Flat wire motor, power assembly, and electric vehicle

Abstract

The present application provides a flat wire motor, a power assembly, and an electric vehicle. A motor stator of the flat wire motor comprises a plurality of winding slots and N turns of flat wires arranged in the radial direction of the flat wire motor, N is an integer greater than or equal to 2, each turn of flat wires comprises a plurality of pairs of flat wires arranged in the circumferential direction of the flat wire motor, each winding slot is used for accommodating one pair of flat wires in each turn of flat wires, and each pair of flat wires comprises an outer-layer flat wire and an inner-layer flat wire. The N turns of flat wires comprise a first turn of flat wires, the outer-layer flat wires in the first turn of flat wires comprise a first flat wire, a second flat wire, and a third flat wire, and the first flat wire, the second flat wire, and the third flat wire are connected to corresponding inner-layer flat wires respectively by means of three crossover segments having different lengths. The first flat wire, the second flat wire, and the third flat wire are connected to the corresponding inner-layer flat wires respectively by means of three crossover segments having different lengths, thereby implementing a winding having a consecutive short-pitch configuration, and improving the NVH performance of the flat wire motor.

Description

Flat wire motor, power assembly and electric vehicle

[0001] The present application claims priority to the Chinese patent application No. 202411264556.1, filed on September 9, 2024, entitled "Flat wire motor, power assembly and electric vehicle", the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0002] The present application relates to the technical field of flat wire motors, in particular to a flat wire motor, a power assembly and an electric vehicle. BACKGROUND

[0003] At present, the driving motor of new energy vehicles mainly adopts permanent magnet synchronous motor. In the permanent magnet synchronous motor, the cross-sectional shape of the stator winding in the motor stator can be divided into circular wire conductors and flat copper wire conductors. The motor using flat copper wire conductors is called flat wire motor. The short-pitch winding of three-phase balance is difficult to realize due to the influence of automatic wire-off process in traditional circular wire motor, while the flat wire motor can effectively improve the slot fill rate, improve the power density and torque density. With the rapid development of the new energy vehicle industry, the requirements for the number of layers, the number of parallel branches and the winding form of the flat wire motor are becoming higher and higher. At present, the existing winding method of the stator winding of the flat wire motor is mainly full-pitch winding. The flat wire motor with full-pitch structure has a high harmonic winding coefficient, and the torque fluctuation is large during operation, which deteriorates the noise, vibration and roughness of the motor, and reduces the performance of the motor. By setting the stator winding as a short-pitch winding to reduce the harmonic winding coefficient of the flat wire motor, the NVH performance of the electric vehicle is improved. However, the existing flat wire short-pitch winding with balanced multi-branch has a complex structure, which makes the winding processing difficult and the winding difficult. Moreover, the short-pitch setting method is limited by the winding form, it is difficult to effectively weaken the harmonic winding coefficient while obtaining a high fundamental winding coefficient, which reduces the performance of the flat wire motor. SUMMARY

[0004] The present application provides a flat wire motor, a power assembly and an electric vehicle.

[0005] In a first aspect, the application provides a flat wire motor, a motor stator of the flat wire motor comprising a plurality of winding slots and N layers of flat wires, the N layers of flat wires being arranged along a radial direction of the flat wire motor, N being an integer greater than or equal to 2, each layer of flat wires comprising a plurality of pairs of flat wires arranged along a circumferential direction of the flat wire motor, each winding slot being configured to accommodate one pair of flat wires in each layer of the N layers of flat wires, each pair of flat wires comprising an outer layer flat wire and an inner layer flat wire, a distance between one outer layer flat wire and an axis of the flat wire motor along the radial direction being greater than a distance between one inner layer flat wire and the axis of the flat wire motor, and one outer layer flat wire in each pair of flat wires in each layer of flat wires being configured to be connected to one inner layer flat wire in another pair of flat wires. In the N layers of flat wires, a first layer of flat wires comprises first, second and third flat wires as outer layer flat wires, and the first, second and third flat wires are connected to corresponding inner layer flat wires by three cross wire segments with different lengths, respectively.

[0006] In the embodiments of the application, the N layers of flat wires are arranged along a radial direction of the flat wire motor, N being an integer greater than or equal to 2, each layer of flat wires comprising a plurality of pairs of flat wires, the plurality of pairs of flat wires in each layer of flat wires being arranged along a circumferential direction of the flat wire motor, so that the outer layer flat wire and the inner layer flat wire in the adjacent two layers in each layer of flat wires can be connected in series, thereby facilitating the winding to be connected in series in multiple layers, reducing the flat wire eddy current loss, improving the efficiency of the flat wire motor at high speed, and increasing the diversity of the number of turns of the winding connected in series and improving the performance of the flat wire motor.

[0007] In the embodiments of the application, the distance between one outer layer flat wire and an axis of the flat wire motor along the radial direction is greater than the distance between one inner layer flat wire and the axis of the flat wire motor, so that the outer layer flat wires in the first layer of flat wires are located at the bottom layer of the winding slots.

[0008] In the embodiments of the application, the first, second and third flat wires in the first layer of flat wires are connected to corresponding inner layer flat wires by three cross wire segments with different lengths, respectively, so that the winding mode of the first layer of flat wires in the winding slots has multiple spans, which facilitates the winding to be connected in series in a continuous short distance in the motor stator of the N layers of flat wires, thereby weakening the harmonic magnetic field of the flat wire motor and improving the NVH performance of the flat wire motor.

[0009] In one embodiment, the difference between the number of slots crossed by one cross wire segment connected to the third flat wire and the number of slots crossed by one cross wire segment connected to the second flat wire is 1, and the difference between the number of slots crossed by one cross wire segment connected to the second flat wire and the number of slots crossed by one cross wire segment connected to the first flat wire is 2.

[0010] In the embodiment of the present application, the slot numbers of the slots crossed by the one crossover segment of the first flat wire, the one crossover segment of the second flat wire and the one crossover segment of the third flat wire are all different, so that the winding mode of the flat wire in the slot has multiple spans, which is beneficial to realize the effect of continuous short span of the winding, thereby weakening the harmonic magnetic field of the flat wire motor and improving the NVH performance of the flat wire motor.

[0011] In one embodiment, the first flat wire and the one inner layer flat wire connected thereto are arranged between the third flat wire and the one inner layer flat wire connected thereto.

[0012] In the embodiment of the present application, the first flat wire and the one inner layer flat wire connected thereto are arranged between the third flat wire and the one inner layer flat wire connected thereto, so that the slot number of the slot crossed by the crossover segment connecting the first flat wire and the one inner layer flat wire connected thereto is smaller than the slot number of the slot crossed by the crossover segment connecting the third flat wire and the one inner layer flat wire connected thereto, which is beneficial to form a short span winding, thereby reducing the harmonic winding coefficient and improving the NVH performance of the flat wire motor.

[0013] In one embodiment, one first flat wire and one third flat wire are arranged adjacent to each other, and the one inner layer flat wire connected to the first flat wire and the one inner layer flat wire connected to the third flat wire are spaced apart by one slot.

[0014] In the embodiment of the present application, one first flat wire and one third flat wire are arranged adjacent to each other, and the one inner layer flat wire connected to the first flat wire and the one inner layer flat wire connected to the third flat wire are spaced apart by one slot, so that the slot number of the slot crossed by the crossover segment connecting the first flat wire and the inner layer flat wire connected thereto is different from the slot number of the slot crossed by the crossover segment connecting the third flat wire and the inner layer flat wire connected thereto, which is beneficial to form a short span winding, thereby reducing the harmonic winding coefficient and improving the NVH performance of the flat wire motor.

[0015] In one embodiment, the outer layer flat wires in the first circle of flat wires include two third flat wires, and the two third flat wires are arranged adjacent to each other on the same side of the first flat wire along the circumferential direction of the flat wire motor.

[0016] In the embodiment of the present application, the two third flat wires are arranged adjacent to each other on the same side of the first flat wire along the circumferential direction of the flat wire motor, so that the slot numbers of the two slots crossed by the two crossover segments respectively connecting the two third flat wires and the inner layer flat wires connected thereto are the same, so that the winding arrangement is regular, and the wire insertion process of the winding can also be simplified.

[0017] In one embodiment, the one inner layer flat wire connected to one first flat wire or one third flat wire and one second flat wire are arranged adjacent to each other in one slot along the radial direction of the flat wire motor.

[0018] In the embodiment of the present application, the inner layer flat wire connected with the first flat wire or the third flat wire and the second flat wire are arranged in the same winding slot in the radial direction of the flat wire motor, which is beneficial to make each circle of flat wire traverse in the winding slot, so as to keep the potential balance and avoid the generation of circulating current.

[0019] In an embodiment, the outer layer flat wire in the first circle of flat wires comprises a plurality of second flat wires, the plurality of second flat wires are arranged in sequence in the circumferential direction of the flat wire motor, and the plurality of second flat wires and the inner layer flat wire connected therewith are connected through the same cross-over segment.

[0020] In the embodiment of the present application, the plurality of second flat wires are arranged in sequence in the circumferential direction of the flat wire motor, and the plurality of second flat wires and the inner layer flat wire connected therewith are connected through the same cross-over segment, so that the winding wire arrangement is regular, and the winding insertion process can be simplified.

[0021] In an embodiment, the N circles of flat wires further comprise a second circle of flat wires, the second circle of flat wires is arranged in the radial direction of the flat wire motor with the first circle of flat wires, the distance between the outer layer flat wire in the first circle of flat wires and the axis of the flat wire motor is greater than the distance between the outer layer flat wire in the second circle of flat wires and the axis of the flat wire motor, and an inner layer flat wire in the first circle of flat wires is used to fixedly connect an outer layer flat wire in the second circle of flat wires through a cross-over segment.

[0022] In the embodiment of the present application, the distance between the outer layer flat wire in the first circle of flat wires and the axis of the flat wire motor is greater than the distance between the outer layer flat wire in the second circle of flat wires and the axis of the flat wire motor, that is, the first circle of flat wires is a circle of flat wires close to the bottom of the winding slot.

[0023] In the embodiment of the present application, the inner layer flat wire in the first circle of flat wires is used to fixedly connect the outer layer flat wire in the second circle of flat wires through the cross-over segment, so as to realize the series connection of the first circle of flat wires and the second circle of flat wires, which is beneficial to realize the multi-layer series connection of the winding, reduce the flat wire eddy current loss, improve the efficiency of the flat wire motor at high speed, increase the diversity of the winding series turns, and improve the performance of the flat wire motor.

[0024] In an embodiment, the length of the cross-over segment between the inner layer flat wire in the first circle of flat wires and the outer layer flat wire in the second circle of flat wires connected therewith is less than or equal to the length of the cross-over segment between the third flat wire in the first circle of flat wires and the inner layer flat wire connected therewith.

[0025] In the embodiment of the present application, the length of the cross-line segment between the inner layer flat wire of the first circle of flat wires and the outer layer flat wire of the second circle of flat wires connected thereto is less than the length of the cross-line segment between the third flat wire of the first circle of flat wires and the inner layer flat wire connected thereto, which is conducive to forming a short-circuit winding, enabling the winding to achieve a continuous short-distance effect, thereby weakening the harmonic magnetic field of the flat wire motor and improving the NVH performance of the flat wire motor.

[0026] In the embodiment of the present application, the length of the cross-line segment between the inner layer flat wire of the first circle of flat wires and the outer layer flat wire of the second circle of flat wires connected thereto is equal to the length of the cross-line segment between the third flat wire of the first circle of flat wires and the inner layer flat wire connected thereto, which is conducive to reducing the types of cross-line segment lengths and simplifying the winding process.

[0027] In an embodiment, the difference between the number of slots of the winding slot crossed by the cross-line segment between the third flat wire of the first circle of flat wires and the inner layer flat wire connected thereto and the number of slots of the winding slot crossed by the cross-line segment between the inner layer flat wire of the first circle of flat wires and the outer layer flat wire of the second circle of flat wires connected thereto is 1 or 2 or 3.

[0028] In the embodiment of the present application, the difference between the number of slots of the winding slot crossed by the cross-line segment between the third flat wire of the first circle of flat wires and the inner layer flat wire connected thereto and the number of slots of the winding slot crossed by the cross-line segment between the inner layer flat wire of the first circle of flat wires and the outer layer flat wire of the second circle of flat wires connected thereto is 1 or 2 or 3, which enables the connection of the flat wires in the winding to have a more diverse connection mode and provides more winding routing schemes. It is also conducive to increasing the diversity of series turns of the winding and improving the performance of the flat wire motor.

[0029] In an embodiment, the outer layer flat wires in the second circle of flat wires include a first flat wire, a second flat wire and a third flat wire, and the number of slots of the winding slot crossed by the cross-line segment between the first flat wire in the first circle of flat wires and the inner layer flat wire connected thereto is equal to the number of slots of the winding slot crossed by the cross-line segment between the first flat wire in the second circle of flat wires and the inner layer flat wire connected thereto.

[0030] In the embodiment of the present application, the number of slots of the winding slot crossed by the cross-line segment between the first flat wire in the first circle of flat wires and the inner layer flat wire connected thereto is equal to the number of slots of the winding slot crossed by the cross-line segment between the first flat wire in the second circle of flat wires and the inner layer flat wire connected thereto, which is conducive to enabling the two circles of flat wires in the winding slot to have the same cross-line connection mode, thereby facilitating the winding routing to be more regular and have a better appearance, and also simplifying the winding process and facilitating automatic winding.

[0031] In an embodiment, the outer flat wire in the second circle of flat wires includes the first flat wire, the second flat wire and the third flat wire, and the difference between the slot number of the winding slot crossed by the cross wire segment between the first flat wire and the inner flat wire connected thereto in the first circle of flat wires and the slot number of the winding slot crossed by the cross wire segment between the first flat wire and the inner flat wire connected thereto in the second circle of flat wires is 1.

[0032] In the embodiment, the difference between the slot number of the winding slot crossed by the cross wire segment between the first flat wire and the inner flat wire connected thereto in the first circle of flat wires and the slot number of the winding slot crossed by the cross wire segment between the first flat wire and the inner flat wire connected thereto in the second circle of flat wires is 1, which is conducive to making the second circle of flat wires and the first flat wire and the inner flat wire connected thereto in the first circle of flat wires have different cross distances in the winding slot, thereby facilitating the formation of a short-pitch winding and the realization of continuous short-pitch winding in the motor stator of the multi-circle flat wire motor, thereby weakening the harmonic magnetic field of the flat wire motor and improving the NVH performance of the flat wire motor.

[0033] In an embodiment, the outer flat wire in the second circle of flat wires includes the first flat wire, the second flat wire and the third flat wire, and the difference between the slot number of the winding slot crossed by the cross wire segment between the first flat wire and the inner flat wire connected thereto in the second circle of flat wires and the slot number of the winding slot crossed by the cross wire segment between the first flat wire and the inner flat wire connected thereto in the first circle of flat wires is 1.

[0034] In the embodiment, the difference between the slot number of the winding slot crossed by the cross wire segment between the first flat wire and the inner flat wire connected thereto in the second circle of flat wires and the slot number of the winding slot crossed by the cross wire segment between the first flat wire and the inner flat wire connected thereto in the first circle of flat wires is 1, which is conducive to making the second circle of flat wires and the first flat wire and the inner flat wire connected thereto in the first circle of flat wires have different cross distances in the winding slot, thereby facilitating the formation of a short-pitch winding and the realization of continuous short-pitch winding in the motor stator of the multi-circle flat wire motor, thereby weakening the harmonic magnetic field of the flat wire motor and improving the NVH performance of the flat wire motor.

[0035] In a second aspect, the application provides a power assembly, which includes a reducer and the flat wire motor of the first aspect, the motor shaft of the flat wire motor is used for driving connection with the input shaft of the reducer, and the output shaft of the reducer is used for driving the wheels of the electric vehicle.

[0036] The first flat wire, the second flat wire and the third flat wire in the first circle of flat wires in the motor stator of the flat wire motor are respectively connected with the inner layer flat wires corresponding thereto through three cross wire segments with different lengths, so that the wire winding mode of the first circle of flat wires in the winding slot has multiple spans, which is beneficial to realize the effect of continuous short distance of the winding in the motor stator of multiple circles of flat wires, thereby weakening the harmonic magnetic field of the flat wire motor, improving the NVH performance of the flat wire motor, and further improving the NVH performance of the power assembly.

[0037] In a third aspect, the present application provides an electric vehicle, which comprises a vehicle frame, a power battery and a power assembly as the second aspect, the vehicle frame is used for fixing the power battery and the power assembly, the power battery is used for supplying power to the motor, and the motor is used for driving the wheels of the electric vehicle through the reducer.

[0038] The power assembly in the embodiment of the present application comprises a flat wire motor, the first flat wire, the second flat wire and the third flat wire in the first circle of flat wires in the motor stator of the flat wire motor are respectively connected with the inner layer flat wires corresponding thereto through three cross wire segments with different lengths, so that the wire winding mode of the first circle of flat wires in the winding slot has multiple spans, which is beneficial to realize the effect of continuous short distance of the winding in the motor stator of multiple circles of flat wires, thereby weakening the harmonic magnetic field of the flat wire motor, improving the NVH performance of the flat wire motor, and further improving the NVH performance of the power assembly and the overall performance of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the embodiments of the present application will be described below.

