Stator assembly, electric machine and vehicle

Abstract

The application provides a kind of stator assembly, motor and vehicle, stator assembly includes stator core and three-phase stator winding;Any one winding includes a parallel branch, a is 1 or 2, and when a is 2, 2 parallel branches are rotationally symmetric in the circumferential direction of stator core;Any one parallel branch contains multiple different span hairpin coils, hairpin coil only contains Z / P, (Z / P+1) and (Z / P-1) three spans, any one winding exists Z / P, (Z / P+1) and (Z / P-1) three span hairpin coils;8 slot layers of the same stator slot only exist hairpin coils of the same phase stator winding in the application. The magnetic field distribution of multiple parallel branches in each winding is the same, the magnetic potential is balanced, the circulating current between the parallel branches is avoided, the efficiency of the flat wire motor is improved, the local temperature rise of the winding is avoided, and the service life of the flat wire motor is prolonged.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric machines, and particularly relates to a stator assembly, an electric machine and a vehicle. BACKGROUND

[0002] With the popularization of new energy vehicles, new energy electric vehicles are becoming more and more popular, and the market demand for the performance of electric vehicle power systems is becoming higher and higher. The main drive motor is one of the core components of the electric vehicle, and is developing towards high power density and high torque density, small size and light weight. With the development of flat wire technology, the main drive motor of the electric vehicle gradually adopts flat wire winding, which can improve the slot fill factor of the stator, increase the cross-sectional area of the copper conductor, reduce the size of the motor, and further improve the power density, efficiency and thermal conductivity of the motor.

[0003] In the prior art, the flat wire motor mainly adopts wave winding or laminated winding structure. By designing the flat wire in the winding structure into a multi-layer structure, the alternating current resistance of the motor can be effectively reduced. However, with the increase in the number of flat wires, the wiring method of the winding structure is also different. In the prior art, when the stator winding branches of each phase are connected, the twisting direction of the coil slot outer end or the distance between the twisted slots is inconsistent, and various types of hairpin coils are used, which has complex manufacturing process, difficult forming, high production cost and low processing efficiency. In addition, due to the complex motor winding structure, potential imbalance easily occurs between the same phase branches, which causes circulating current to form between the branches, affecting the efficiency and temperature rise of the motor. SUMMARY

[0004] The present application provides a stator assembly, an electric machine and a vehicle, which can solve the problem of circulating current between multiple parallel branches of the three-phase winding of the motor stator in the prior art, and the complex production process and high manufacturing cost caused by the multiple types of hairpin coils.

[0005] To achieve the above technical effects, the technical scheme adopted by the stator of the present application is a stator assembly, comprising:

[0006] A stator core, the inner wall of which is uniformly distributed with Z stator slots in the circumferential direction, and each stator slot is divided into 8 slot layers along the radial direction of the stator core.

[0007] Three-phase stator windings are wound in the stator core and symmetrically distributed along the circumferential direction of the stator core; any phase winding of the three-phase stator windings comprises a strip of parallel branches, a is 1 or 2, and when a is 2, the two parallel branches are rotationally symmetric in the circumferential direction of the stator core; any parallel branch contains a plurality of hairpin coils of different spans, the hairpin coils only contain Z / P, (Z / P+1) and (Z / P-1) three spans, P is the number of motor poles; the hairpin coils of Z / P, (Z / P+1) and (Z / P-1) three spans exist in any parallel branch, and the hairpin coils of (Z / P+1) and (Z / P-1) spans are only located in the outermost layer or the innermost layer of the stator slot; when a is 2, the hairpin coils of (Z / P+1) and (Z / P-1) spans do not exist in each parallel branch at the same time; there are only hairpin coils of the same phase stator winding in the eight slot layers of the same stator slot.

[0008] When a=2, the voltage lead of the two parallel branches is respectively led out by the first slot layer of the adjacent two stator slots, and the neutral point lead is also respectively led out by the first slot layer of the adjacent two stator slots; and the voltage lead and the neutral point lead of one of the parallel branches are separated by 5 stator slots, and the voltage lead and the neutral point lead of the other parallel branch are separated by 7 stator slots.

