composed of three-phase windings and a stator core 10, the phases of which differ by 120 degrees in electrical angle, the stator winding 20 is structured in the stator core 10, each phase winding includes 2 parallel branches, and the 2 parallel branches are rotationally symmetrical in the 2 parallel branches in the in-phase winding with the central axis of the stator core 10 as the rotation axis. The central axis may also refer to the rotor centerline of the rotor in a flat wire motor when the stator is applied in a flat wire motor. The rotational symmetry may be such that one parallel branch in the in-phase winding is shifted by a certain number of stator slots and coincides with the other parallel branches in the in-phase winding.

The parallel branches in each phase winding in the stator can be connected in a star mode or a triangle mode, wherein each phase winding consists of 2 parallel branches.

Each parallel branch comprises a plurality of hairpin coils 21 connected by connecting wires, n layers of flat wire conductors of the hairpin coils 21 are arranged in each stator slot 11, and n is an odd number. The hairpin 21 is formed of a flat wire conductor having a rectangular cross section, which is inserted into the stator slot 11.

Referring to fig. 3 and 4, fig. 3 is a schematic structural view of a hairpin coil in the stator shown in fig. 1, and fig. 4 is a schematic structural view of a hairpin coil in the stator shown in fig. 1.

The hairpin coil 21 comprises a first support leg 211, a second support leg 212, a connecting section 213, a first bending section 214 and a second bending section 215, wherein the first support leg 211 and the second support leg 212 are arranged in parallel and are respectively inserted into groove layers of different stator grooves 11, the connecting section 213 is connected to one ends of the first support leg 211 and the second support leg 212, the connecting section 213 can be U-shaped or V-shaped, the first bending section 214 is connected to the other end of the first support leg 211, the second bending section 215 is connected to the other end of the second support leg 212, the first bending section 214 and the second bending section 215 are both connected with welding ends 216, and the adjacent hairpin coils in the same parallel branch are connected with the welding ends 216 through connecting wires.

Wherein the pitch of the hairpin 21 is the number of stator slots spanned by its first leg 211 and second leg 212. The first leg 211 and the second leg 212 are disposed substantially in the stator slot 11, the connecting section 213 is disposed outside the stator slot 11 and disposed on one end surface of the stator core 10, and the first bending section 214, the second bending section 215 and the welding end 216 are disposed outside the stator slot 11 and disposed on the other end surface of the stator core 10.

In one embodiment, the hairpin 21 may be inserted into the stator slot 11 and then bent to form the first bending section 214 and the second bending section 215, wherein the connection section 213 forms a wire insertion portion of the stator winding 20 and the welding end 216 forms a welding portion of the stator winding 20 after the hairpin 21 is inserted into the stator slot 11.

As shown in fig. 4, the bending directions of the first bending section 214 and the second bending section 215 of the partial hairpin coil 21 are parallel for reversing winding; as shown in fig. 3, the bending directions of the first bending section 214 and the second bending section 215 of the remaining hairpin coil 21 are symmetrically arranged for in-phase winding.

In this application, n layers of hairpin coils 21 are all provided in any stator slot 11, that is, each slot layer of the stator slot 11 is provided with a first leg 211 or a second leg 212 of a hairpin coil 21, and the hairpin coils 21 of each parallel branch traverse n slot layers in different stator slots 11, so that potential phase differences caused by positions of multiple parallel branches in the stator slots in each phase winding can be eliminated.

In an embodiment, the hairpin coils 21 in the same stator slot 11 are in phase, so that no inter-phase insulation paper is required between the first legs 211 or the second legs 212 of different layers in the same stator slot 11, and insulation cost of the flat wire motor can be reduced.

The hairpin coils 21 include a first hairpin coil, a second hairpin coil, a third hairpin coil, a fourth hairpin coil and a fifth hairpin coil, each phase winding includes the five types of hairpin coils, and the fourth hairpin coil and the fifth hairpin coil are located on different parallel branches in the in-phase winding.