[0040] FIG. 1 is a structural schematic diagram of an electric vehicle provided by the embodiments of the present application;

[0041] FIG. 2 is a structural schematic diagram of a power assembly provided by the embodiments of the present application;

[0042] FIG. 3 is a top view structural schematic diagram of a flat wire inserted into a winding slot provided by the embodiments of the present application;

[0043] FIG. 4 is a structural schematic diagram of a hairpin coil provided by the embodiments of the present application;

[0044] FIG. 5 is a connection schematic diagram of two parallel branches of a U-phase winding provided by the embodiments of the present application;

[0045] FIG. 6 is a connection schematic diagram of two parallel branches of a U-phase winding provided by the embodiments of the present application;

[0046] FIG. 7 is a connection schematic diagram of two parallel branches of a U-phase winding provided by the embodiments of the present application;

[0047] Fig. 8 is a schematic diagram of connection of two parallel branches of the U-phase winding according to an embodiment of the present application;

[0048] Fig. 9 is a schematic diagram of connection of one branch of the U-phase winding according to an embodiment of the present application;

[0049] Fig. 10 is a schematic diagram of connection of two parallel branches of the U-phase winding according to an embodiment of the present application;

[0050] Fig. 11 is a schematic diagram of connection of the end of the three-phase winding according to an embodiment of the present application;

[0051] Fig. 12 is another schematic diagram of connection of the end of the three-phase winding according to an embodiment of the present application;

[0052] Fig. 13 is a schematic diagram of structure of the welded end of the stator of the motor according to an embodiment of the present application;

[0053] Fig. 14 is a schematic diagram of structure of the crown end of the stator of the motor according to an embodiment of the present application;

[0054] Fig. 15 is a comparison diagram of torque ripple of the winding peak operating point according to an embodiment of the present application. DETAILED DESCRIPTION

[0055] The technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments.

[0056] For the convenience of understanding, the English abbreviations and related technical terms involved in the embodiments of the present application will be explained and described below.

[0057] NVH: is the English abbreviation of Noise, Vibration, Harshness, that is, noise, vibration and sound roughness.

[0058] Busbar: is a kind of multi-layer composite connection row, which can be regarded as the core channel of the power distribution system. Compared with the traditional wiring method, it has the advantages of convenient design, low impedance, strong anti-interference ability, high reliability, good space utilization and rapid assembly.

[0059] Pole number: that is, the number of magnetic poles of the motor. The magnetic poles are N poles and S poles. One N pole and one S pole are generally referred to as a pair of magnetic poles, that is, the pole pair number is 1. Therefore, the pole pair number of the motor is 1, 2, 3 or 4, and the pole number of the motor is 2, 4, 6 or 8.

[0060] Pole pitch: the pole pitch of the winding refers to the distance of the surface of each magnetic pole. For an alternating current motor, it refers to the slot pitch occupied by each magnetic pole along the inner circle of the stator core. The pole pitch f is equal to the ratio of the stator slot number Z to the magnetic pole number 2p, that is, f=z / 2p.

[0061] Pitch: also called the span of the coil, refers to the number of slots between the two effective edges of a single coil, for example, pitch y = 6, that is, the two effective edges of the coil are separated by 6 slots, that is, the two effective edges are embedded in the 1st slot and the 7th slot.

[0062] Slots per pole per phase q: the number of slots occupied by each phase winding under each magnetic pole is called slots per pole per phase.

[0063] In addition, the winding mode of the stator winding includes full-pitch winding and short-pitch winding, wherein the full-pitch winding is a stator winding with a pitch equal to the pole pitch, and the short-pitch winding is a stator winding with a pitch less than the pole pitch.

[0064] In order to realize the short-pitch effect of the flat wire motor, the application provides a flat wire motor, the motor stator of the flat wire motor includes a plurality of winding slots and N coils of flat wires, the N coils of flat wires are arranged along the radial direction of the flat wire motor, N is an integer greater than or equal to 2, each coil of flat wire includes a plurality of pairs of flat wires arranged along the circumferential direction of the flat wire motor, each winding slot is used to accommodate a pair of flat wires in each coil of the N coils of flat wires, each pair of flat wires includes an outer layer flat wire and an inner layer flat wire, the distance between an outer layer flat wire and the axis of the flat wire motor along the radial direction of the flat wire motor is greater than the distance between an inner layer flat wire and the axis of the flat wire motor, and one outer layer flat wire in each pair of flat wires of each coil of flat wire is used to connect one inner layer flat wire in another pair of flat wires. Wherein, the N coils of flat wires include a first coil of flat wires, the outer layer flat wires in the first coil of flat wires include a first flat wire, a second flat wire and a third flat wire, and the first flat wire, the second flat wire and the third flat wire are connected to the inner layer flat wires corresponding to them respectively through three cross-line segments with different lengths. The first flat wire, the second flat wire and the third flat wire in the first coil of flat wires are connected to the inner layer flat wires corresponding to them respectively through three cross-line segments with different lengths, so that the winding mode of the first coil of flat wires in the winding slot has multiple spans, which is conducive to realizing the continuous short-pitch effect of the winding in the motor stator with multiple coils of flat wires, thereby weakening the harmonic magnetic field of the flat wire motor and improving the NVH performance of the flat wire motor.

[0065] FIG. 1 is a structural schematic diagram of an electric vehicle 1 provided by an embodiment of the application.

[0066] In an embodiment, the electric vehicle 1 includes a power assembly 10, a vehicle frame 20, a power battery 30 and a vehicle wheel 40. As shown in FIG. 1, the power assembly 10 and the power battery 30 are fixed to the vehicle frame 20. The power assembly 10 is used to receive power supply from the power battery 30 and drive the vehicle wheel 40. In the embodiment of the application, the power battery 30 can also be referred to as a battery pack. In the embodiment of the application, the vehicle frame 20 can also be referred to as a vehicle body. In the embodiment of the application, the electric vehicle 1 refers to a wheeled device driven or pulled by a power device.

[0067] FIG. 2 is a structural schematic diagram of the power assembly 10 provided by an embodiment of the application.

[0068] In an embodiment, the power assembly 10 comprises a flat wire motor 100 and a reducer 200, as shown in FIG. 2, the flat wire motor 100 comprises a motor shaft (not shown), a motor stator 101 and a motor rotor (not shown), the reducer 200 comprises a gear assembly (not shown), an input shaft (not shown) and an output shaft (not shown), the input shaft receives power transmitted by the motor shaft of the flat wire motor 100 and transmits the power to the output shaft through the gear assembly. The gear assembly can be arranged as required, which can be a single-gear reducer, a two-gear or multi-gear reducer. The motor rotor is fixedly sleeved on the motor shaft, and the motor stator 101 drives the motor rotor to rotate after receiving alternating current, thereby driving the motor shaft to rotate. The motor shaft of the flat wire motor 100 is used to be drivingly connected with the input shaft of the reducer 200, thereby driving the wheels 40 of the electric vehicle 1 to travel.

[0069] In the embodiment of the present application, the flat wire motor 100 and the reducer 200 are arranged along the motor shaft, and the motor shaft of the flat wire motor 100 is fixed with the input shaft of the reducer 200.

[0070] In an embodiment, the power assembly 10 further comprises a motor controller 300, which is used to convert the direct current output by the power battery 30 into alternating current and provide the alternating current to the flat wire motor 100 for power supply.

[0071] The existing flat wire short-pitch winding with balanced multi-branch in the flat wire motor has a complex structure, which makes winding processing difficult and winding difficult. The conventional short-pitch winding mode is limited by the winding form, and it is difficult to effectively weaken the harmonic winding coefficient while obtaining a higher fundamental winding coefficient, which reduces the performance of the flat wire motor. Moreover, the current short-pitch winding is usually only for the motor stator of a specific layer winding, and the application range is not wide.

[0072] The present application provides a flat wire motor with two parallel branches and a short-pitch effect, which can be applied to even layer windings, and can maximize the weakening of 6p and 12p harmonics while reducing winding alternating current loss and simplifying winding plug-in process.

[0073] The flat wire motor provided by the embodiment of the present application will be described in detail below.

[0074] Fig. 3 is a top view of the flat wire 121 inserted into the winding slot 110 according to an embodiment of the present application, Fig. 4 is a structural schematic diagram of the hairpin coil 130 according to an embodiment of the present application, Fig. 5 is a connection schematic diagram of two parallel branches of the U-phase winding according to an embodiment of the present application, Fig. 6 is a connection schematic diagram of two parallel branches of the U-phase winding according to an embodiment of the present application, Fig. 7 is a connection schematic diagram of two parallel branches of the U-phase winding according to an embodiment of the present application, Fig. 8 is a connection schematic diagram of two parallel branches of the U-phase winding according to an embodiment of the present application, Fig. 9 is a connection schematic diagram of a branch of the U-phase winding according to an embodiment of the present application, and Fig. 10 is a connection schematic diagram of two parallel branches of the U-phase winding according to an embodiment of the present application.

[0075] In an embodiment, the motor stator 101 of the flat wire motor 100 includes a stator core and a stator winding. As shown in Fig. 3, the stator core includes a plurality of winding slots 110. The number of the plurality of winding slots 110 can be a multiple of 9. In an embodiment, the number of the winding slots 110 is 54. The plurality of winding slots 110 are arranged on the inner wall of the stator core and are uniformly arranged along the circumferential direction of the inner wall of the stator core. Any winding slot 110 extends along the axial direction of the stator core and penetrates the inner wall of the stator core along the axial direction of the stator core.

[0076] In an embodiment, the motor stator 101 of the flat wire motor 100 includes a flat wire 121 inserted into the winding slot 110. The cross section of the flat wire 121 is rectangular. The flat wires 121 in all the winding slots 110 are connected to form the stator winding. In an embodiment, the flat wire 121 is copper. The flat wire 121 can also be referred to as a conductor.

[0077] As shown in Fig. 3 and Fig. 5, L flat wires 121 can be arranged in each winding slot 110. The L flat wires 121 are arranged in layers along the radial direction R of the flat wire motor, and L=2N, where N is an integer greater than or equal to 2. The 2N flat wires 121 in each winding slot 110 are respectively referred to as L1 layer flat wire, L2 layer flat wire, L3 layer flat wire, …, L(2N-1) layer flat wire, and L(2N) layer flat wire. Adjacent two flat wires 121 in each winding slot 110 form a pair of flat wires 121. One flat wire 121 in each pair of flat wires 121 is an outer layer flat wire 122, and the other flat wire 121 in each pair of flat wires 121 is an inner layer flat wire 123. The distance between the outer layer flat wire 122 and the axial line of the flat wire motor is greater than the distance between the inner layer flat wire 123 and the axial line of the flat wire motor. Adjacent two layers of flat wires 121 in all the winding slots 110 form a circle of flat wires 120. For example, all the L1 layer flat wires and all the L2 layer flat wires in all the winding slots 110 form a first circle of flat wires 120a, all the L3 layer flat wires and all the L4 layer flat wires in all the winding slots 110 form a second circle of flat wires 120b, and so on. All the L(2N-1) layer flat wires and all the L(2N) layer flat wires in all the winding slots 110 form the Nth circle of flat wires.

[0078] Each flat wire 120 includes a plurality of pairs of flat wires 121, each pair of flat wires 121 of each flat wire 120 includes an outer layer flat wire 122 and an inner layer flat wire 123, the outer layer flat wire 122a of the first flat wire 120a is located at the L1 layer of the slot 110, the inner layer flat wire 123a of the first flat wire 120a is located at the L2 layer of the slot 110, the outer layer flat wire 122b of the second flat wire 120b is located at the L3 layer of the slot 110, the inner layer flat wire 123b of the second flat wire 120b is located at the L4 layer of the slot 110, and so on, the outer layer flat wire 122 of the Nth flat wire is located at the L(2N-1) layer of the slot 110, and the inner layer flat wire 123 of the Nth flat wire is located at the L(2N) layer of the slot 110.

[0079] As shown in FIG. 3 and FIG. 5, taking FIG. 5 as an example, the leftmost column in FIG. 5 is the layer number of the flat wire 121 in each slot 110. In an embodiment, L is 8, i.e., there are 8 layers of flat wires in each slot 110, and the 8 layers of flat wires are respectively denoted as L1 layer flat wire, L2 layer flat wire, L3 layer flat wire, L4 layer flat wire, L5 layer flat wire, L6 layer flat wire, L7 layer flat wire, and L8 layer flat wire, wherein the L1 layer flat wire is the flat wire 121 located at the bottom of the slot 110, and the L8 layer flat wire is the flat wire 121 located at the slot opening of the slot 110.

[0080] As shown in FIG. 4, in an embodiment, the flat wire 121 is part of a hairpin coil 130. In an embodiment, the hairpin coil 130 includes a plug-in segment 131 arranged in the slot 110 and a cross-segment 132 and a welding segment 133 arranged outside the slot 110, wherein the plug-in segment 131 is the flat wire 121 arranged in the slot 110. The cross-segment 132 can also be referred to as a crown end 132a, and the welding segment 133 can also be referred to as a welding end 133a. The crown end 132a and the welding end 133a are distributed at both ends of the stator core along the axial direction of the flat wire motor. The hairpin coil 130 connects two flat wires 121 through the cross-segment 132.

[0081] As shown in FIGS. 5-10, the first row of the horizontal coordinates represents the slot number of the winding slot 110. In the embodiment of the present application, the plurality of winding slots 110 of the motor stator 101 are sequentially numbered along the circumferential direction C of the flat wire motor. Each winding slot 110 corresponds to a slot number. The slot number difference between the two flat wires 121 is the slot number difference between the two flat wires 121 in the winding slot 110. In the embodiment of the present application, the span of the hairpin coil 130 refers to the slot number difference between the two flat wires 121 in the winding slot 110 of the hairpin coil 130. In the embodiment of the present application, the span of the welding layer refers to the slot number difference between the two flat wires 121 connected by the two welding sections 133. The slot number difference between the two flat wires 121 connected by the cross-wire section 132 is the slot number difference between the two flat wires 121 in the winding slot 110.

[0082] In one embodiment, the motor stator 101 of the flat wire motor 100 includes a plurality of winding slots 110 and N turns of flat wires 120. As shown in FIGS. 5-10, the N turns of flat wires 120 are arranged along the radial direction R of the flat wire motor. N is an integer greater than or equal to 2. Each turn of flat wires 120 includes a plurality of pairs of flat wires 121. The plurality of pairs of flat wires 121 in each turn of flat wires 120 are arranged along the circumferential direction C of the flat wire motor. As shown in FIG. 3, each winding slot 110 is used to accommodate a pair of flat wires 121a in each turn of flat wires 120. Each pair of flat wires 121a includes an outer layer flat wire 122 and an inner layer flat wire 123. The distance between an outer layer flat wire 122 and the axis of the flat wire motor 100 is greater than the distance between an inner layer flat wire 123 and the axis of the flat wire motor 100 along the radial direction R of the flat wire motor. An outer layer flat wire 122 in each pair of flat wires 121 of each turn of flat wires 120 is used to connect an inner layer flat wire 123 in another pair of flat wires 121. The N turns of flat wires 120 include a first turn of flat wires 120a. The outer layer flat wires 122a in the first turn of flat wires 120a include a first flat wire 1221, a second flat wire 1222, and a third flat wire 1223. The first flat wire 1221, the second flat wire 1222, and the third flat wire 1223 are connected to the respective inner layer flat wires 123a by three cross-wire sections 132 with different lengths, respectively.

[0083] In the embodiment of the present application, the N turns of flat wires 120 are arranged along the radial direction R of the flat wire motor. N is an integer greater than or equal to 2. Each turn of flat wires 120 includes a plurality of pairs of flat wires 121. The plurality of pairs of flat wires 121 in each turn of flat wires 120 are arranged along the circumferential direction C of the flat wire motor. This arrangement allows the outer layer flat wires 122 and the inner layer flat wires 123 of adjacent layers in each turn of flat wires 120 to be connected in series. This facilitates the multi-layer series connection of the windings, reduces the flat wire eddy current loss, improves the efficiency of the flat wire motor 100 at high speed, and increases the diversity of the series connection number of turns of the windings, thereby improving the performance of the flat wire motor 100.

[0084] In the embodiment of the present application, as shown in FIG. 3, each winding slot 110 is used to accommodate a pair of flat wires 121a in each coil of flat wires 120, each pair of flat wires 121a includes an outer layer flat wire 122 and an inner layer flat wire 123, the distance between the outer layer flat wire 122 and the axis of the flat wire motor 100 is greater than the distance between the inner layer flat wire 123 and the axis of the flat wire motor 100 along the radial direction R of the flat wire motor, so that the outer layer flat wire 122a of the first coil of flat wires 120a is located at the bottom layer of the winding slot 110.

[0085] As shown in FIG. 5, the flat wire 121 in the first layer of the 10th slot and the flat wire 121 in the second layer of the 10th slot are a pair of flat wires 121a, the flat wire 121 in the first layer of the 10th slot is an outer layer flat wire 122, the flat wire 121 in the second layer of the 10th slot is an inner layer flat wire 123, and the distance between the flat wire 121 in the first layer of the 10th slot and the axis of the flat wire motor 100 is greater than the distance between the flat wire 121 in the second layer of the 10th slot and the axis of the flat wire motor 100 along the radial direction R of the flat wire motor.

[0086] In the embodiment of the present application, the outer layer flat wire 122a in the first coil of flat wires 120a includes a first flat wire 1221, a second flat wire 1222 and a third flat wire 1223, and the first flat wire 1221, the second flat wire 1222 and the third flat wire 1223 are connected to the inner layer flat wire 123a corresponding to each of them respectively through three cross-wire segments 132 with different lengths, so that the winding mode of the first coil of flat wires 120a in the winding slot 110 has multiple spans, which is beneficial to realize the effect of continuous short span of the winding in the motor stator 101 of the N coils of flat wires 120, thereby weakening the harmonic magnetic field of the flat wire motor 100 and improving the NVH performance of the flat wire motor 100.

[0087] As shown in FIGS. 5 and 10, in the first coil of flat wires 120a, the length of the cross-wire segment 132 between the first flat wire 1221 of the 12th slot and the inner layer flat wire 123a of the 19th slot corresponding to it, the length of the cross-wire segment 132 between the second flat wire 1222 of the 28th slot and the inner layer flat wire 123a of the 37th slot corresponding to it, and the length of the cross-wire segment 132 between the third flat wire 1223 of the 11th slot and the inner layer flat wire 123a of the 21st slot corresponding to it are different.

[0088] As shown in FIGS. 6 and 7, in the first coil of flat wires 120a, the length of the cross-wire segment 132 between the first flat wire 1221 of the 10th slot and the inner layer flat wire 123a of the 3rd slot corresponding to it, the length of the cross-wire segment 132 between the second flat wire 1222 of the 28th slot and the inner layer flat wire 123a of the 19th slot corresponding to it, and the length of the cross-wire segment 132 between the third flat wire 1223 of the 11th slot and the inner layer flat wire 123a of the 1st slot corresponding to it are different.