[0009] When a=2, the span combination of the hairpin coils of the same layer of the outermost layer and the innermost layer of one of the parallel branches is (Z / P+1) and Z / P, and the ratio of the number of hairpin coils with span (Z / P+1) to the number of hairpin coils with span Z / P is 1:6; the span combination of the hairpin coils of the same layer of the outermost layer and the innermost layer of the other parallel branch is (Z / P-1) and Z / P, and the ratio of the number of hairpin coils with span (Z / P-1) to the number of hairpin coils with span Z / P is 1:6.

[0010] The span of the hairpin coil of the jth slot layer to the (j+1)th slot layer of any parallel branch is Z / P, and the welding span of the jth slot layer to the (j+1)th slot layer of any parallel branch is Z / P, j is a positive integer, and j<8.

[0011] The hairpin coil comprises a U-shaped hairpin coil and an I-shaped hairpin coil, the U-shaped hairpin coil comprises a bent connecting section and two straight sections inserted into two different stator slots respectively, and two welding sections protruding outside the end surface of the stator core, two ends of the bent connecting section are connected to the same end of the two straight sections respectively, and the same end of the two welding sections is connected to the other end of the two straight sections respectively; all the bent connecting sections of the U-shaped hairpin coils are located at one end of the stator core to form a winding hairpin end, all the welding sections of the U-shaped hairpin coils are located at the other end of the stator core, and the adjacent welding sections of adjacent U-shaped hairpin coils are welded together to form a winding welding end.

[0012] The span of the hairpin coil is the number of stator slots crossed by the two straight sections of the U-shaped hairpin coil.

[0013] The voltage lead and the neutral point lead of any phase stator winding are connected in star or triangle.

[0014] The application further provides a motor comprising the stator assembly and a rotor.

[0015] The application further provides a vehicle comprising the motor.

[0016] Compared with the prior art, the application has the following advantages and positive effects:

[0017] 1. The three-phase stator windings of the stator assembly are symmetrically distributed along the circumferential direction of the stator core, and when any phase winding comprises two parallel branches, the two parallel branches are also rotationally symmetric in the circumferential direction of the stator core, so that the magnetic field distribution of the multiple parallel branches in each phase winding is the same, the magnetic potential is balanced, the circulating current between the parallel branches is avoided, the efficiency of the flat wire motor is improved, the local temperature rise of the winding is avoided, and the service life of the flat wire motor is prolonged.

[0018] 2. Any parallel branch contains multiple hairpin coils with different spans, the multiple hairpin coils contain only three spans of (Z / P+1), Z / P and (Z / P-1), any phase winding contains hairpin coils with the three spans of Z / P, (Z / P+1) and (Z / P-1), when two parallel branches are contained, the two parallel branches do not simultaneously contain the two spans of (Z / P+1) and (Z / P-1), the hairpin coils with the spans of (Z / P+1) and (Z / P-1) are only located at the outermost layer or the innermost layer of the stator slots, and only the hairpin coils of the same phase stator winding are contained in the same stator slot, so that the types of the hairpin coils are few, and the automatic production is facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a three-dimensional structural diagram of the stator assembly of the motor in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the three-dimensional structure of the stator core of the stator assembly in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the U-shaped hairpin coil structure in an embodiment of the present invention;

[0023] Figure 4 This is a circuit diagram showing that the two parallel branches of each phase winding in the three-phase stator winding of the stator assembly in an embodiment of the present invention are connected in a star configuration.

[0024] Figure 5 This is a circuit diagram showing that the two parallel branches of each phase winding in the three-phase stator winding of the stator assembly in an embodiment of the present invention are connected in a delta configuration.

[0025] Figure 6 This is a diagram showing the winding configuration of the first parallel branch of the A-phase winding of an 8-pole 48-slot motor in an embodiment of the present invention.

[0026] Figure 7 for Figure 6 Enlarged view of the middle section (I);

[0027] Figure 8 This is a diagram showing the winding configuration of the second parallel branch of the A-phase winding of an 8-pole 48-slot motor in an embodiment of the present invention.

[0028] Figure 9 for Figure 8 Enlarged view of Part II;

[0029] Figure 10 This is a diagram showing the winding configuration of phase A of an 8-pole, 48-slot motor according to an embodiment of the present invention.

[0030] Figure 11 for Figure 10 Enlarged view of Part III;

[0031] Figure 12 This is a diagram showing the winding configuration of the three-phase winding of an 8-pole, 48-slot motor in an embodiment of the present invention.