In this embodiment, each phase winding includes 2 parallel branches, and then a first parallel branch of the in-phase winding may include a first hairpin coil, a second hairpin coil, a third hairpin coil, and a fifth hairpin coil, and a second parallel branch of the in-phase winding may include a first hairpin coil, a second hairpin coil, a third hairpin coil, and a fourth hairpin coil.

The span of the first hairpin coil is y stator slots, the first support leg 211 and the second support leg 212 of the first hairpin coil are respectively positioned on a 2t-1 slot layer and a 2t slot layer, wherein y=z/2p, p is the number of pairs of poles of the flat wire motor, t is less than or equal to (n-1)/2, and y and t are positive integers; the number of the first hairpin coils distributed on the same slot layer is 2p-2, and every two first hairpin coils distributed on the same slot layer are welded and connected through the welding ends of the first hairpin coils.

The span of the second hairpin coil is y-1 stator slots, and the first support leg and the second support leg of the second hairpin coil are respectively positioned on the 2t slot layer and the 2t+1 slot layer; the span of the third hairpin coil is y+1 stator slots, and the first support leg and the second support leg of the third hairpin coil are respectively positioned on the 2t slot layer and the 2t+1 slot layer; the span of the fourth hairpin coil is y-1 stator slots, and two straight line segments of the fourth hairpin coil are both positioned on the nth slot layer; the span of the fifth hairpin coil is y+1 stator slots, and two straight line sections of the fifth hairpin coil are both positioned on the nth slot layer.

For example, the first hairpin coil has a span of 6 stator slots 11, the second hairpin coil has a span of 5 stator slots 11, the third hairpin coil has a span of 7 stator slots 11, the fourth hairpin coil has a span of 5 stator slots 11, and the fifth hairpin coil has a span of 7 stator slots 11.

The multiple parallel branches of the same phase traverse n slot layers in different stator slots, and the stator slots 11 occupied by the windings of each phase are rotationally symmetrical on the circumference of the stator, in this embodiment, the number of the rotating slots of the windings of each phase is 6, so that the two branches of the same phase are completely symmetrical, no circulation occurs during normal operation of the flat wire motor, the copper loss of the motor is reduced, and the motor efficiency is improved.

All outgoing lines and neutral points of the three-phase winding are distributed on the first slot layers of different stator slots 11 in a concentrated mode, and the outgoing lines and the neutral points of parallel branches are concentrated, so that the space of the winding in the axial direction and the radial direction can be reduced, and the manufacturing difficulty of the flat wire motor is reduced.

For example, the number of stator slots 11 in the stator core 10 is 48, and the number of slot layers n in each stator slot 11 is 7. The stator winding component is U-phase, V-phase and W-phase, and the number of parallel branches arranged on each phase winding is 2.

Referring to fig. 5 and 6, fig. 5 is a winding schematic diagram of a U-phase winding provided in the present application when the number of slots of the stator is 48 and the number of slots is 7, and fig. 6 is a connection schematic diagram of two parallel branches of the U-phase winding in the embodiment of fig. 5. Wherein, the solid line represents the connection mode of the plug terminal, the broken line represents the connection mode of the welding terminal, U1 and U2 can be used as voltage outgoing lines and neutral point outgoing lines, and X1 and X2 can be used as voltage outgoing lines and neutral point outgoing lines.

The following describes the first parallel branch, the second parallel branch and the third parallel branch in the U-phase winding in the present embodiment in detail with reference to fig. 5 and 6.

Where the number i (j) represents the j-th groove layer in the i-th groove, for example, 1 (1) represents the 1 st groove layer of the 1 st groove, and 7 (2) represents the 2 nd groove layer of the 7 th groove.

As shown in fig. 5, the first parallel leg of the U-phase winding has the following slot number through which the series connection passes: 1 (1) to 7 (2) to 13 (1) to 19 (2) to 25 (1) to 31 (2) to 37 (1) to 43 (2) to 2 (3) to 8 (4) to 14 (3) to 20 (4) to 26 (3) to 32 (4) to 38 (3) to 44 (4) to 1 (5) to 7 (6) to 13 (5) to 19 (6) to 25 (5) to 31 (6) to 37 (5) to 43 (6) to 2 (7) to 7 (7) to 14 (7) 19 (7) 26 (7) 31 (7) 38 (7) 43 (7) 38 (6) 32 (5) 26 (6) 20 (5) 14 (6) 8 (5) 1 (4) 43 (3) 37 (4) 31 (3) 25 (4) 19 (3) 13 (4) 7 (3) 2 (2) 44 (1) 38 (2) 32 (1) 26 (2) 20 (1) 14 (2) 8 (1).