[0089] As shown in FIGS. 8 and 9, in the first layer 120a, the length of the cross-line segment 132 between the first flat wire 1221 of the 10th slot and the inner layer flat wire 123a connected therewith corresponding to the 2nd slot, the length of the cross-line segment 132 between the second flat wire 1222 of the 28th slot and the inner layer flat wire 123a connected therewith corresponding to the 18th slot, and the length of the cross-line segment 132 between the third flat wire 1223 of the 11th slot and the inner layer flat wire 123a connected therewith corresponding to the 54th slot are different.

[0090] In an embodiment, the difference between the number of slots of the winding slot 110 crossed by one cross-line segment 132 connected with the third flat wire 1223 and the number of slots of the winding slot 110 crossed by one cross-line segment 132 connected with the second flat wire 1222 is 1, and the difference between the number of slots of the winding slot 110 crossed by one cross-line segment 132 connected with the second flat wire 1222 and the number of slots of the winding slot 110 crossed by one cross-line segment 132 connected with the first flat wire 1221 is 2.

[0091] In the embodiment of the present application, the number of slots of the winding slot 110 crossed by one cross-line segment 132 connected with the first flat wire 1221, one cross-line segment 132 connected with the second flat wire 1222, and one cross-line segment 132 connected with the third flat wire 1223 are different, so that the winding mode of the flat wire in the winding slot 110 has multiple spans, which is beneficial to realize the effect of continuous short distance of the winding, thereby weakening the harmonic magnetic field of the flat wire motor 100 and improving the NVH performance of the flat wire motor 100.

[0092] As shown in FIGS. 5 and 10, the number of slots of the winding slot 110 crossed by one cross-line segment 132 of the third flat wire 1223 of the 11th slot is 10, the number of slots of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot is 9, and the number of slots of the winding slot 110 crossed by one cross-line segment 132 of the first flat wire 1221 of the 12th slot is 7. The difference between the number of slots of the winding slot 110 crossed by one cross-line segment 132 of the third flat wire 1223 of the 11th slot and the number of slots of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot is 1, and the difference between the number of slots of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot and the number of slots of the winding slot 110 crossed by one cross-line segment 132 of the first flat wire 1221 of the 12th slot is 2.

[0093] As shown in FIGS. 6 and 7, the slot number of the winding slot 110 crossed by one cross-line segment 132 of the third flat wire 1223 of the 11th slot is 10, the slot number of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot is 9, and the slot number of the winding slot 110 crossed by one cross-line segment 132 of the first flat wire 1221 of the 10th slot is 7. The difference between the slot number of the winding slot 110 crossed by one cross-line segment 132 of the third flat wire 1223 of the 11th slot and the slot number of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot is 1, and the difference between the slot number of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot and the slot number of the winding slot 110 crossed by one cross-line segment 132 of the first flat wire 1221 of the 10th slot is 2.

[0094] As shown in FIGS. 8 and 9, the slot number of the winding slot 110 crossed by one cross-line segment 132 of the third flat wire 1223 of the 11th slot is 11, the slot number of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot is 10, and the slot number of the winding slot 110 crossed by one cross-line segment 132 of the first flat wire 1221 of the 10th slot is 8. The difference between the slot number of the winding slot 110 crossed by one cross-line segment 132 of the third flat wire 1223 of the 11th slot and the slot number of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot is 1, and the difference between the slot number of the winding slot 110 crossed by one cross-line segment 132 of the second flat wire 1222 of the 28th slot and the slot number of the winding slot 110 crossed by one cross-line segment 132 of the first flat wire 1221 of the 10th slot is 2.

[0095] In an embodiment, the first flat wire 1221 and the inner layer flat wire 123a connected thereto are arranged between the third flat wire 1223 and the inner layer flat wire 123a connected thereto.

[0096] In the embodiment of the present application, the first flat wire 1221 and the inner layer flat wire 123a connected thereto are arranged between the third flat wire 1223 and the inner layer flat wire 123a connected thereto, so that the slot number of the winding slot 110 crossed by the cross-line segment 132 connecting the first flat wire 1221 and the inner layer flat wire 123a connected thereto is smaller than the slot number of the winding slot 110 crossed by the cross-line segment 132 connecting the third flat wire 1223 and the inner layer flat wire 123a connected thereto, which is conducive to forming a short-pitch winding, thereby facilitating reduction of the harmonic winding coefficient and improvement of the NVH performance of the flat wire motor 100.

[0097] As shown in FIG. 5 and FIG. 10, the first flat wire 1221 of the 12th slot and the inner layer flat wire 123a connected therewith are arranged between the third flat wire 1223 of the 11th slot and the inner layer flat wire 123a connected therewith.

[0098] As shown in FIG. 6 and FIG. 7, the first flat wire 1221 of the 10th slot and the inner layer flat wire 123a connected therewith are arranged between the third flat wire 1223 of the 11th slot and the inner layer flat wire 123a connected therewith.

[0099] As shown in FIG. 8 and FIG. 9, the first flat wire 1221 of the 10th slot and the inner layer flat wire 123a connected therewith are arranged between the third flat wire 1223 of the 11th slot and the inner layer flat wire 123a connected therewith.

[0100] In an embodiment, a first flat wire 1221 and a third flat wire 1223 are arranged adjacently, and an inner layer flat wire 123a connected to the first flat wire 1221 and an inner layer flat wire 123a connected to the third flat wire 1223 are spaced apart by one winding slot 110.

[0101] In an embodiment, a first flat wire 1221 and a third flat wire 1223 are arranged adjacently, and an inner layer flat wire 123a connected to the first flat wire 1221 and an inner layer flat wire 123a connected to the third flat wire 1223 are spaced apart by one winding slot 110, so that the number of slots crossed by the cross-over segment 132 for connecting the first flat wire 1221 and the inner layer flat wire 123a connected therewith and the number of slots crossed by the cross-over segment 132 for connecting the third flat wire 1223 and the inner layer flat wire 123a connected therewith are different, which is conducive to forming a short-pitch winding, thereby being conducive to reducing the harmonic winding coefficient and improving the NVH performance of the flat wire motor 100.

[0102] As shown in FIG. 5 and FIG. 10, the first flat wire 1221 of the 12th slot and the third flat wire 1223 of the 11th slot are arranged adjacently, and the inner layer flat wire 123a of the 19th slot connected to the first flat wire 1221 of the 12th slot and the inner layer flat wire 123a of the 21st slot connected to the third flat wire 1223 of the 11th slot are spaced apart by one winding slot 110.

[0103] As shown in FIG. 6 and FIG. 7, the first flat wire 1221 of the 10th slot and the third flat wire 1223 of the 11th slot are arranged adjacently, and the inner layer flat wire 123a of the 3rd slot connected to the first flat wire 1221 of the 10th slot and the inner layer flat wire 123a of the 1st slot connected to the third flat wire 1223 of the 11th slot are spaced apart by one winding slot 110.

[0104] As shown in FIG. 8 and FIG. 9, the first flat wire 1221 of the 10th slot and the third flat wire 1223 of the 11th slot are arranged adjacently, and the inner layer flat wire 123a of the 2nd slot connected by the first flat wire 1221 of the 10th slot and the inner layer flat wire 123a of the 54th slot connected by the third flat wire 1223 of the 11th slot are spaced by one winding slot 110.

[0105] In an embodiment, the outer layer flat wire 122a in the first circle of flat wires 120a includes two third flat wires 1223, and the two third flat wires 1223 are arranged adjacently on the same side of the first flat wire 1221 along the circumferential direction C of the flat wire motor.

[0106] In the embodiment of the present application, the two third flat wires 1223 are arranged adjacently on the same side of the first flat wire 1221 along the circumferential direction C of the flat wire motor, so that the two cross wire segments 132 for connecting the two third flat wires 1223 and the inner layer flat wires 123a connected thereto respectively cross the same number of winding slots 110, so that the winding arrangement is regular, and the wire insertion process of the winding can be simplified.

[0107] As shown in FIG. 5 and FIG. 10, the third flat wire 1223 of the 10th slot and the third flat wire 1223 of the 11th slot in the first circle of flat wires 120a are arranged adjacently on the same side of the first flat wire 1221 of the 12th slot along the circumferential direction C of the flat wire motor.

[0108] As shown in FIG. 6 to FIG. 9, the third flat wire 1223 of the 11th slot and the third flat wire 1223 of the 12th slot in the first circle of flat wires 120a are arranged adjacently on the same side of the first flat wire 1221 of the 10th slot along the circumferential direction C of the flat wire motor.

[0109] In an embodiment, one inner layer flat wire 123a connected by one first flat wire 1221 or one third flat wire 1223 and one second flat wire 1222 are arranged adjacently in the same winding slot 110 along the radial direction R of the flat wire motor.

[0110] In the embodiment of the present application, one inner layer flat wire 123a connected by one first flat wire 1221 or one third flat wire 1223 and one second flat wire 1222 are arranged adjacently in the same winding slot 110 along the radial direction R of the flat wire motor, which is beneficial to make each circle of flat wires 120 traverse in the winding slot 110, so as to maintain the potential balance and avoid circulating current.

[0111] As shown in FIG. 5 and FIG. 10, the inner layer flat wire 123a of the 19th slot connected by the first flat wire 1221 of the 12th slot and the second flat wire 1222 of the 19th slot are arranged in the same winding slot 110 along the radial direction R of the flat wire motor. The inner layer flat wire 123a of the 21st slot connected by the third flat wire 1223 of the 11th slot and the second flat wire 1222 of the 21st slot are arranged in the same winding slot 110 along the radial direction R of the flat wire motor.

[0112] In an embodiment, the outer layer flat wire 122a in the first circle of flat wires 120a includes a plurality of second flat wires 1222, the plurality of second flat wires 1222 are sequentially and adjacently arranged along the circumferential direction C of the flat wire motor, and the plurality of second flat wires 1222 and the inner layer flat wire 123a connected thereto are connected by the same cross-over segment 132.

[0113] In the embodiment of the present application, the plurality of second flat wires 1222 are sequentially and adjacently arranged along the circumferential direction C of the flat wire motor, and the plurality of second flat wires 1222 and the inner layer flat wire 123a connected thereto are connected by the same cross-over segment 132, so that the winding wire arrangement is regular, and the winding wire insertion process can be simplified.

[0114] As shown in FIG. 5 and FIG. 10, the second flat wire 1222 of the 28th slot and the inner layer flat wire 123a of the 37th slot connected thereto, the second flat wire 1222 of the 29th slot and the inner layer flat wire 123a of the 38th slot connected thereto, and the second flat wire 1222 of the 30th slot and the inner layer flat wire 123a of the 39th slot connected thereto are connected by the same cross-over segment 132.

[0115] As shown in FIG. 6 and FIG. 7, the second flat wire 1222 of the 28th slot and the inner layer flat wire 123a of the 19th slot connected thereto, the second flat wire 1222 of the 29th slot and the inner layer flat wire 123a of the 20th slot connected thereto, and the second flat wire 1222 of the 30th slot and the inner layer flat wire 123a of the 21st slot connected thereto are connected by the same cross-over segment 132.

[0116] As shown in FIG. 8 and FIG. 9, the second flat wire 1222 of the 28th slot and the inner layer flat wire 123a of the 18th slot connected thereto, the second flat wire 1222 of the 29th slot and the inner layer flat wire 123a of the 19th slot connected thereto, and the second flat wire 1222 of the 30th slot and the inner layer flat wire 123a of the 20th slot connected thereto are connected by the same cross-over segment 132.

[0117] In an embodiment, the N layers of flat wires 120 further include a second layer of flat wires 120b, the second layer of flat wires 120b is arranged adjacent to the first layer of flat wires 120a along the radial direction R of the flat motor, the distance between the outer layer flat wires 122a in the first layer of flat wires 120a and the axis of the flat motor 100 is greater than the distance between the outer layer flat wires 122b in the second layer of flat wires 120b and the axis of the flat motor 100, and one inner layer flat wire 123a in the first layer of flat wires 120a is used to fixedly connect one outer layer flat wire 122b in the second layer of flat wires 120b through one cross wire segment 132.

[0118] In the embodiment of the present application, the distance between the outer layer flat wires 122a in the first layer of flat wires 120a and the axis of the flat motor 100 is greater than the distance between the outer layer flat wires 122b in the second layer of flat wires 120b and the axis of the flat motor 100, that is, the first layer of flat wires 120a is a layer of flat wires located close to the bottom of the slot 110.

[0119] In the embodiment of the present application, one inner layer flat wire 123a in the first layer of flat wires 120a is used to fixedly connect one outer layer flat wire 122b in the second layer of flat wires 120b through one cross wire segment 132, so as to realize the series connection of the first layer of flat wires 120a and the second layer of flat wires 120b, which is beneficial to realize the multi-layer series connection of the winding, reduce the flat wire eddy current loss, improve the efficiency of the flat motor 100 at high speed, and increase the diversity of the series turns of the winding and improve the performance of the flat motor 100.

[0120] As shown in FIG. 5, the inner layer flat wire 123a of the 3rd slot in the first layer of flat wires 120a is used to fixedly connect the outer layer flat wire 122b of the 11th slot in the second layer of flat wires 120b through one cross wire segment 132.

[0121] As shown in FIG. 6 and FIG. 7, the inner layer flat wire 123a of the 19th slot in the first layer of flat wires 120a is used to fixedly connect the outer layer flat wire 122b of the 10th slot in the second layer of flat wires 120b through one cross wire segment 132.

[0122] As shown in FIG. 8 and FIG. 9, the inner layer flat wire 123a of the 18th slot in the first layer of flat wires 120a is used to fixedly connect the outer layer flat wire 122b of the 10th slot in the second layer of flat wires 120b through one cross wire segment 132.

[0123] As shown in FIG. 10, the inner layer flat wire 123a of the 1st slot in the first layer of flat wires 120a is used to fixedly connect the outer layer flat wire 122b of the 10th slot in the second layer of flat wires 120b through one cross wire segment 132.

[0124] In an embodiment, the length of the cross-line segment 132 between the inner layer flat wire 123a of the first circle of flat wires 120a and the outer layer flat wire 122b of the second circle of flat wires 120b connected thereto is less than or equal to the length of the cross-line segment 132 between the third flat wire 1223 of the first circle of flat wires 120a and the inner layer flat wire 123a connected thereto.

[0125] In the embodiment, the length of the cross-line segment 132 between the inner layer flat wire 123a of the first circle of flat wires 120a and the outer layer flat wire 122b of the second circle of flat wires 120b connected thereto is less than the length of the cross-line segment 132 between the third flat wire 1223 of the first circle of flat wires 120a and the inner layer flat wire 123a connected thereto, which is conducive to forming a short-circuit winding, achieving the effect of continuous short distance of the winding, thereby weakening the harmonic magnetic field of the flat wire motor 100 and improving the NVH performance of the flat wire motor 100.

[0126] As shown in FIG. 5, the cross-line segment 132 between the inner layer flat wire 123a of the 3rd slot in the first circle of flat wires 120a and the outer layer flat wire 122b of the 11th slot in the second circle of flat wires 120b connected thereto crosses 8 slots of the winding slot 110, and the cross-line segment 132 between the third flat wire 1223 of the 10th slot in the first circle of flat wires 120a and the inner layer flat wire 123a of the 20th slot connected thereto crosses 10 slots of the winding slot 110, and thus the length of the cross-line segment 132 between the inner layer flat wire 123a of the 3rd slot in the first circle of flat wires 120a and the outer layer flat wire 122b of the 11th slot in the second circle of flat wires 120b connected thereto is less than the length of the cross-line segment 132 between the third flat wire 1223 of the 10th slot in the first circle of flat wires 120a and the inner layer flat wire 123a of the 20th slot connected thereto.

[0127] As shown in FIG. 6 and FIG. 7, the cross-line segment 132 between the inner layer flat wire 123a of the 19th slot in the first circle of flat wires 120a and the outer layer flat wire 122b of the 10th slot in the second circle of flat wires 120b connected thereto crosses 9 slots of the winding slot 110, and the cross-line segment 132 between the third flat wire 1223 of the 11th slot in the first circle of flat wires 120a and the inner layer flat wire 123a of the 1st slot connected thereto crosses 10 slots of the winding slot 110, and thus the length of the cross-line segment 132 between the inner layer flat wire 123a of the 19th slot in the first circle of flat wires 120a and the outer layer flat wire 122b of the 10th slot in the second circle of flat wires 120b connected thereto is less than the length of the cross-line segment 132 between the third flat wire 1223 of the 11th slot in the first circle of flat wires 120a and the inner layer flat wire 123a of the 1st slot connected thereto.

[0128] As shown in FIG. 8 and FIG. 9, the number of slots of the winding slots 110 crossed by the cross-over section 132 between the inner layer flat wire 123a of the 18th slot in the first circle flat wire 120a and the outer layer flat wire 122b of the 10th slot in the second circle flat wire 120b connected thereto is 8, and the number of slots of the winding slots 110 crossed by the cross-over section 132 between the third flat wire 1223 of the 11th slot of the first circle flat wire 120a and the inner layer flat wire 123a of the 54th slot connected thereto is 11, thus, the length of the cross-over section 132 between the inner layer flat wire 123a of the 18th slot in the first circle flat wire 120a and the outer layer flat wire 122b of the 10th slot in the second circle flat wire 120b connected thereto is less than the length of the cross-over section 132 between the third flat wire 1223 of the 11th slot of the first circle flat wire 120a and the inner layer flat wire 123a of the 54th slot connected thereto.

[0129] In the embodiment of the present application, the length of the cross-over section 132 between one inner layer flat wire 123a of the first circle flat wire 120a and one outer layer flat wire 122b of the second circle flat wire 120b connected thereto is equal to the length of the cross-over section 132 between one third flat wire 1223 of the first circle flat wire 120a and one inner layer flat wire 123a connected thereto, which is conducive to reducing the types of the length of the cross-over section 132 and simplifying the wire winding process.

[0130] As shown in FIG. 10, the number of slots of the winding slots 110 crossed by the cross-over section 132 between the inner layer flat wire 123a of the 10th slot in the first circle flat wire 120a and the outer layer flat wire 122b of the 20th slot in the second circle flat wire 120b connected thereto is 10, and the number of slots of the winding slots 110 crossed by the cross-over section 132 between the third flat wire 1223 of the 1st slot of the first circle flat wire 120a and the inner layer flat wire 123a of the 11th slot connected thereto is 10, thus, the length of the cross-over section 132 between the inner layer flat wire 123a of the 10th slot in the first circle flat wire 120a and the outer layer flat wire 122b of the 20th slot in the second circle flat wire 120b connected thereto is equal to the length of the cross-over section 132 between the third flat wire 1223 of the 1st slot of the first circle flat wire 120a and the inner layer flat wire 123a of the 11th slot connected thereto.

[0131] In one embodiment, the difference between the number of slots of the winding slots 110 crossed by the cross-over section 132 between one third flat wire 1223 of the first circle flat wire 120a and one inner layer flat wire 123a connected thereto and the number of slots of the winding slots 110 crossed by the cross-over section 132 between one inner layer flat wire 123a of the first circle flat wire 120a and one outer layer flat wire 122b of the second circle flat wire 120b connected thereto is 1 or 2 or 3.

[0132] In the embodiment of the present application, the difference between the slot number of the winding slot 110 crossed by the cross-over segment 132 between the third flat wire 1223 of the first circle of flat wires 120a and the inner layer flat wire 123a connected thereto and the slot number of the winding slot 110 crossed by the cross-over segment 132 between the inner layer flat wire 123a of the first circle of flat wires 120a and the outer layer flat wire 122b of the second circle of flat wires 120b connected thereto is 1 or 2 or 3, so that the connection of the flat wires 121 in the winding can have more diverse connection modes, providing more winding routing schemes. It is also beneficial to increase the diversity of the series turns of the winding, and to improve the performance of the flat wire motor 100.

[0133] As shown in FIGS. 6 and 7, the slot number of the winding slot 110 crossed by the cross-over segment 132 between the inner layer flat wire 123a of the 19th slot in the first circle of flat wires 120a and the outer layer flat wire 122b of the 10th slot in the second circle of flat wires 120b connected thereto is 9, the slot number of the winding slot 110 crossed by the cross-over segment 132 between the third flat wire 1223 of the 11th slot of the first circle of flat wires 120a and the inner layer flat wire 123a of the 1st slot connected thereto is 10, and the difference between the slot number of the winding slot 110 crossed by the cross-over segment 132 between the third flat wire 1223 of the 11th slot of the first circle of flat wires 120a and the inner layer flat wire 123a of the 1st slot connected thereto and the slot number of the winding slot 110 crossed by the cross-over segment 132 between the inner layer flat wire 123a of the 19th slot in the first circle of flat wires 120a and the outer layer flat wire 122b of the 10th slot in the second circle of flat wires 120b connected thereto is 1.

[0134] As shown in FIG. 5, the slot number of the winding slot 110 crossed by the cross-over segment 132 between the inner layer flat wire 123a of the 3rd slot in the first circle of flat wires 120a and the outer layer flat wire 122b of the 11th slot in the second circle of flat wires 120b connected thereto is 8, the slot number of the winding slot 110 crossed by the cross-over segment 132 between the third flat wire 1223 of the 10th slot of the first circle of flat wires 120a and the inner layer flat wire 123a of the 20th slot connected thereto is 10, and the difference between the slot number of the winding slot 110 crossed by the cross-over segment 132 between the third flat wire 1223 of the 10th slot of the first circle of flat wires 120a and the inner layer flat wire 123a of the 20th slot connected thereto and the slot number of the winding slot 110 crossed by the cross-over segment 132 between the inner layer flat wire 123a of the 3rd slot in the first circle of flat wires 120a and the outer layer flat wire 122b of the 11th slot in the second circle of flat wires 120b connected thereto is 2.

[0135] As shown in FIGS. 8 and 9, the number of slots of the winding slots 110 crossed by the cross-over section 132 between the inner layer flat wire 123a of the 18th slot in the first circle flat wire 120a and the outer layer flat wire 122b of the 10th slot in the second circle flat wire 120b connected thereto is 8, the number of slots of the winding slots 110 crossed by the cross-over section 132 between the third flat wire 1223 of the 11th slot of the first circle flat wire 120a and the inner layer flat wire 123a of the 54th slot connected thereto is 11, and the difference between the number of slots of the winding slots 110 crossed by the cross-over section 132 between the third flat wire 1223 of the 11th slot of the first circle flat wire 120a and the inner layer flat wire 123a of the 54th slot connected thereto and the number of slots of the winding slots 110 crossed by the cross-over section 132 between the inner layer flat wire 123a of the 18th slot in the first circle flat wire 120a and the outer layer flat wire 122b of the 10th slot in the second circle flat wire 120b connected thereto is 3.

[0136] In an embodiment, the outer layer flat wire 122b in the second circle flat wire 120b includes a first flat wire 1224, a second flat wire 1225 and a third flat wire 1226, and the number of slots of the winding slots 110 crossed by the cross-over section 132 between the first flat wire 1221 in the first circle flat wire 120a and one inner layer flat wire 123a connected thereto is equal to the number of slots of the winding slots 110 crossed by the cross-over section 132 between the first flat wire 1224 in the second circle flat wire 120b and one inner layer flat wire 123b connected thereto.

[0137] In the embodiment of the present application, the number of slots of the winding slots 110 crossed by the cross-over section 132 between the first flat wire 1221 in the first circle flat wire 120a and one inner layer flat wire 123a connected thereto is equal to the number of slots of the winding slots 110 crossed by the cross-over section 132 between the first flat wire 1224 in the second circle flat wire 120b and one inner layer flat wire 123b connected thereto, which is conducive to making the two circle flat wires 120a, 120b in the winding slots 110 have the same cross-over connection mode, thereby facilitating the winding to be more regular and the appearance to be better, and also facilitating the winding process to be simplified and the automatic winding to be facilitated.

[0138] As shown in FIG. 5, the number of slots of the winding slots 110 crossed by the cross-over section 132 between the first flat wire 1221 of the 12th slot in the first circle flat wire 120a and the inner layer flat wire 123a of the 19th slot connected thereto is 7, the number of slots of the winding slots 110 crossed by the cross-over section 132 between the first flat wire 1224 of the 11th slot in the second circle flat wire 120b and the inner layer flat wire 123b of the 18th slot connected thereto is 7, and the number of slots of the winding slots 110 crossed by the cross-over sections 132 of the two is the same.

[0139] As shown in FIG. 6, the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1221 of the 10th slot in the first circle of flat wires 120a and the inner layer flat wire 123a of the 3rd slot connected therewith is 7, the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1224 of the 9th slot in the second circle of flat wires 120b and the inner layer flat wire 123b of the 2nd slot connected therewith is 7, and the slot numbers of the winding slots 110 crossed by the two cross-line segments 132 are the same.

[0140] As shown in FIG. 8 and FIG. 9, the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1221 of the 10th slot in the first circle of flat wires 120a and the inner layer flat wire 123a of the 2nd slot connected therewith is 8, the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1224 of the 9th slot in the second circle of flat wires 120b and the inner layer flat wire 123b of the 1st slot connected therewith is 8, and the slot numbers of the winding slots 110 crossed by the two cross-line segments 132 are the same.

[0141] In an embodiment, the outer layer flat wire 122 in the second circle of flat wires 120b includes the first flat wire 1224, the second flat wire 1225 and the third flat wire 1226, the difference between the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1221 in the first circle of flat wires 120a and one inner layer flat wire 123a connected therewith and the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1224 in the second circle of flat wires 120b and one inner layer flat wire 123b connected therewith is 1.

[0142] In the embodiments of the present application, the difference between the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1221 in the first circle of flat wires 120a and one inner layer flat wire 123a connected therewith and the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1224 in the second circle of flat wires 120b and one inner layer flat wire 123b connected therewith is 1, which is conducive to making the second circle of flat wires 120b and the first flat wire 1221 in the first circle of flat wires 120a and one inner layer flat wire 123a connected therewith in the winding slots 110 have different cross distances, thereby being conducive to forming a short-pitch winding and being conducive to realizing the effect of continuous short pitch of the winding in the motor stator 101 of the multi-circle flat wire 120, thereby weakening the harmonic magnetic field of the flat wire motor 100 and improving the NVH performance of the flat wire motor 100.

[0143] As shown in FIG. 10, the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1221 in the 12th slot in the first flat wire 120a and the inner layer flat wire 123a in the 19th slot connected therewith is 7, the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1224 in the 12th slot in the second flat wire 120b and the inner layer flat wire 123b in the 18th slot connected therewith is 6, and the difference between the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1221 in the 12th slot in the first flat wire 120a and the inner layer flat wire 123a in the 19th slot connected therewith and the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1224 in the 12th slot in the second flat wire 120b and the inner layer flat wire 123b in the 18th slot connected therewith is 1.

[0144] In an embodiment, the outer layer flat wire 122 in the second flat wire 120b includes the first flat wire 1224, the second flat wire 1225 and the third flat wire 1226, and the difference between the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1224 in the second flat wire 120b and one inner layer flat wire 123b connected therewith and the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1221 in the first flat wire 120a and one inner layer flat wire 123a connected therewith is 1.

[0145] In the embodiment, the difference between the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1224 in the second flat wire 120b and one inner layer flat wire 123b connected therewith and the slot number of the winding slots 110 crossed by one cross-line segment 132 between the first flat wire 1221 in the first flat wire 120a and one inner layer flat wire 123a connected therewith is 1, which is conducive to making the second flat wire 120b and the first flat wire 1224 in the first flat wire 120a and one inner layer flat wire 123b connected therewith in the winding slots 110 have different cross distances, thereby being conducive to forming a short-pitch winding and being conducive to realizing the effect of continuous short-pitch winding in the motor stator 101 of the multi-turn flat wire 120, thereby weakening the harmonic magnetic field of the flat wire motor 100 and improving the NVH performance of the flat wire motor 100.

[0146] As shown in Fig. 7, the number of slots of the winding slots 110 crossed by one cross wire segment 132 between the first flat wire 1221 of the 10th slot in the first flat wire 120a and the inner layer flat wire 123a of the 3rd slot connected therewith is 7, the number of slots of the winding slots 110 crossed by one cross wire segment 132 between the first flat wire 1224 of the 10th slot in the second flat wire 120b and the inner layer flat wire 123b of the 2nd slot connected therewith is 8, and the difference between the number of slots of the winding slots 110 crossed by one cross wire segment 132 between the first flat wire 1224 of the 10th slot in the second flat wire 120b and the inner layer flat wire 123b of the 2nd slot connected therewith and the number of slots of the winding slots 110 crossed by one cross wire segment 132 between the first flat wire 1221 of the 10th slot in the first flat wire 120a and the inner layer flat wire 123a of the 3rd slot connected therewith is 1.

[0147] In an embodiment, the flat wire motor 100 is an m-phase motor, the stator core contains Z winding slots 110, the number of stator winding magnetic poles and the number of rotor poles is 2p, p is a positive integer, p represents the number of pole pairs, and the number of slots per pole per phase q=3, wherein q=Z / (2mp).

[0148] In an embodiment, L layers of flat wires 121 are arranged in each winding slot 110, L is an even number, L=2N, N is an integer greater than or equal to 2, and the number of parallel branches=1 or 2 or 4.

[0149] In an embodiment, L is decomposed into the sum of three positive integers T1, T2, and T3, i.e., L=T1+T2+T3, and the three positive integers T1, T2, and T3 are not all equal, the T1 layers of flat wires 121 are divided into a group, the T2 layers of flat wires 121 are divided into a group, and the T3 layers of flat wires 121 are divided into another group, the T2 layers of flat wires 121 are offset by 1 winding slot 110 clockwise relative to the T1 layers of flat wires 121 along the circumferential direction C of the flat wire motor, and the T3 layers of flat wires 121 are offset by 1 winding slot 110 relative to the T2 layers of flat wires 121 along the same direction, so as to realize the effect of continuous short pitch of the winding.

[0150] In an embodiment, the hairpin coil 130 is connected between 1 / 2 layers, 3 / 4 layers, 5 / 6 layers, …, L-1 layers / L layers.

[0151] In an embodiment, the adjacent layer hairpin coil 130 includes three kinds of spans, Z / 2p, Z / 2p+1, Z / 2p-q+1 or Z / 2p-1, Z / 2p, Z / 2p-q or Z / 2p+1, Z / 2p+2, Z / 2p-q+2. Z / 2p refers to the span of the integral pitch. Wherein, the span of the adjacent two layers of hairpin coils 130 refers to the number of slots of the winding slots 110 crossed by the cross wire segment of the adjacent two layers of hairpin coils 130, which is also the difference between the slot numbers of the winding slots 110 where the two flat wires 121 of the hairpin coil 130 are located.

[0152] In an embodiment, the total hairpin coil 130 line type is 3*L / 2.

[0153] In an embodiment, the welding layer span is Z / 2p or Z / 2p-1 or Z / 2p+1. The span of two adjacent welding layers refers to the slot number of the winding slot 110 spanned by the adjacent welding layers, and is also the difference between the slot numbers of the two winding slots 110 where the two welding sections 133 of the adjacent layers are connected.

[0154] In an embodiment, the phase winding lead of the stator winding adopts Y-type connection.

[0155] In an embodiment, the phase winding lead of the stator winding adopts Δ-type connection.

[0156] In the embodiments of the present application, the winding arrangement is applicable to both even layers with L / 2=odd number and even layers with L / 2=even number, which widens the flexibility of winding design. The plurality of flat wire groups are staggered by 1 winding slot 110, which is equivalent to continuous short distance, and can weaken the 6k±1 (k=1 or 2) harmonic of the winding 6k±1 (k=1 or 2) and improve the NVH performance. Each flat wire 121 in each parallel sub-winding of each phase is uniformly distributed in different layers of each winding slot 110, and the counter electromotive force and current of each parallel sub-winding are completely the same, which eliminates the additional copper loss caused by winding parallel, ensures the uniformity of winding temperature, and improves the service life of the motor. The phase lead is located at the first layer or the Lth layer, which can fully utilize the radial space and simplify the Busbar structure. The hairpin coils 130 of each layer are independent of each other, and there is no additional cross-layer hairpin coil 130, so that the full-automatic insertion can be realized through independent wire cups, the manufacturing process is simplified, and mass production is facilitated.

[0157] In the embodiments of the present application, the flat wires at the 1st / 2nd layer constitute the first circle of flat wires, the flat wires at the 3rd / 4th layer constitute the second circle of flat wires, and the flat wires at the 5th / 6th layer constitute the third circle of flat wires, and the flat wires at the L-1th / Lth layer constitute the Nth circle of flat wires.

[0158] FIG. 11 is a schematic diagram of the end connection of the three-phase winding according to an embodiment of the present application, and FIG. 12 is another schematic diagram of the end connection of the three-phase winding according to an embodiment of the present application.

[0159] In one embodiment, a three-phase flat wire motor, the stator winding is divided into U phase, V phase and W phase, and the number of parallel branches of each phase winding is 2. As shown in Figure 11, the three-phase winding of the stator winding is composed of two parallel circuits respectively, the two parallel branches of the U phase winding are marked as U1 and U2, the two parallel branches of the V phase winding are marked as V1 and V2, and the two parallel branches of the W phase winding are marked as W1 and W2. The ends of the U phase, the V phase and the W phase are connected in Y type. In another embodiment, as shown in Figure 12, the three-phase winding of the stator winding is composed of two parallel circuits respectively, and the ends of the U phase, the V phase and the W phase are connected in Δ type.

[0160] The connection mode of the specific parallel branch of the embodiment of the application will be described in detail below in combination with specific embodiments.

[0161] In Figures 5 to 10, the winding structure is described as follows: the first row in Figures 7 to 10 is the slot number of the winding slot, and the first column is the layer number of the flat wire in each winding slot. Taking Figure 5 as an example, the motor stator has 54 winding slots, and 8 layers can be arranged in each winding slot. The 1st layer is the flat wire at the bottom of the winding slot, and the 8th layer is the flat wire at the slot opening. "-" represents the current flowing into the flat wire, "+" represents the current flowing out of the flat wire, U1 represents the first parallel branch, U 1in represents the first parallel branch of the first end lead-out wire, U 1out represents the first parallel branch of the tail end lead-out wire. U2 represents the second parallel branch, U 2in represents the first parallel branch of the first end lead-out wire, U 2out represents the first parallel branch of the tail end lead-out wire. It should be noted that the phase distribution in Figures 5 to 10 is only exemplary. By reversing the "+" "-" symbols in Figures 5 to 10, for example, changing "U+" in Figures 5 to 10 to "U-", and changing "U-" to "U+", and making corresponding modifications to the V phase and the W phase, all of which are within the scope of the present application.

[0162] In one embodiment, the winding slot of the stator core is Z=54, the number of stator winding poles and the number of rotor poles is 2p=6, the number of slots per phase per pole q=Z / (2mp)=3, the number of layers of flat wire in the winding slot L=8, and the stator winding is divided into U phase, V phase and W phase. The number of parallel branches of each phase winding is 2. Figure 5 is a connection diagram of the two parallel branches of the U phase of the embodiment.

[0163] As shown in Figures 5 and 3, each winding slot contains L=8 layers of flat wire, the 1st layer is marked as L1, the 2nd layer is marked as L2, the 3rd layer is marked as L3, the 4th layer is marked as L4, the 5th layer is marked as L5, the 6th layer is marked as L6, the 7th layer is marked as L7, and the 8th layer is marked as L8. The 1st layer is the bottom layer of the winding slot, and the 8th layer is the slot opening layer.