Wherein, the numbers 44 (4) to 1 (5), 7 (3) to 2 (2), 43 (7) to 38 (6) are second hairpin coils, and the bending directions of the first bending section 214 and the second bending section 215 of the hairpin coils from 43 (7) to 38 (6) are parallel, and the parallel branch circuit starts reversing winding through the hairpin coils.

The third hairpin is designated by the numbers 43 (2) to 2 (3), 43 (6) to 2 (7), 8 (5) to 1 (4).

The fifth hairpin is numbered 7 (7) to 14 (7), 19 (7) to 26 (7), 31 (7) to 38 (7).

The rest hairpin coils in the parallel branch are all first hairpin coils.

1 (1) is the number of the outgoing line of the first parallel branch in the U-phase winding, and 8 (1) is the number of the neutral point of the first parallel branch in the U-phase winding.

As shown in fig. 5, the second parallel branch of the U-phase winding has the following slot number through which the series connection passes: 2 (1) to 8 (2) to 14 (1) to 20 (2) to 26 (1) to 32 (2) to 38 (1) to 44 (2) to 1 (3) to 7 (4) to 13 (3) to 19 (4) to 25 (3) to 31 (4) to 37 (3) to 43 (4) to 2 (5) to 8 (6) to 14 (5) to 20 (6) to 26 (5) to 32 (6) to 38 (5) to 44 (6) to 1 (7) to 8 (7) to 13 (7) to 20 (7) to 25 (7) to 32 (7) to 37 (7) to 44 (7) to 37 (6) to 31 (5) to 25 (6) to 19 (5) to 13 (6) to 7) to 4 (5) to 2 (4) to 14 (5) to 38) to 1 (7) to 12 (7) to 3 (4) to 3 (7) to 3).

Wherein, the numbers 44 (2) to 1 (3), 44 (6) to 1 (7), 7 (5) to 2 (4) are the second hairpin.

The third hairpin coil is designated by the numbers 43 (4) to 2 (5), 8 (3) to 1 (2), 44 (7) to 37 (6), and the bending directions of the first bending section 214 and the second bending section 215 of the hairpin coil from the numbers 44 (7) to 37 (6) are parallel, and the parallel branch starts reversing winding through the hairpin coil.

The fourth hairpin is numbered 8 (7) to 13 (7), 20 (7) to 25 (7), and 32 (7) to 37 (7).

The remaining hairpin coils 21 in the parallel branch are all first hairpin coils.

2 (1) is the number of the outgoing line of the second parallel branch in the U-phase winding, and 7 (1) is the number of the neutral point of the second parallel branch in the U-phase winding.

The U-phase winding, the V-phase winding and the W-phase winding are symmetrically and uniformly distributed on the circumference of the stator core 10, and in this embodiment, the V-phase winding and the W-phase winding can be obtained by rotating 2 or 4 stator slots 11 along the circumferential direction of the stator core 10 by the U-phase winding, so that the winding modes of the V-phase winding and the W-phase winding are not repeated.

The embodiment of the application also provides a power assembly, which comprises a speed reducer and the flat wire motor. Wherein, flat wire motor and reduction gear transmission are connected. Specifically, the driving shaft of the flat wire motor and the input shaft of the speed reducer can be in transmission connection through a transmission member such as a coupler, so that driving force is output from the flat wire motor to the speed reducer.

The vehicle provided by the embodiment of the application comprises the power assembly, wherein the power assembly is arranged in the vehicle and provides running power for the vehicle. Specifically, in the present embodiment, the vehicle may be specifically a new energy vehicle driven with electric energy. The new energy vehicle can be a hybrid electric vehicle, a pure electric vehicle, a fuel cell electric vehicle or the like, or can be a vehicle adopting a super capacitor, a flywheel battery or a flywheel energy accumulator or other high-efficiency energy accumulator as an electric energy source.