[0164] Each parallel branch in Fig. 5 traverses the position of the flat wire layer that can be arranged, so the number of each parallel branch can keep the potential balance and will not produce circulating current. The 8 layers of flat wires are divided into 3 groups, T1, T2, T3 take 2, 4, 2 respectively, that is, T1 contains the first 1 / 2 layer of flat wires, T2 contains the 3rd / 4th / 5th / 6th layer of flat wires, and T3 contains the 7th / 8th layer of flat wires. The flat wires of the T2 layer are staggered by one winding slot in the clockwise direction of the flat wire motor relative to the flat wires of the T1 layer, and the flat wires of the T3 layer are staggered by one winding slot in the same direction relative to the flat wires of the T2 layer, so that the winding realizes the effect of continuous short distance. The flat wires belonging to the same parallel branch are connected in sequence between each group to form the sub-branch of the branch.

[0165] For example, the first sub-branch of the first branch of the U phase starts from the first layer of the 12th slot, and after connecting all the flat wires belonging to the first branch of the first / second layer, the tail end lead-out wire is led out from the second layer of the 3rd slot. During this process, three kinds of hairpin coils with spans of Z / 2p-q+1=7, Z / 2p=9, and Z / 2p+1=10 are used.

[0166] The first sub-branch of the first branch of the U phase starts from the first layer of the 12th slot, and after connecting all the flat wires belonging to the first / second layer, the tail end lead-out wire is led out from the second layer of the 3rd slot. During this process, three kinds of hairpin coils with spans of Z / 2p-q+1=7, Z / 2p=9, and Z / 2p+1=10 are used.

[0167] The first sub-branch of the first branch of the U phase starts from the first layer of the 12th slot, and after connecting all the flat wires belonging to the first / second layer, the tail end lead-out wire is led out from the second layer of the 3rd slot. During this process, three kinds of hairpin coils with spans of Z / 2p-q+1=7, Z / 2p=9, and Z / 2p+1=10 are used.

[0168] The first sub-branch of the first branch of the U phase starts from the first layer of the 12th slot, and after connecting all the flat wires belonging to the first / second layer, the tail end lead-out wire is led out from the second layer of the 3rd slot. During this process, three kinds of hairpin coils with spans of Z / 2p-q+1=7, Z / 2p=9, and Z / 2p+1=10 are used.

[0169] From the four sub-branches of the first branch, it can be known that the total number of hairpin coils is 3*L / 2=12.

[0170] The first, second, third, and fourth sub-branches of the second branch of the U phase can be arranged by referring to the first branch of the U phase, and details are not repeated here.

[0171] The single cross-layer cross-line segment is used to realize cross-layer, connect the first, second, third and fourth sub-branch coils, and the cross-layer cross-line segments between layers can be equal or not equal. In the embodiment one shown in FIG. 5, the cross-layer cross-line segment cross-layer distance of the second layer to the third layer and the sixth layer to the seventh layer is Z / 2p-1=8, and the cross-layer cross-line segment cross-layer distance of the fourth layer to the fifth layer is Z / 2p=9. In addition to the cross-layer cross-line segment, the welding end of each sub-branch has the same cross-layer distance, which is Z / 2p=9 in the embodiment one shown in FIG. 5, which can simplify the process of twisting, welding and coating.

[0172] As shown in FIG. 5, the T1 layer flat wire, the T2 layer flat wire and the T3 layer flat wire respectively include different phase belts, each phase belt includes three winding slots arranged adjacently, the phase belt of the T2 layer flat wire is staggered by one winding slot relative to the phase belt of the T1 layer flat wire, and the phase belt of the T3 layer flat wire is staggered by one winding slot relative to the phase belt of the T2 layer flat wire. For example, in the T1 layer flat wire, the 1 / 2 layer flat wire in the 10th slot, the 11th slot and the 12th slot is a phase belt, in the T2 layer flat wire, the 3 / 4 / 5 / 6 layer flat wire in the 9th slot, the 10th slot and the 11th slot is a phase belt, and in the T3 layer flat wire, the 7 / 8 layer flat wire in the 8th slot, the 9th slot and the 10th slot is a phase belt.

[0173] As shown in FIG. 5, the solid line represents the connection mode of the crown end of the hairpin coil or the cross-line segment, and the dashed line represents the connection mode of the welding end of the hairpin coil or the welding segment.

[0174] The connection mode of the U-phase two parallel branches in the embodiment of the present application will be described in detail below in combination with FIG. 5. The connection mode of the stator winding at the crown end will be described below according to the solid line connection mode in FIG. 5, and the connection mode of the welding end of the stator winding can be referred to the dashed line connection mode.

[0175] As shown in FIG. 5, the first sub-branch of the first branch of the U-phase has a first end lead-out wire starting from the 12th slot and the 1st layer as an incoming wire end U 1in From the 1st layer of the 12th slot, from the 2nd layer of the 19th slot, then from the 1st layer of the 28th slot, from the 2nd layer of the 37th slot, then from the 1st layer of the 46th slot, from the 2nd layer of the 1st slot, then from the 1st layer of the 10th slot, from the 2nd layer of the 20th slot, then from the 1st layer of the 29th slot, from the 2nd layer of the 38th slot, then from the 1st layer of the 47th slot, from the 2nd layer of the 2nd slot, then from the 1st layer of the 11th slot, from the 2nd layer of the 21st slot, then from the 1st layer of the 30th slot, from the 2nd layer of the 39th slot, then from the 1st layer of the 48th slot, from the 2nd layer of the 3rd slot, and thus the traversal of the 1st layer and the 2nd layer flat wires is completed.

[0176] The first sub-branch of the U-phase first branch starts from the 11th slot of the 3rd layer, enters from the 3rd layer of the 11th slot, exits from the 4th layer of the 18th slot, then enters from the 3rd layer of the 27th slot, exits from the 4th layer of the 36th slot, then enters from the 3rd layer of the 45th slot, exits from the 4th layer of the 54th slot, then enters from the 3rd layer of the 9th slot, exits from the 4th layer of the 19th slot, then enters from the 3rd layer of the 28th slot, exits from the 4th layer of the 37th slot, then enters from the 3rd layer of the 46th slot, exits from the 4th layer of the 1st slot, then enters from the 3rd layer of the 10th slot, exits from the 4th layer of the 20th slot, then enters from the 3rd layer of the 29th slot, exits from the 4th layer of the 38th slot, then enters from the 3rd layer of the 47th slot, exits from the 4th layer of the 2nd slot, thus completing the traversal of the flat wires of the 3rd layer and the 4th layer.

[0177] The third sub-branch of the U-phase first branch starts from the 11th slot of the 5th layer, enters from the 5th layer of the 11th slot, exits from the 6th layer of the 18th slot, then enters from the 5th layer of the 27th slot, exits from the 6th layer of the 36th slot, then enters from the 5th layer of the 45th slot, exits from the 6th layer of the 54th slot, then enters from the 5th layer of the 9th slot, exits from the 6th layer of the 19th slot, then enters from the 5th layer of the 28th slot, exits from the 6th layer of the 37th slot, then enters from the 5th layer of the 46th slot, exits from the 6th layer of the 1st slot, then enters from the 5th layer of the 10th slot, exits from the 6th layer of the 20th slot, then enters from the 5th layer of the 29th slot, exits from the 6th layer of the 38th slot, then enters from the 5th layer of the 47th slot, exits from the 6th layer of the 2nd slot, thus completing the traversal of the flat wires of the 5th layer and the 6th layer.

[0178] The fourth sub-branch of the U-phase first branch starts from the 10th slot of the 7th layer, enters from the 7th layer of the 10th slot, exits from the 8th layer of the 17th slot, then enters from the 7th layer of the 26th slot, exits from the 8th layer of the 35th slot, then enters from the 7th layer of the 44th slot, exits from the 8th layer of the 53rd slot, then enters from the 7th layer of the 8th slot, exits from the 8th layer of the 18th slot, then enters from the 7th layer of the 27th slot, exits from the 8th layer of the 36th slot, then enters from the 7th layer of the 45th slot, exits from the 8th layer of the 54th slot, then enters from the 7th layer of the 9th slot, exits from the 8th layer of the 19th slot, then enters from the 7th layer of the 28th slot, exits from the 8th layer of the 37th slot, then enters from the 7th layer of the 46th slot, exits from the 8th layer of the 1st slot, thus completing the traversal of the flat wires of the 7th layer and the 8th layer.

[0179] Thus, the outgoing line end U 1out .

[0180] As shown in FIG. 5, the first sub-branch of the U-phase second branch starts from the 10th slot of the 8th layer as an incoming line end U 2inThe first sub-branch of the first branch of the U-phase starts from the 11th slot of the 6th layer, enters from the 11th slot of the 6th layer, and exits from the 1st slot of the 5th layer, then enters from the 46th slot of the 6th layer, exits from the 37th slot of the 5th layer, then enters from the 28th slot of the 6th layer, exits from the 19th slot of the 5th layer, then enters from the 10th slot of the 6th layer, exits from the 54th slot of the 5th layer, then enters from the 45th slot of the 6th layer, exits from the 36th slot of the 5th layer, then enters from the 27th slot of the 6th layer, exits from the 18th slot of the 5th layer, then enters from the 9th slot of the 6th layer, exits from the 2nd slot of the 5th layer, then enters from the 47th slot of the 6th layer, exits from the 38th slot of the 5th layer, then enters from the 29th slot of the 6th layer, exits from the 20th slot of the 5th layer, and thus the traversal of the flat wires of the 5th and 6th layers is completed.

[0181] The second sub-branch of the first branch of the U-phase starts from the 11th slot of the 4th layer, enters from the 11th slot of the 4th layer, and exits from the 1st slot of the 3rd layer, then enters from the 46th slot of the 4th layer, exits from the 37th slot of the 3rd layer, then enters from the 28th slot of the 4th layer, exits from the 19th slot of the 3rd layer, then enters from the 10th slot of the 4th layer, exits from the 54th slot of the 3rd layer, then enters from the 45th slot of the 4th layer, exits from the 36th slot of the 3rd layer, then enters from the 27th slot of the 4th layer, exits from the 18th slot of the 3rd layer, then enters from the 9th slot of the 4th layer, exits from the 2nd slot of the 3rd layer, then enters from the 47th slot of the 4th layer, exits from the 38th slot of the 3rd layer, then enters from the 29th slot of the 4th layer, exits from the 20th slot of the 3rd layer, and thus the traversal of the flat wires of the 3rd and 4th layers is completed.

[0182] The third sub-branch of the first branch of the U-phase starts from the 11th slot of the 2nd layer, enters from the 11th slot of the 2nd layer, and exits from the 1st slot of the 1st layer, then enters from the 46th slot of the 2nd layer, exits from the 37th slot of the 1st layer, then enters from the 28th slot of the 2nd layer, exits from the 19th slot of the 1st layer, then enters from the 10th slot of the 2nd layer, exits from the 54th slot of the 1st layer, then enters from the 45th slot of the 2nd layer, exits from the 36th slot of the 1st layer, then enters from the 27th slot of the 2nd layer, exits from the 18th slot of the 1st layer, then enters from the 9th slot of the 2nd layer, exits from the 2nd slot of the 1st layer, then enters from the 47th slot of the 2nd layer, exits from the 38th slot of the 1st layer, then enters from the 29th slot of the 2nd layer, exits from the 20th slot of the 1st layer, and thus the traversal of the flat wires of the 1st and 2nd layers is completed.

[0183] The first end of the fourth sub-branch of the second branch of the U phase starts from the 12th slot of the second layer, enters from the 12th slot of the second layer, exits from the 2nd slot of the first layer, then enters from the 47th slot of the second layer, exits from the 38th slot of the first layer, then enters from the 29th slot of the second layer, exits from the 20th slot of the first layer, then enters from the 11th slot of the second layer, exits from the 1st slot of the first layer, then enters from the 46th slot of the second layer, exits from the 37th slot of the first layer, then enters from the 28th slot of the second layer, exits from the 19th slot of the first layer, then enters from the 10th slot of the second layer, exits from the 3rd slot of the first layer, then enters from the 48th slot of the second layer, exits from the 39th slot of the first layer, then enters from the 30th slot of the second layer, exits from the 21st slot of the first layer, thus completing the traversal of the flat wires of the first layer and the second layer.

[0184] Thus, the outgoing end of the second branch of the U phase winding is formed by leading out from the 21st slot of the first layer. 2out .

[0185] The connection mode of the first branch of the V phase and the first branch of the W phase can be obtained by translating the connection mode of the first branch of the U phase in FIG. 5. The connection mode of the second branch of the V phase and the second branch of the W phase can be obtained by translating the connection mode of the second branch of the U phase in FIG. 5.

[0186] FIG. 13 is a structural schematic diagram of a welded end of a motor stator in the embodiment one of the application, and FIG. 14 is a structural schematic diagram of a crown end of the motor stator in the embodiment one of the application.

[0187] As shown in FIGS. 13 and 14, the winding arrangement in the embodiment one of the application is regular, the outgoing wires of each phase are all at the welded end and are all at the first layer or the Lth layer, thus simplifying the busbar structure design.

[0188] Table 1. Comparison table of harmonic winding coefficients of each order of the embodiment one, the conventional full-pitch winding and the conventional short-pitch winding

[0189] As shown in Table 1, the harmonic number 1 represents the fundamental wave, the 5th and 7th order harmonic winding coefficients of the conventional short-pitch winding with a pitch of 8 are 0.1399 and 0.0607 respectively, and the 11th and 13th order harmonic winding coefficients are 0.0607 and 0.1399 respectively, while the 5th, 7th, 11th and 13th order harmonic winding coefficients of the continuous short-pitch winding in the embodiment one of the application shown in FIG. 5 are 0.0899, 0.0207, 0.0207 and 0.0899 respectively. The 5th, 7th, 11th and 13th order harmonic winding coefficients in the embodiment one of the application shown in FIG. 5 are much lower than those of the conventional short-pitch winding with a pitch of 8, the weakening effect on the 5th, 7th, 11th and 13th order harmonics of the armature side magnetic field is stronger, and the fundamental wave coefficient is 0.9209, which is not much lower than 0.9598 of the full-pitch winding, and is relatively close.

[0190] As shown in Table 1, the 7th and 11th harmonic winding factor of the continuous short-pitch winding in the embodiment one shown in Fig. 5 is 0.0207, and the 7th and 11th harmonic winding factor of the traditional short-pitch winding with a pitch of 7 is 0.1359. The 7th and 11th harmonic winding factor of the continuous short-pitch winding in the embodiment one shown in Fig. 5 is much lower than that of the traditional short-pitch winding with a pitch of 7. Although the 5th and 13th harmonic winding factor of the continuous short-pitch winding in the embodiment one shown in Fig. 5 is 0.0899, which is slightly higher than 0.0378 of the traditional short-pitch winding with a pitch of 7, the fundamental winding factor of the continuous short-pitch winding in the embodiment one shown in Fig. 5 is 0.9019, which is higher than 0.9019 of the traditional short-pitch winding with a pitch of 7. The continuous short-pitch winding in the embodiment one shown in Fig. 5 reduces the influence of short-pitch on average torque and has the advantage of weakening high-order harmonics without weakening the fundamental.

[0191] Fig. 15 is a comparison diagram of torque pulsation of winding peak working points in the embodiment one of the present application. The horizontal coordinate represents electrical angle, and the vertical coordinate represents torque.

[0192] As shown in Fig. 15, curve A represents the torque waveform of the continuous short-pitch winding in the embodiment one shown in Fig. 5, curve B represents the torque waveform of the traditional short-pitch winding, and curve C represents the torque waveform of the full-pitch winding. The peak torque value of the full-pitch winding can reach 430 Nm, and the trough value can be close to 413 Nm, and the torque pulsation is large. The torque pulsation of the working points of the continuous short-pitch winding in the embodiment one shown in Fig. 5 and the traditional short-pitch winding is between 413 Nm and 425 Nm. The torque pulsation of the peak torque working point of the continuous short-pitch winding in the embodiment one shown in Fig. 5 is smaller than that of the traditional full-pitch winding and the traditional short-pitch winding.

[0193] In an embodiment, the winding slot of the stator core is Z=54, the number of stator winding magnetic poles and the number of rotor poles is 2p=6, the number of slots per pole per phase q=Z / (2mp)=3, the number of layers L=8 of the flat wire layer in the winding slot, and the stator winding is divided into U phase, V phase and W phase. Each phase winding is provided with two parallel branches. Fig. 6 is a connection diagram of two parallel branches of the U phase in the embodiment.

[0194] As shown in Fig. 6 and Fig. 3, each winding slot contains L=8 layers of flat wires, the first layer is denoted as L1, the second layer is denoted as L2, the third layer is denoted as L3, the fourth layer is denoted as L4, the fifth layer is denoted as L5, the sixth layer is denoted as L6, the seventh layer is denoted as L7, and the eighth layer is denoted as L8. The first layer is the slot bottom layer of the winding slot, and the eighth layer is the slot opening layer.

[0195] Each parallel branch in Fig. 6 traverses the position of the flat wire layer that can be arranged, so the number of each parallel branch can keep the potential balance and will not produce circulating current. The 8 layers of flat wire are divided into 3 groups, T1, T2, T3 take 2, 4, 2 respectively, that is, T1 contains the first 1 / 2 layer of flat wire, T2 contains the 3rd / 4th / 5th / 6th layer of flat wire, and T3 contains the 7th / 8th layer of flat wire. The flat wire of T2 layer is staggered by 1 winding slot in the clockwise direction of the flat wire motor relative to the flat wire of T1 layer, and the flat wire of T3 layer is staggered by 1 winding slot in the same direction relative to the flat wire of T2 layer, so that the winding realizes the effect of continuous short distance.

[0196] The flat wires belonging to the same parallel branch are connected in sequence between each group to form the sub-branch of the branch.

[0197] For example, the first sub-branch of the first branch of U phase starts from the first layer of the 10th slot, connects all flat wires belonging to the first branch of the first / second layer, and then the tail end lead-out wire is led out from the second layer of the 19th slot. During this process, hairpin coils of three spans are used, and the spans are Z / 2p-q+1=7, Z / 2p=9, and Z / 2p+1=10 respectively.

[0198] The first sub-branch of the first branch of U phase starts from the first layer of the 10th slot, connects all flat wires belonging to the first / second layer, and then the tail end lead-out wire is led out from the second layer of the 19th slot. During this process, hairpin coils of three spans are used, and the spans are Z / 2p-q+1=7, Z / 2p=9, and Z / 2p+1=10 respectively.

[0199] The first sub-branch of the first branch of U phase starts from the first layer of the 10th slot, connects all flat wires belonging to the first / second layer, and then the tail end lead-out wire is led out from the second layer of the 19th slot. During this process, hairpin coils of three spans are used, and the spans are Z / 2p-q+1=7, Z / 2p=9, and Z / 2p+1=10 respectively.

[0200] The first sub-branch of the first branch of U phase starts from the first layer of the 10th slot, connects all flat wires belonging to the first / second layer, and then the tail end lead-out wire is led out from the second layer of the 19th slot. During this process, hairpin coils of three spans are used, and the spans are Z / 2p-q+1=7, Z / 2p=9, and Z / 2p+1=10 respectively.

[0201] From the four sub-branches of the first branch, it can be known that the total number of hairpin coils is 3*L / 2=12.

[0202] The first, second, third, and fourth sub-branches of the second branch of U phase can be arranged by referring to the first branch of U phase, and details are not repeated here.

[0203] The single cross-layer cross-wire segment is used to realize cross-layer, connect the first, second, third and fourth sub-branch coils, and the cross-layer cross-wire segments between layers can be equal or not equal. In the embodiment two shown in FIG. 6 of the present application, the cross-layer cross-wire segments of the second layer crossing the third layer, the fourth layer crossing the fifth layer and the sixth layer crossing the seventh layer have a cross-layer cross-wire segment distance of Z / 2p = 9. The welding end cross-layer cross-wire segments of each sub-branch are equal, and in the embodiment two shown in FIG. 6 of the present application, the welding end cross-layer cross-wire segments are all Z / 2p = 9, which simplifies the process of twisting, welding and coating.

[0204] As shown in FIG. 6, the T1 layer flat wire, the T2 layer flat wire and the T3 layer flat wire respectively include different phase belts, which are not described in detail here.

[0205] As shown in FIG. 6, the solid line represents the connection mode of the crown end of the hairpin coil or the cross-wire segment, and the dashed line represents the connection mode of the welding end of the hairpin coil or the welding segment.

[0206] The connection mode of the U-phase two parallel branches in the embodiment of the present application will be described in detail below with reference to FIG. 6. The connection mode of the crown end of the stator winding will be described below according to the solid line connection mode in FIG. 5, and the connection mode of the welding end of the stator winding can be referred to the dashed line connection mode.

[0207] As shown in FIG. 6, the first sub-branch of the first branch of the U-phase has a first end outgoing line starting from the first layer of the tenth slot as an incoming end U 1in From the first layer of the tenth slot, from the second layer of the third slot, then from the first layer of the forty-eighth slot, from the second layer of the thirty-ninth slot, then from the first layer of the thirtieth slot, from the second layer of the twenty-first slot, then from the first layer of the twelfth slot, from the second layer of the second slot, then from the first layer of the forty-seventh slot, from the second layer of the thirty-eighth slot, then from the first layer of the twenty-ninth slot, from the second layer of the twentieth slot, then from the first layer of the eleventh slot, from the second layer of the first slot, then from the first layer of the forty-sixth slot, from the second layer of the thirty-seventh slot, then from the first layer of the twenty-eighth slot, from the second layer of the nineteenth slot, thus completing the traversal of the first layer and the second layer flat wires.

[0208] The first sub-branch of the first branch of the U-phase starts from the 3rd layer of the 10th slot, enters from the 3rd layer of the 10th slot, exits from the 4th layer of the 54th slot, then enters from the 3rd layer of the 45th slot, exits from the 4th layer of the 36th slot, then enters from the 3rd layer of the 27th slot, exits from the 4th layer of the 18th slot, then enters from the 3rd layer of the 9th slot, exits from the 4th layer of the 2nd slot, then enters from the 3rd layer of the 47th slot, exits from the 4th layer of the 38th slot, then enters from the 3rd layer of the 29th slot, exits from the 4th layer of the 20th slot, then enters from the 3rd layer of the 11th slot, exits from the 4th layer of the 1st slot, then enters from the 3rd layer of the 46th slot, exits from the 4th layer of the 37th slot, then enters from the 3rd layer of the 28th slot, exits from the 4th layer of the 19th slot, thus completing the traversal of the flat wires of the 3rd layer and the 4th layer.

[0209] The third sub-branch of the first branch of the U-phase starts from the 5th layer of the 10th slot, enters from the 5th layer of the 10th slot, exits from the 6th layer of the 54th slot, then enters from the 5th layer of the 45th slot, exits from the 6th layer of the 36th slot, then enters from the 5th layer of the 27th slot, exits from the 6th layer of the 18th slot, then enters from the 5th layer of the 9th slot, exits from the 6th layer of the 2nd slot, then enters from the 5th layer of the 47th slot, exits from the 6th layer of the 38th slot, then enters from the 5th layer of the 29th slot, exits from the 6th layer of the 20th slot, then enters from the 5th layer of the 11th slot, exits from the 6th layer of the 1st slot, then enters from the 5th layer of the 46th slot, exits from the 6th layer of the 37th slot, then enters from the 5th layer of the 28th slot, exits from the 6th layer of the 19th slot, thus completing the traversal of the flat wires of the 5th layer and the 6th layer.

[0210] The fourth sub-branch of the first branch of the U-phase starts from the 7th layer of the 10th slot, enters from the 7th layer of the 10th slot, exits from the 8th layer of the 54th slot, then enters from the 7th layer of the 45th slot, exits from the 8th layer of the 36th slot, then enters from the 7th layer of the 27th slot, exits from the 8th layer of the 18th slot, then enters from the 7th layer of the 9th slot, exits from the 8th layer of the 53rd slot, then enters from the 7th layer of the 44th slot, exits from the 8th layer of the 35th slot, then enters from the 7th layer of the 26th slot, exits from the 8th layer of the 17th slot, then enters from the 7th layer of the 8th slot, exits from the 8th layer of the 1st slot, then enters from the 7th layer of the 46th slot, exits from the 8th layer of the 37th slot, then enters from the 7th layer of the 28th slot, exits from the 8th layer of the 19th slot, thus completing the traversal of the flat wires of the 7th layer and the 8th layer.

[0211] Thus, the outgoing line from the 8th layer of the 1st slot is formed, which is the outgoing end U 1out .

[0212] As shown in FIG. 6, the first sub-branch of the second branch of the U-phase starts from the 8th layer of the 10th slot as the incoming end U 2inThe first sub-branch of the first branch of the U-phase starts from the 10th slot of the 6th layer, enters from the 10th slot of the 6th layer, exits from the 19th slot of the 5th layer, then enters from the 28th slot of the 6th layer, exits from the 37th slot of the 5th layer, then enters from the 46th slot of the 6th layer, exits from the 2nd slot of the 5th layer, then enters from the 11th slot of the 6th layer, exits from the 20th slot of the 5th layer, then enters from the 29th slot of the 6th layer, exits from the 38th slot of the 5th layer, then enters from the 47th slot of the 6th layer, exits from the 54th slot of the 5th layer, then enters from the 9th slot of the 6th layer, exits from the 18th slot of the 5th layer, then enters from the 27th slot of the 6th layer, exits from the 36th slot of the 5th layer, then enters from the 45th slot of the 6th layer, exits from the 1st slot of the 5th layer, and thus the traversal of the flat wires of the 5th and 6th layers is completed.

[0213] The first sub-branch of the first branch of the U-phase starts from the 10th slot of the 6th layer, enters from the 10th slot of the 6th layer, exits from the 19th slot of the 5th layer, then enters from the 28th slot of the 6th layer, exits from the 37th slot of the 5th layer, then enters from the 46th slot of the 6th layer, exits from the 2nd slot of the 5th layer, then enters from the 11th slot of the 6th layer, exits from the 20th slot of the 5th layer, then enters from the 29th slot of the 6th layer, exits from the 38th slot of the 5th layer, then enters from the 47th slot of the 6th layer, exits from the 54th slot of the 5th layer, then enters from the 9th slot of the 6th layer, exits from the 18th slot of the 5th layer, then enters from the 27th slot of the 6th layer, exits from the 36th slot of the 5th layer, then enters from the 45th slot of the 6th layer, exits from the 1st slot of the 5th layer, and thus the traversal of the flat wires of the 5th and 6th layers is completed.

[0214] The first sub-branch of the first branch of the U-phase starts from the 10th slot of the 6th layer, enters from the 10th slot of the 6th layer, exits from the 19th slot of the 5th layer, then enters from the 28th slot of the 6th layer, exits from the 37th slot of the 5th layer, then enters from the 46th slot of the 6th layer, exits from the 2nd slot of the 5th layer, then enters from the 11th slot of the 6th layer, exits from the 20th slot of the 5th layer, then enters from the 29th slot of the 6th layer, exits from the 38th slot of the 5th layer, then enters from the 47th slot of the 6th layer, exits from the 54th slot of the 5th layer, then enters from the 9th slot of the 6th layer, exits from the 18th slot of the 5th layer, then enters from the 27th slot of the 6th layer, exits from the 36th slot of the 5th layer, then enters from the 45th slot of the 6th layer, exits from the 1st slot of the 5th layer, and thus the traversal of the flat wires of the 5th and 6th layers is completed.

[0215] The first end of the fourth sub-branch of the second branch of the U phase is led out from the 2nd layer of the 10th slot, enters from the 2nd layer of the 10th slot, exits from the 1st layer of the 19th slot, then enters from the 2nd layer of the 28th slot, exits from the 1st layer of the 37th slot, then enters from the 2nd layer of the 46th slot, exits from the 1st layer of the 2nd slot, then enters from the 2nd layer of the 11th slot, exits from the 1st layer of the 20th slot, then enters from the 2nd layer of the 29th slot, exits from the 1st layer of the 38th slot, then enters from the 2nd layer of the 47th slot, exits from the 1st layer of the 3rd slot, then enters from the 2nd layer of the 12th slot, exits from the 1st layer of the 21st slot, then enters from the 2nd layer of the 30th slot, exits from the 1st layer of the 39th slot, then enters from the 2nd layer of the 48th slot, exits from the 1st layer of the 1st slot, thus completing the traversal of the flat wires in the 1st layer and the 2nd layer.

[0216] Thus, the wires are led out from the 1st layer of the 1st slot, forming the outgoing end U 2out .

[0217] The connection mode of the first branch of the V phase and the first branch of the W phase can be obtained by translating the connection mode of the first branch of the U phase in FIG. 6. The connection mode of the second branch of the V phase and the second branch of the W phase can be obtained by translating the connection mode of the second branch of the U phase in FIG. 6.

[0218] In an embodiment, the winding slots of the stator core are Z=54, the number of magnetic poles of the stator winding and the number of rotor poles are 2p=6, the number of slots per pole per phase q=Z / (2mp)=3, the number of layers of the flat wire in the winding slot is L=8, the stator winding is divided into a U phase, a V phase and a W phase, and the number of parallel branches of each phase winding is 2. FIG. 7 is a schematic diagram of the connection of the two parallel branches of the U phase in the embodiment.

[0219] As shown in FIG. 7 and FIG. 3, each winding slot contains L=8 layers of flat wires, the 1st layer is denoted as L1, the 2nd layer is denoted as L2, the 3rd layer is denoted as L3, the 4th layer is denoted as L4, the 5th layer is denoted as L5, the 6th layer is denoted as L6, the 7th layer is denoted as L7, and the 8th layer is denoted as L8. The 1st layer is the slot bottom layer, and the 8th layer is the slot opening layer.

[0220] Each parallel branch in FIG. 7 traverses the position of the flat wire that can be arranged, so that the number of each parallel branch can maintain potential balance and will not produce circulating current. The 8 layers of flat wires are divided into 3 groups, T1, T2 and T3, which are 3, 2 and 3 respectively, that is, T1 contains the 1st / 2nd / 3rd layer of flat wires, T2 contains the 4th / 5th layer of flat wires, and T3 contains the 6th / 7th / 8th layer of flat wires. The flat wires in the T2 layer are staggered by 1 winding slot in the clockwise direction of the flat wire motor relative to the flat wires in the T1 layer, and the flat wires in the T3 layer are staggered by 1 winding slot in the same direction relative to the flat wires in the T2 layer, so that the winding realizes the effect of continuous short distance.

[0221] The flat wires belonging to the same parallel branch are connected in sequence between each group to form a sub-branch of the branch.

[0222] For example, the first sub-branch of the U-phase first branch has a first end lead-out wire starting from the 1st layer of the 10th slot, and after connecting all the flat wires belonging to the first branch on the 1st / 2nd layers, a tail end lead-out wire is led out from the 2nd layer of the 19th slot, in which three kinds of hairpin coils with spans of Z / 2p-q+1=7, Z / 2p=9 and Z / 2p+1=10 are used.

[0223] The first sub-branch of the U-phase second branch has a first end lead-out wire starting from the 3rd layer of the 10th slot, and after connecting all the flat wires belonging to the first branch on the 3rd / 4th layers, a tail end lead-out wire is led out from the 4th layer of the 18th slot, in which three kinds of hairpin coils with spans of Z / 2p-q+2=8, Z / 2p+1=10 and Z / 2p+2=11 are used.

[0224] The first sub-branch of the U-phase third branch has a first end lead-out wire starting from the 5th layer of the 9th slot, and after connecting all the flat wires belonging to the first branch on the 5th / 6th layers, a tail end lead-out wire is led out from the 6th layer of the 17th slot, in which three kinds of hairpin coils with spans of Z / 2p-q+2=8, Z / 2p+1=10 and Z / 2p+2=11 are used.

[0225] The first sub-branch of the U-phase fourth branch has a first end lead-out wire starting from the 7th layer of the 8th slot, and after connecting all the flat wires belonging to the first branch on the 7th / 8th layers, a tail end lead-out wire is led out from the 8th layer of the 17th slot, in which three kinds of hairpin coils with spans of Z / 2p-q+1=7, Z / 2p=9 and Z / 2p+1=10 are used.

[0226] As can be seen from the four sub-branches of the first branch, the total number of hairpin coils is 3*L / 2=12.

[0227] The first, second, third and fourth sub-branches of the U-phase second branch can be arranged by referring to the U-phase first branch, and will not be described here.

[0228] The single layer-crossing wire segment is used to realize layer crossing and connect the first, second, third and fourth sub-branch coils. In the embodiment three shown in FIG. 7, the layer-crossing wire segments between the layers have equal spans, and the span is Z / 2p=9. Except for the layer-crossing wire segments, the remaining welding layers contain two kinds of spans, which are Z / 2p-1=8 and Z / 2p=9.

[0229] As shown in FIG. 7, the T1 layer flat wire, the T2 layer flat wire and the T3 layer flat wire respectively include different phase belts, each phase belt includes three winding slots arranged adjacently, the phase belt of the T2 layer flat wire is staggered by one winding slot relative to the phase belt of the T1 layer flat wire, and the phase belt of the T3 layer flat wire is staggered by one winding slot relative to the phase belt of the T2 layer flat wire. For example, in the T1 layer flat wire, the 1st / 2nd / 3rd layer flat wire in the 10th / 11th / 12th slot is a phase belt, in the T2 layer flat wire, the 4th / 5th layer flat wire in the 9th / 10th / 11th slot is a phase belt, and in the T3 layer flat wire, the 6th / 7th / 8th layer flat wire in the 8th / 9th / 10th slot is a phase belt.

[0230] As shown in FIG. 7, the solid line represents the connection mode of the crown end or the cross wire segment of the hairpin coil, and the dashed line represents the connection mode of the welding end or the welding segment of the hairpin coil.

[0231] The connection mode of the U phase two parallel branches in the embodiment of the application will be described in detail below in combination with FIG. 7. The connection mode of the stator winding at the crown end will be described below according to the solid line connection mode in FIG. 7, and the connection mode of the welding end of the stator winding can be referred to the dashed line connection mode.

[0232] As shown in FIG. 7, the first sub-branch of the U phase first branch is started from the 1st layer of the 10th slot as the incoming end U 1in from the 1st layer of the 10th slot, from the 2nd layer of the 3rd slot, then from the 1st layer of the 48th slot, from the 2nd layer of the 39th slot, then from the 1st layer of the 30th slot, from the 2nd layer of the 21st slot, then from the 1st layer of the 12th slot, from the 2nd layer of the 2nd slot, then from the 1st layer of the 47th slot, from the 2nd layer of the 38th slot, then from the 1st layer of the 29th slot, from the 2nd layer of the 20th slot, then from the 1st layer of the 11th slot, from the 2nd layer of the 1st slot, then from the 1st layer of the 46th slot, from the 2nd layer of the 37th slot, then from the 1st layer of the 28th slot, from the 2nd layer of the 19th slot, thus completing the traversal of the 1st layer and the 2nd layer flat wire.

[0233] The first sub-branch of the U phase first branch is started from the 3rd layer of the 10th slot, from the 3rd layer of the 10th slot, from the 4th layer of the 2nd slot, then from the 3rd layer of the 48th slot, from the 4th layer of the 38th slot, then from the 3rd layer of the 30th slot, from the 4th layer of the 20th slot, then from the 3rd layer of the 12th slot, from the 4th layer of the 1st slot, then from the 3rd layer of the 47th slot, from the 4th layer of the 37th slot, then from the 3rd layer of the 29th slot, from the 4th layer of the 19th slot, then from the 3rd layer of the 11th slot, from the 4th layer of the 54th slot, then from the 3rd layer of the 46th slot, from the 4th layer of the 36th slot, then from the 3rd layer of the 28th slot, from the 4th layer of the 18th slot, thus completing the traversal of the 3rd layer and the 4th layer flat wire.