Unlike the prior art, the present application discloses a stator, a flat wire motor, a powertrain and a vehicle. The number of the slot layers of the stator slots in the stator core is an odd number, and the types of the hairpin coils in each phase of winding are limited, so that the winding wiring of the stator in the flat wire motor can be realized by fewer types of hairpin coils, the design mode of the winding of the flat wire motor is widened, the manufacturing die of the stator in the flat wire motor is reduced, the manufacturing cost is reduced, the manufacturing process is simplified, the processing and manufacturing efficiency is effectively improved, circulation can be avoided when the flat wire motor normally operates, the copper loss of the motor is reduced, and the motor efficiency is improved.

The foregoing description is only exemplary embodiments of the present application and is not intended to limit the scope of the present application, and all equivalent structures or equivalent processes using the descriptions and the drawings of the present application, or direct or indirect application in other related technical fields are included in the scope of the present application.

Claims (10)

1. A stator of a flat wire motor, comprising:

the stator comprises a stator core, wherein z stator slots are uniformly distributed on the inner wall of the stator core along the circumferential direction of the stator core;

the stator winding comprises three-phase windings which are sequentially arranged in a periodic manner along the circumferential direction of the stator core, each phase winding comprises a plurality of parallel branches, the parallel branches are rotationally symmetrical in the circumferential direction, each parallel branch comprises a plurality of hairpin coils connected by connecting wires, n layers of flat wire conductors of the hairpin coils are arranged in each stator slot, and n is an odd number;

the hairpin coil comprises a first hairpin coil, a second hairpin coil, a third hairpin coil, a fourth hairpin coil and a fifth hairpin coil, wherein the fourth hairpin coil and the fifth hairpin coil are positioned on different parallel branches in an in-phase winding;

the first supporting leg and the second supporting leg of the first hairpin coil are respectively positioned on a 2t-1 slot layer and a 2t slot layer, wherein y=z/2p, p is the counter-pole number of the flat wire motor, and t is less than or equal to (n-1)/2; the span of the second hairpin coil is y-1, and the first support leg and the second support leg of the second hairpin coil are respectively positioned on the 2t slot layer and the 2t+1 slot layer; the span of the third hairpin coil is y+1, and the first support leg and the second support leg of the third hairpin coil are respectively positioned on the 2t slot layer and the 2t+1 slot layer; the span of the fourth hairpin coil is y-1, and the first support leg and the second support leg of the fourth hairpin coil are both positioned on the nth slot layer; the span of the fifth hairpin coil is y+1, and the first support leg and the second support leg of the fifth hairpin coil are both positioned on the nth groove layer.

2. The stator of claim 1, wherein 2p-2 of said first hairpin coils are distributed in the same slot layer number, and every second of said first hairpin coils is welded by welding ends of said first hairpin coils.

3. The stator of claim 1, wherein each phase winding comprises two parallel branches.

4. The stator of claim 1 wherein each of said parallel-branched hairpin traverses n slot layers in a different stator slot.

5. The stator of claim 1, wherein the hairpin includes a first leg, a second leg, a connecting section, a first bending section, and a second bending section, the first leg and the second leg are disposed in parallel and are respectively inserted into slot layers of different stator slots, the connecting section is connected to one ends of the first leg and the second leg, the first bending section is connected to the other end of the first leg, the second bending section is connected to the other end of the second leg, and the first bending section and the second bending section are both connected with welding ends.

6. The stator of claim 5, wherein the bending directions of the first bending section and the second bending section are parallel or symmetrically arranged.

7. The stator of claim 5, wherein all of the outgoing and neutral points of the three-phase winding are centrally distributed in a first slot layer of different stator slots.

8. A flat wire motor comprising a rotor and a stator according to any one of claims 1 to 7, wherein the rotor is provided in a space defined by an inner wall of the stator core.

9. A powertrain comprising a speed reducer and the flat wire motor of claim 8, wherein the flat wire motor is drivingly connected to the speed reducer.

10. A vehicle comprising the powertrain of claim 9.

Images