[0234] The first end of the third sub-branch of the first branch of the U-phase starts from the 9th slot of the 5th layer, enters from the 9th slot of the 5th layer, exits from the 1st slot of the 6th layer, then enters from the 47th slot of the 5th layer, exits from the 37th slot of the 6th layer, then enters from the 29th slot of the 5th layer, exits from the 19th slot of the 6th layer, then enters from the 11th slot of the 5th layer, exits from the 54th slot of the 6th layer, then enters from the 46th slot of the 5th layer, exits from the 36th slot of the 6th layer, then enters from the 28th slot of the 5th layer, exits from the 18th slot of the 6th layer, then enters from the 10th slot of the 5th layer, exits from the 53rd slot of the 6th layer, then enters from the 45th slot of the 5th layer, exits from the 35th slot of the 6th layer, then enters from the 27th slot of the 5th layer, exits from the 17th slot of the 6th layer, thus completing the traversal of the flat wires of the 5th layer and the 6th layer.

[0235] The first end of the fourth sub-branch of the first branch of the U-phase starts from the 8th slot of the 7th layer, enters from the 8th slot of the 7th layer, exits from the 1st slot of the 8th layer, then enters from the 46th slot of the 7th layer, exits from the 37th slot of the 8th layer, then enters from the 28th slot of the 7th layer, exits from the 19th slot of the 8th layer, then enters from the 10th slot of the 7th layer, exits from the 54th slot of the 8th layer, then enters from the 45th slot of the 7th layer, exits from the 36th slot of the 8th layer, then enters from the 27th slot of the 7th layer, exits from the 18th slot of the 8th layer, then enters from the 9th slot of the 7th layer, exits from the 53rd slot of the 8th layer, then enters from the 44th slot of the 7th layer, exits from the 35th slot of the 8th layer, then enters from the 26th slot of the 7th layer, exits from the 17th slot of the 8th layer, thus completing the traversal of the flat wires of the 7th layer and the 8th layer.

[0236] Thus, the outgoing line end U 1out .

[0237] The first end of the first sub-branch of the second branch of the U-phase starts from the 10th slot of the 8th layer as the incoming line end U 2in , enters from the 10th slot of the 8th layer, exits from the 19th slot of the 7th layer, then enters from the 28th slot of the 8th layer, exits from the 37th slot of the 7th layer, then enters from the 46th slot of the 8th layer, exits from the 53rd slot of the 7th layer, then enters from the 8th slot of the 8th layer, exits from the 17th slot of the 7th layer, then enters from the 26th slot of the 8th layer, exits from the 35th slot of the 7th layer, then enters from the 44th slot of the 8th layer, exits from the 54th slot of the 7th layer, then enters from the 9th slot of the 8th layer, exits from the 18th slot of the 7th layer, then enters from the 27th slot of the 8th layer, exits from the 36th slot of the 7th layer, then enters from the 45th slot of the 8th layer, exits from the 1st slot of the 7th layer, thus completing the traversal of the flat wires of the 7th layer and the 8th layer.

[0238] The first sub-branch of the second branch of the U-phase starts from the 10th slot of the 6th layer, enters from the 10th slot of the 6th layer, exits from the 20th slot of the 5th layer, then enters from the 28th slot of the 6th layer, exits from the 38th slot of the 5th layer, then enters from the 46th slot of the 6th layer, exits from the 54th slot of the 5th layer, then enters from the 8th slot of the 6th layer, exits from the 18th slot of the 5th layer, then enters from the 26th slot of the 6th layer, exits from the 36th slot of the 5th layer, then enters from the 44th slot of the 6th layer, exits from the 1st slot of the 5th layer, then enters from the 9th slot of the 6th layer, exits from the 19th slot of the 5th layer, then enters from the 27th slot of the 6th layer, exits from the 37th slot of the 5th layer, then enters from the 45th slot of the 6th layer, exits from the 2nd slot of the 5th layer, and thus completes the traversal of the flat wires of the 5th layer and the 6th layer.

[0239] The third sub-branch of the second branch of the U-phase starts from the 11th slot of the 4th layer, enters from the 11th slot of the 4th layer, exits from the 21st slot of the 3rd layer, then enters from the 29th slot of the 4th layer, exits from the 39th slot of the 3rd layer, then enters from the 47th slot of the 4th layer, exits from the 1st slot of the 3rd layer, then enters from the 9th slot of the 4th layer, exits from the 19th slot of the 3rd layer, then enters from the 27th slot of the 4th layer, exits from the 37th slot of the 3rd layer, then enters from the 45th slot of the 4th layer, exits from the 2nd slot of the 3rd layer, then enters from the 10th slot of the 4th layer, exits from the 20th slot of the 3rd layer, then enters from the 28th slot of the 4th layer, exits from the 38th slot of the 3rd layer, then enters from the 46th slot of the 4th layer, exits from the 3rd slot of the 3rd layer, and thus completes the traversal of the flat wires of the 3rd layer and the 4th layer.

[0240] The fourth sub-branch of the second branch of the U-phase starts from the 12th slot of the 2nd layer, enters from the 12th slot of the 2nd layer, exits from the 21st slot of the 1st layer, then enters from the 30th slot of the 2nd layer, exits from the 39th slot of the 1st layer, then enters from the 48th slot of the 2nd layer, exits from the 1st slot of the 1st layer, then enters from the 10th slot of the 2nd layer, exits from the 19th slot of the 1st layer, then enters from the 28th slot of the 2nd layer, exits from the 37th slot of the 1st layer, then enters from the 46th slot of the 2nd layer, exits from the 2nd slot of the 1st layer, then enters from the 11th slot of the 2nd layer, exits from the 20th slot of the 1st layer, then enters from the 29th slot of the 2nd layer, exits from the 38th slot of the 1st layer, then enters from the 47th slot of the 2nd layer, exits from the 3rd slot of the 1st layer, and thus completes the traversal of the flat wires of the 1st layer and the 2nd layer.

[0241] Thus, the outgoing line end U of the second branch of the U-phase winding is formed by leading out from the 3rd slot of the 1st layer. 2out .

[0242] The connection mode of the first branch of the V phase and the first branch of the W phase can be obtained by translating the first branch of the U phase in Fig. 7. The connection mode of the second branch of the V phase and the second branch of the W phase can be obtained by translating the second branch of the U phase in Fig. 7.

[0243] In an embodiment, the winding slot of the stator core is Z=54, the number of stator winding magnetic poles and the number of rotor poles is 2p=6, the number of slots per pole per phase is q=Z / (2mp)=3, the number of layers of the flat wire layer in the winding slot is L=4, the stator winding is divided into U phase, V phase and W phase, and the number of parallel branches of each phase winding is 2.

[0244] As shown in Fig. 8 and Fig. 3, each winding slot contains L=4 layers of flat wires, the first layer is L1, the second layer is L2, the third layer is L3, and the fourth layer is L4. The first layer is the slot bottom layer, and the fourth layer is the slot opening layer.

[0245] Each parallel branch in Fig. 8 traverses the position of the flat wire layer that can be arranged, so that the number of parallel branches can maintain potential balance and will not produce circulating current. The 4 layers of flat wires are divided into 3 groups, T1, T2 and T3, which are 1, 2 and 1 respectively, that is, T1 contains the first layer of flat wires, T2 contains the second / third layer of flat wires, and T3 contains the fourth layer of flat wires. The flat wires of the T2 layer are staggered by one winding slot in the clockwise direction of the flat motor relative to the flat wires of the T1 layer, and the flat wires of the T3 layer are staggered by one winding slot in the same direction relative to the flat wires of the T2 layer, so that the winding realizes the effect of continuous short distance.

[0246] For example, the first sub-branch of the first branch of the U phase starts from the first layer of the 10th slot, connects all the flat wires belonging to the first branch of the first / second layer, and then the tail end lead-out wire is led out from the second layer of the 18th slot. During this process, three kinds of hairpin coils with spans of Z / 2p-q+2=8, Z / 2p+1=10 and Z / 2p+2=11 are used.

[0247] The first sub-branch of the first branch of the U phase starts from the first layer of the 10th slot, connects all the flat wires belonging to the first / second layer, and then the tail end lead-out wire is led out from the second layer of the 18th slot. During this process, three kinds of hairpin coils with spans of Z / 2p-q+2=8, Z / 2p+1=10 and Z / 2p+2=11 are used.

[0248] As can be seen from the two sub-branches, the total number of hairpin coils is 3*L / 2=6.

[0249] The first and second sub-branches of the second branch of the U phase can be arranged by referring to the first branch of the U phase, and will not be described here.

[0250] The single cross-layer cross-wire segment is used to realize cross-layer and connect the first and second sub-branch coils. In the embodiment four shown in Fig. 8, the cross-layer cross-wire segments between layers have equal cross-layer distances, and the cross-layer distance is Z / 2p+1=10. Except the cross-layer cross-wire segments, the remaining welding layers only contain one cross-layer distance, and the cross-layer distance is Z / 2p-1=8. The twisting, welding and coating processes can be simplified.

[0251] As shown in Fig. 8, the T1 layer flat wire, the T2 layer flat wire and the T3 layer flat wire respectively include different phase belts, each phase belt includes three winding slots arranged adjacently, the phase belt of the T2 layer flat wire is staggered by one winding slot relative to the phase belt of the T1 layer flat wire, and the phase belt of the T3 layer flat wire is staggered by one winding slot relative to the phase belt of the T2 layer flat wire. For example, in the T1 layer flat wire, the first layer flat wire in the 10th slot, the 11th slot and the 12th slot is a phase belt, in the T2 layer flat wire, the 2 / 3 layer flat wire in the 9th slot, the 10th slot and the 11th slot is a phase belt, and in the T3 layer flat wire, the 4th layer flat wire in the 8th slot, the 9th slot and the 10th slot is a phase belt.

[0252] As shown in Fig. 8, the solid line represents the connection mode of the crown end of the hairpin coil or the cross-wire segment, and the dotted line represents the connection mode of the welding end of the hairpin coil or the welding segment.

[0253] The connection mode of the U phase two parallel branches in the embodiment of the application will be described in detail below with reference to Fig. 8. The connection mode of the stator winding at the crown end will be described below according to the solid line connection mode in Fig. 8, and the connection mode of the welding end of the stator winding can be referred to the dotted line connection mode.

[0254] As shown in Fig. 8, the first sub-branch of the U phase first branch is connected to the first layer of the 10th slot as the incoming end U 1in From the first layer of the 10th slot, the second layer of the 2nd slot, then the first layer of the 48th slot, the second layer of the 38th slot, then the first layer of the 30th slot, the second layer of the 20th slot, then the first layer of the 12th slot, the second layer of the 1st slot, then the first layer of the 47th slot, the second layer of the 37th slot, then the first layer of the 29th slot, the second layer of the 19th slot, then the first layer of the 11th slot, the second layer of the 54th slot, then the first layer of the 46th slot, the second layer of the 36th slot, then the first layer of the 28th slot, the second layer of the 18th slot, and thus the traversal of the first layer and the second layer flat wires is completed.

[0255] The first sub-branch of the first branch of the U-phase winding starts from the third layer of the tenth slot, enters from the third layer of the tenth slot, exits from the fourth layer of the fifty-third slot, then enters from the third layer of the forty-fifth slot, exits from the fourth layer of the thirty-fifth slot, then enters from the third layer of the twenty-seventh slot, exits from the fourth layer of the seventeenth slot, then enters from the third layer of the ninth slot, exits from the fourth layer of the first slot, then enters from the third layer of the forty-seventh slot, exits from the fourth layer of the thirty-seventh slot, then enters from the third layer of the twenty-ninth slot, exits from the fourth layer of the nineteenth slot, then enters from the third layer of the eleventh slot, exits from the fourth layer of the fifty-fourth slot, then enters from the third layer of the forty-sixth slot, exits from the fourth layer of the thirty-sixth slot, then enters from the third layer of the twenty-eighth slot, exits from the fourth layer of the eighteenth slot, and thus completes the traversal of the third layer and the fourth layer of the flat wire.

[0256] Thus, the outgoing line end U of the first branch of the U-phase winding is formed by leading out from the fourth layer of the eighteenth slot. 1out .

[0257] The first sub-branch of the second branch of the U-phase winding starts from the fourth layer of the tenth slot as the incoming line end U 2in , enters from the fourth layer of the tenth slot, exits from the third layer of the twentieth slot, then enters from the fourth layer of the twenty-eighth slot, exits from the third layer of the thirty-eighth slot, then enters from the fourth layer of the forty-sixth slot, exits from the third layer of the fifty-fourth slot, then enters from the fourth layer of the eighth slot, exits from the third layer of the eighteenth slot, then enters from the fourth layer of the twenty-sixth slot, exits from the third layer of the thirty-sixth slot, then enters from the fourth layer of the forty-fourth slot, exits from the third layer of the first slot, then enters from the fourth layer of the ninth slot, exits from the third layer of the nineteenth slot, then enters from the fourth layer of the twenty-seventh slot, exits from the third layer of the thirty-seventh slot, then enters from the fourth layer of the forty-fifth slot, exits from the third layer of the second slot, and thus completes the traversal of the third layer and the fourth layer of the flat wire.

[0258] The second sub-branch of the second branch of the U-phase winding starts from the second layer of the tenth slot, enters from the second layer of the tenth slot, exits from the first layer of the twentieth slot, then enters from the second layer of the twenty-eighth slot, exits from the first layer of the thirty-eighth slot, then enters from the second layer of the forty-sixth slot, exits from the first layer of the third slot, then enters from the second layer of the eleventh slot, exits from the first layer of the twenty-first slot, then enters from the second layer of the twenty-ninth slot, exits from the first layer of the thirty-ninth slot, then enters from the second layer of the forty-seventh slot, exits from the first layer of the first slot, then enters from the second layer of the ninth slot, exits from the first layer of the nineteenth slot, then enters from the second layer of the twenty-seventh slot, exits from the first layer of the thirty-seventh slot, then enters from the second layer of the forty-fifth slot, exits from the first layer of the second slot, and thus completes the traversal of the first layer and the second layer of the flat wire.

[0259] Thus, the outgoing line end U of the second branch of the U-phase winding is formed by leading out from the first layer of the second slot. 2out .

[0260] The connection mode of the first branch of the V phase and the first branch of the W phase can be obtained by translating the first branch of the U phase in Fig. 5. The connection mode of the second branch of the V phase and the second branch of the W phase can be obtained by translating the second branch of the U phase in Fig. 5.

[0261] In one embodiment, the difference between the embodiment five shown in Fig. 9 and the embodiment four shown in Fig. 8 is that, in the embodiment five shown in Fig. 9, the tail end outgoing line of the first branch of the U phase in the embodiment four shown in Fig. 8 is connected with the head end outgoing line of the second branch of the U phase, that is, the flat wire in the fourth layer of the eighteenth slot is connected with the flat wire in the fourth layer of the tenth slot, so that the two parallel branches of the U phase are connected in series to form one branch.

[0262] The two branches of the V phase and the W phase are connected similarly to the two branches of the U phase to form one branch respectively.

[0263] In one embodiment, the winding slot of the stator core is Z=54, the number of stator winding magnetic poles and the number of rotor poles is 2p=6, the number of slots per pole per phase q=Z / (2mp)=3, the number of layers of the flat wire in the winding slot L=10, the stator winding is divided into U phase, V phase and W phase, and the number of parallel branches of each phase winding is 2. Fig. 10 is a connection diagram of the two parallel branches of the U phase in the embodiment.

[0264] As shown in Fig. 10 and Fig. 3, each winding slot contains L=10 layers of flat wires, the first layer is L1, the second layer is L2, the third layer is L3, the fourth layer is L4, the fifth layer is L5, the sixth layer is L6, the seventh layer is L7, the eighth layer is L8, the ninth layer is L9 and the tenth layer is L10. The first layer is the bottom layer of the winding slot, and the tenth layer is the slot opening layer.

[0265] Each parallel branch in Fig. 10 traverses the position of the flat wire that can be arranged, so that the number of each parallel branch can maintain potential balance and will not produce circulating current. The 10 layers of flat wires are divided into three groups, T1, T2 and T3, which are 3, 4 and 3 respectively, that is, T1 contains the first / second / third layers of flat wires, T2 contains the fourth / fifth / sixth / seventh layers of flat wires, and T3 contains the eighth / ninth / tenth layers of flat wires. The flat wires in the T2 layer are staggered by one winding slot in the clockwise direction of the flat motor relative to the flat wires in the T1 layer, and the flat wires in the T3 layer are staggered by one winding slot in the same direction relative to the flat wires in the T2 layer, so that the winding realizes the effect of continuous short distance.

[0266] The flat wires belonging to the same parallel branch are sequentially connected between each group to form a sub-branch of the branch.

[0267] For example, the first sub-branch of the U-phase first branch has a first end lead-out wire starting from the 1st layer of the 10th slot, connecting all flat wires belonging to the first branch in the 1st / 2nd layer, and a tail end lead-out wire leading out from the 2nd layer of the 1st slot. In this process, three kinds of hairpin coils with spans of Z / 2p-q+1=7, Z / 2p=9 and Z / 2p+1=10 are used.

[0268] The first, second, third, fourth and fifth sub-branches of the U-phase second branch can be arranged by referring to the U-phase first branch, and details are not described herein.

[0269] The first, second, third, fourth and fifth sub-branches of the U-phase second branch can be arranged by referring to the U-phase first branch, and details are not described herein.

[0270] The first, second, third, fourth and fifth sub-branches of the U-phase second branch can be arranged by referring to the U-phase first branch, and details are not described herein.

[0271] The first, second, third, fourth and fifth sub-branches of the U-phase second branch can be arranged by referring to the U-phase first branch, and details are not described herein.

[0272] The first, second, third, fourth and fifth sub-branches of the U-phase second branch can be arranged by referring to the U-phase first branch, and details are not described herein.

[0273] The first, second, third, fourth and fifth sub-branches of the U-phase second branch can be arranged by referring to the U-phase first branch, and details are not described herein.

[0274] The first, second, third, fourth and fifth sub-branches of the U-phase second branch can be arranged by referring to the U-phase first branch, and details are not described herein.

[0275] As shown in FIG. 10, the T1 layer flat wire, the T2 layer flat wire and the T3 layer flat wire respectively include different phase belts, each phase belt includes three winding slots arranged adjacently, the phase belt of the T2 layer flat wire is staggered by one winding slot relative to the phase belt of the T1 layer flat wire, and the phase belt of the T3 layer flat wire is staggered by one winding slot relative to the phase belt of the T2 layer flat wire. For example, in the T1 layer flat wire, the 1st / 2nd / 3rd layer flat wire in the 10th slot, the 11th slot and the 12th slot is a phase belt, in the T2 layer flat wire, the 4th / 5th / 6th / 7th layer flat wire in the 9th slot, the 10th slot and the 11th slot is a phase belt, and in the T3 layer flat wire, the 8th / 9th / 10th layer flat wire in the 8th slot, the 9th slot and the 10th slot is a phase belt.

[0276] As shown in FIG. 10, the solid line represents the connection mode of the crown end of the hairpin coil or the cross wire segment, and the dashed line represents the connection mode of the welding end of the hairpin coil or the welding segment.

[0277] The connection mode of the U phase two parallel branches in the embodiment of the application will be described in detail below in combination with FIG. 10. The connection mode of the stator winding at the crown end will be described below according to the solid line connection mode in FIG. 10, and the connection mode of the welding end of the stator winding can be referred to the dashed line connection mode.

[0278] As shown in FIG. 10, the first sub-branch of the U phase first branch is started from the 1st layer of the 10th slot as the incoming end U 1in from the 1st layer of the 10th slot, from the 2nd layer of the 20th slot, then from the 1st layer of the 29th slot, from the 2nd layer of the 38th slot, then from the 1st layer of the 47th slot, from the 2nd layer of the 2nd slot, then from the 1st layer of the 11th slot, from the 2nd layer of the 21st slot, then from the 1st layer of the 30th slot, from the 2nd layer of the 39th slot, then from the 1st layer of the 48th slot, from the 2nd layer of the 3rd slot, then from the 1st layer of the 12th slot, from the 2nd layer of the 19th slot, then from the 1st layer of the 28th slot, from the 2nd layer of the 37th slot, then from the 1st layer of the 46th slot, from the 2nd layer of the 1st slot, thus completing the traversal of the 1st layer and the 2nd layer flat wire.

[0279] The first sub-branch of the U-phase first branch starts from the 10th slot 3rd layer, enters from the 10th slot 3rd layer, exits from the 19th slot 4th layer, then enters from the 29th slot 3rd layer, exits from the 37th slot 4th layer, then enters from the 47th slot 3rd layer, exits from the 1st slot 4th layer, then enters from the 11th slot 3rd layer, exits from the 20th slot 4th layer, then enters from the 30th slot 3rd layer, exits from the 38th slot 4th layer, then enters from the 48th slot 3rd layer, exits from the 2nd slot 4th layer, then enters from the 12th slot 3rd layer, exits from the 18th slot 4th layer, then enters from the 28th slot 3rd layer, exits from the 36th slot 4th layer, then enters from the 46th slot 3rd layer, exits from the 54th slot 4th layer, thus completing the traversal of the 3rd and 4th layers of flat wires.

[0280] The third sub-branch of the U-phase first branch starts from the 10th slot 5th layer, enters from the 10th slot 5th layer, exits from the 20th slot 6th layer, then enters from the 29th slot 5th layer, exits from the 38th slot 6th layer, then enters from the 47th slot 5th layer, exits from the 2nd slot 6th layer, then enters from the 11th slot 5th layer, exits from the 18th slot 6th layer, then enters from the 27th slot 5th layer, exits from the 36th slot 6th layer, then enters from the 45th slot 5th layer, exits from the 54th slot 6th layer, then enters from the 9th slot 5th layer, exits from the 19th slot 6th layer, then enters from the 28th slot 5th layer, exits from the 37th slot 6th layer, then enters from the 46th slot 5th layer, exits from the 1st slot 6th layer, thus completing the traversal of the 5th and 6th layers of flat wires.

[0281] The fourth sub-branch of the U-phase first branch starts from the 10th slot 7th layer, enters from the 10th slot 7th layer, exits from the 19th slot 8th layer, then enters from the 29th slot 7th layer, exits from the 37th slot 8th layer, then enters from the 47th slot 7th layer, exits from the 1st slot 8th layer, then enters from the 11th slot 7th layer, exits from the 17th slot 8th layer, then enters from the 27th slot 7th layer, exits from the 35th slot 8th layer, then enters from the 45th slot 7th layer, exits from the 53rd slot 8th layer, then enters from the 9th slot 7th layer, exits from the 18th slot 8th layer, then enters from the 28th slot 7th layer, exits from the 36th slot 8th layer, then enters from the 46th slot 7th layer, exits from the 54th slot 8th layer, thus completing the traversal of the 7th and 8th layers of flat wires.

[0282] The first end of the fifth sub-branch of the first branch of the U-phase starts from the 10th slot of the 9th layer, enters from the 10th slot of the 9th layer, exits from the 17th slot of the 10th layer, then enters from the 26th slot of the 9th layer, exits from the 35th slot of the 10th layer, then enters from the 44th slot of the 9th layer, exits from the 53rd slot of the 10th layer, then enters from the 8th slot of the 9th layer, exits from the 18th slot of the 10th layer, then enters from the 27th slot of the 9th layer, exits from the 36th slot of the 10th layer, then enters from the 45th slot of the 9th layer, exits from the 54th slot of the 10th layer, then enters from the 9th slot of the 9th layer, exits from the 19th slot of the 10th layer, then enters from the 28th slot of the 9th layer, exits from the 37th slot of the 10th layer, then enters from the 46th slot of the 9th layer, exits from the 1st slot of the 10th layer, and thus completes the traversal of the flat wires of the 9th layer and the 10th layer.

[0283] Thus, the outgoing line end U of the first branch of the U-phase winding is formed by leading out from the 1st slot of the 10th layer. 1out .

[0284] The first end of the first sub-branch of the second branch of the U-phase starts from the 10th slot of the 10th layer as the incoming line end U 2in , enters from the 10th slot of the 10th layer, exits from the 54th slot of the 9th layer, then enters from the 45th slot of the 10th layer, exits from the 36th slot of the 9th layer, then enters from the 27th slot of the 10th layer, exits from the 18th slot of the 9th layer, then enters from the 9th slot of the 10th layer, exits from the 53rd slot of the 9th layer, then enters from the 44th slot of the 10th layer, exits from the 35th slot of the 9th layer, then enters from the 26th slot of the 10th layer, exits from the 17th slot of the 9th layer, then enters from the 8th slot of the 10th layer, exits from the 1st slot of the 9th layer, then enters from the 46th slot of the 10th layer, exits from the 37th slot of the 9th layer, then enters from the 28th slot of the 10th layer, exits from the 19th slot of the 9th layer, and thus completes the traversal of the flat wires of the 9th layer and the 10th layer.

[0285] The first end of the first sub-branch of the second branch of the U-phase starts from the 10th slot of the 8th layer, enters from the 10th slot of the 8th layer, exits from the 1st slot of the 7th layer, then enters from the 45th slot of the 8th layer, exits from the 37th slot of the 7th layer, then enters from the 27th slot of the 8th layer, exits from the 19th slot of the 7th layer, then enters from the 9th slot of the 8th layer, exits from the 54th slot of the 7th layer, then enters from the 44th slot of the 8th layer, exits from the 36th slot of the 7th layer, then enters from the 26th slot of the 8th layer, exits from the 18th slot of the 7th layer, then enters from the 8th slot of the 8th layer, exits from the 2nd slot of the 7th layer, then enters from the 46th slot of the 8th layer, exits from the 38th slot of the 7th layer, then enters from the 28th slot of the 8th layer, exits from the 20th slot of the 7th layer, and thus completes the traversal of the flat wires of the 7th layer and the 8th layer.

[0286] The first sub-branch of the second branch of the U-phase starts from the 10th slot 6th layer, enters from the 10th slot 6th layer, exits from the 54th slot 5th layer, then enters from the 45th slot 6th layer, exits from the 36th slot 5th layer, then enters from the 27th slot 6th layer, exits from the 18th slot 5th layer, then enters from the 9th slot 6th layer, exits from the 2nd slot 5th layer, then enters from the 47th slot 6th layer, exits from the 38th slot 5th layer, then enters from the 29th slot 6th layer, exits from the 20th slot 5th layer, then enters from the 11th slot 6th layer, exits from the 1st slot 5th layer, then enters from the 46th slot 6th layer, exits from the 37th slot 5th layer, then enters from the 28th slot 6th layer, exits from the 19th slot 5th layer, and thus completes the traversal of the flat wires of the 5th layer and the 6th layer.

[0287] The third sub-branch of the second branch of the U-phase starts from the 10th slot 4th layer, enters from the 10th slot 4th layer, exits from the 1st slot 3rd layer, then enters from the 45th slot 4th layer, exits from the 37th slot 3rd layer, then enters from the 27th slot 4th layer, exits from the 19th slot 3rd layer, then enters from the 9th slot 4th layer, exits from the 3rd slot 3rd layer, then enters from the 47th slot 4th layer, exits from the 39th slot 3rd layer, then enters from the 29th slot 4th layer, exits from the 21st slot 3rd layer, then enters from the 11th slot 4th layer, exits from the 2nd slot 3rd layer, then enters from the 46th slot 4th layer, exits from the 38th slot 3rd layer, then enters from the 28th slot 4th layer, exits from the 20th slot 3rd layer, and thus completes the traversal of the flat wires of the 3rd layer and the 4th layer.

[0288] The fourth sub-branch of the second branch of the U-phase starts from the 10th slot 2nd layer, enters from the 10th slot 2nd layer, exits from the 3rd slot 1st layer, then enters from the 48th slot 2nd layer, exits from the 39th slot 1st layer, then enters from the 30th slot 2nd layer, exits from the 21st slot 1st layer, then enters from the 12th slot 2nd layer, exits from the 2nd slot 1st layer, then enters from the 47th slot 2nd layer, exits from the 38th slot 1st layer, then enters from the 29th slot 2nd layer, exits from the 20th slot 1st layer, then enters from the 11th slot 2nd layer, exits from the 1st slot 1st layer, then enters from the 46th slot 2nd layer, exits from the 37th slot 1st layer, then enters from the 28th slot 2nd layer, exits from the 19th slot 1st layer, and thus completes the traversal of the flat wires of the 1st layer and the 2nd layer.

[0289] Thus, the outgoing line from the 19th slot 1st layer is formed, which is the outgoing end U of the second branch of the U-phase winding. 2out .

[0290] The wiring mode of the first branch of the V phase and the first branch of the W phase can be obtained by translating the wiring mode of the first branch of the U phase in FIG. 10. The wiring mode of the second branch of the V phase and the second branch of the W phase can be obtained by translating the wiring mode of the second branch of the U phase in FIG. 10.

[0291] As shown in FIGS. 5-10, it can be seen from the first embodiment to the sixth embodiment that the winding arrangement in the embodiments of the application is suitable for even layers with L / 2=odd number and even layers with L / 2=even number, which widens the flexibility of winding design. The plurality of flat wire groups are staggered by one slot, which can be equivalent to continuous short distance, and can weaken the winding 6k±1 (k=1 or 2) harmonic at the same time, and improve the NVH performance. Each flat wire in each parallel sub-winding of each phase is uniformly distributed in different layer positions in each pole slot, and the counter electromotive force and current of each parallel sub-winding are completely the same, which eliminates the additional copper loss caused by winding circulation due to winding parallel, ensures the uniformity of winding temperature, and further improves the service life of the motor. The three-phase lead-out wires are located at the first layer or the Lth layer, which can fully utilize the radial space and simplify the busbar structure. The card coil of each layer is independent, and there is no additional cross-layer card coil, which can realize full automation of the plug-in through independent wire cups, simplifies the manufacturing process, and is convenient for mass production.

[0292] The flat wire motor, power assembly and electric vehicle provided by the embodiments of the application are described in detail above, and the principles and embodiments of the application are described by applying specific examples. The above embodiment is only used to help understand the method and core idea of the application; at the same time, for those skilled in the art, according to the idea of the application, the specific embodiments and application range will be changed, and the above description should not be understood as a limitation of the application.

Claims

1. A flat wire motor, characterized by, The motor stator of the flat wire motor comprises a plurality of winding slots and N coils of flat wires, the N coils of flat wires are arranged radially along the flat wire motor, N is an integer greater than or equal to 2, each coil of the flat wires comprises a plurality of pairs of flat wires arranged circumferentially along the flat wire motor, each of the winding slots is used for accommodating one pair of the flat wires in each coil of the N coils of flat wires, each pair of the flat wires comprises an outer layer flat wire and an inner layer flat wire, the distance between the outer layer flat wire and the axis of the flat wire motor is greater than the distance between the inner layer flat wire and the axis of the flat wire motor along the radial direction of the flat wire motor, and one of the outer layer flat wires in each pair of the flat wires of each coil of the flat wires is used for connecting one of the inner layer flat wires in another pair of the flat wires. The N coils of flat wires comprise a first coil of flat wires, the outer layer flat wires in the first coil of flat wires comprise a first flat wire, a second flat wire and a third flat wire, and the first flat wire, the second flat wire and the third flat wire are respectively connected with the inner layer flat wires corresponding thereto through three cross-wire segments of different lengths.

2. The flat wire motor according to claim 1, characterized in that The difference between the slot number of the winding slot crossed by one cross-wire segment connected with the third flat wire and the slot number of the winding slot crossed by one cross-wire segment connected with the second flat wire is 1, and the difference between the slot number of the winding slot crossed by one cross-wire segment connected with the second flat wire and the slot number of the winding slot crossed by one cross-wire segment connected with the first flat wire is 2.

3. A flat wire motor according to claim 1 or 2, characterized in that The first flat wire and the inner layer flat wire connected therewith are arranged between the third flat wire and the inner layer flat wire connected therewith.

4. The flat wire motor of claim 3, wherein One of the first flat wires and one of the third flat wires are arranged adjacently, and one of the inner layer flat wires connected with the one first flat wire and one of the inner layer flat wires connected with the one third flat wire are spaced apart by one winding slot.

5. A flat wire motor according to any one of claims 1-4, characterized in that The outer layer flat wires in the first coil of flat wires comprise two third flat wires, and the two third flat wires are arranged adjacently on the same side of the first flat wire along the circumferential direction of the flat wire motor.

6. A flat wire motor according to any one of claims 1-5, characterized in that One of the inner layer flat wires connected with one of the first flat wires or one of the third flat wires and one of the second flat wires are arranged adjacently in one winding slot along the radial direction of the flat wire motor.

7. A flat wire motor according to any one of claims 1-6, characterized in that The outer layer flat wires in the first coil of flat wires comprise a plurality of second flat wires, and the plurality of second flat wires are arranged adjacently in sequence along the circumferential direction of the flat wire motor, and the plurality of second flat wires and the inner layer flat wires connected therewith are connected through the same cross-wire segment.

8. A flat wire motor according to any one of claims 1-7, characterized in that The N coils of flat wires further comprise a second coil of flat wires, the second coil of flat wires is arranged adjacently with the first coil of flat wires along the radial direction of the flat wire motor, the distance between the outer layer flat wires in the first coil of flat wires and the axis of the flat wire motor is greater than the distance between the outer layer flat wires in the second coil of flat wires and the axis of the flat wire motor along the radial direction of the flat wire motor, and one of the inner layer flat wires of the first coil of flat wires is used for fixedly connecting one of the outer layer flat wires of the second coil of flat wires through one cross-wire segment.

9. The flat wire motor of claim 8, wherein, The length of the cross-line segment between the inner layer flat wire of the first circle flat wire and the outer layer flat wire of the second circle flat wire connected thereto is less than or equal to the length of the cross-line segment between the third flat wire of the first circle flat wire and the inner layer flat wire connected thereto.

10. The flat wire motor of claim 9, wherein The difference between the slot number of the winding slot crossed by the cross-line segment between the third flat wire of the first circle flat wire and the inner layer flat wire connected thereto and the slot number of the winding slot crossed by the cross-line segment between the inner layer flat wire of the first circle flat wire and the outer layer flat wire of the second circle flat wire connected thereto is 1 or 2 or 3.

11. The flat wire motor of claim 8, wherein, The outer layer flat wire in the second circle flat wire includes the first flat wire, the second flat wire and the third flat wire, and the slot number of the winding slot crossed by the cross-line segment between the first flat wire in the first circle flat wire and the inner layer flat wire connected thereto is equal to the slot number of the winding slot crossed by the cross-line segment between the first flat wire in the second circle flat wire and the inner layer flat wire connected thereto.

12. The flat wire motor of claim 8, wherein, The outer layer flat wire in the second circle flat wire includes the first flat wire, the second flat wire and the third flat wire, and the difference between the slot number of the winding slot crossed by the cross-line segment between the first flat wire in the first circle flat wire and the inner layer flat wire connected thereto and the slot number of the winding slot crossed by the cross-line segment between the first flat wire in the second circle flat wire and the inner layer flat wire connected thereto is 1.

13. The flat wire motor of claim 8, wherein, The outer layer flat wire in the second circle flat wire includes the first flat wire, the second flat wire and the third flat wire, and the difference between the slot number of the winding slot crossed by the cross-line segment between the first flat wire in the first circle flat wire and the inner layer flat wire connected thereto and the slot number of the winding slot crossed by the cross-line segment between the first flat wire in the second circle flat wire and the inner layer flat wire connected thereto is 1.

14. A powertrain, characterized by, The power assembly includes a reducer and the flat wire motor of claim 13, the motor shaft of the flat wire motor is used for driving connection of the input shaft of the reducer, and the output shaft of the reducer is used for driving the wheels of the electric vehicle.

15. An electric vehicle, characterized by The electric vehicle includes a vehicle frame, a power battery and the power assembly of claim 14, the vehicle frame is used for fixing the power battery and the power assembly, the power battery is used for supplying power to the motor, and the motor is used for driving the wheels of the electric vehicle to travel through the reducer. The electric vehicle includes a vehicle frame, a power battery and the power assembly of claim 14, the vehicle frame is used for fixing the power battery and the power assembly, the power battery is used for supplying power to the motor, and the motor is used for driving the wheels of the electric vehicle to travel through the reducer.

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