[0032] Figure 13 for Figure 12Fig. 4 is a zoomed-in view of section IV of Fig. 1;

[0033] Figure 1 4 isFig. 5 is a zoomed-in view of section V of Fig. 1. Figure 12

[0034] Reference signs: 10, stator assembly; 11, stator core; 12, three-phase stator winding; 13, stator slot; 20, U-shaped hairpin coil; 21, bent connecting section; 22, straight section; 23, welded section. DETAILED DESCRIPTION

[0035] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms “mounting”, “connection”, “connecting” should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be directly connected, or indirectly connected through an intermediate medium, can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In addition, the technical features involved in the different embodiments of the application described below can be combined with each other as long as there is no conflict.

[0037] For the convenience of understanding, the professional terms appearing in the present application are explained as follows.

[0038] Stator: refers to the stationary part in the motor, which functions to generate a rotating magnetic field.

[0039] Rotor: refers to the rotating part in the motor, which functions to realize the conversion of electrical energy and mechanical energy.

[0040] The embodiment of the present application provides a motor, which comprises a rotor and a stator assembly 10, and the rotor is arranged in a space formed by the inner wall of the stator core 11 of the stator assembly 10. Figure 1 and Figure 2 As shown in the drawings, the stator assembly 10 comprises a stator core 11 and a three-phase stator winding 12 wound in the stator core 11, and the inner wall of the stator core 11 is uniformly provided with Z stator slots 13 in the circumferential direction, each stator slot 13 is divided into 8 slot layers along the radial direction of the stator core 11, and the three-phase stator winding 12 is symmetrically distributed along the circumferential direction of the stator core 11. Wherein, Z is a positive integer.

[0041] As shown in the drawings, the voltage lead and the neutral point lead of the three-phase stator winding are connected in star or triangle. Figure 4 and Figure 5 As shown in the drawings, the voltage lead and the neutral point lead of the three-phase stator winding are connected in star or triangle.

[0042] Each stator slot 13 is divided into 8 slot layers along the radial direction of the stator core 11, the 1st layer is denoted as D1, the 2nd layer is denoted as D2, the 3rd layer is denoted as D3, the 4th layer is denoted as D4, the 5th layer is denoted as D5, the 6th layer is denoted as D6, the 7th layer is denoted as D7, and the 8th layer is denoted as D8. The 1st slot layer is the slot bottom layer of the stator slot 13, and the 8th slot layer is the slot opening layer, or the 1st slot layer is the slot opening layer of the stator slot 13, and the 8th slot layer is the slot bottom layer. The slot opening layer is also referred to as the innermost layer, and the slot bottom layer is also referred to as the outermost layer.

[0043] Any one of the three-phase stator windings 12 (A-phase winding, B-phase winding and C-phase winding) includes a parallel branch a, a is 1 or 2, and when a is 2, the two parallel branches of each phase winding are also rotationally symmetrical in the circumferential direction of the stator core 11. By limiting the rotational symmetry of the two parallel branches in each phase winding in the circumferential direction, the magnetic field distribution of the two parallel branches in each phase winding is the same, the magnetic potential is balanced, and the circulating current between the parallel branches is avoided, thereby greatly reducing the additional alternating current copper loss under high speed working condition, improving the efficiency of the flat wire motor, and avoiding local temperature rise of the winding. Overheating, prolonging the service life of the flat wire motor.

[0044] At the same time, any one parallel branch contains multiple hairpin coils with different spans, all hairpin coils only have Z / P, (Z / P+1) and (Z / P-1) three spans, P is the number of motor poles, and any one phase winding has Z / P, (Z / P+1) and (Z / P-1) three span hairpin coils, when there are two parallel branches, any one parallel branch does not have (Z / P+1) and (Z / P-1) two spans, and the hairpin coils with spans of (Z / P+1) and (Z / P-1) are only located in the outermost layer or the innermost layer of the stator slot 13; when a is 2, the hairpin coils with spans of (Z / P+1) and (Z / P-1) do not exist in each parallel branch; and only the hairpin coils of the same phase stator winding exist in the 8 slot layers of the stator slot 13, so that the type of hairpin coil is less, which is beneficial to simplify the manufacturing process, reduce the production cost, and facilitate automatic production.

[0045] Among them, the hairpin coils of each parallel branch include U-shaped hairpin coils 20 and I-shaped hairpin coils, the I-shaped hairpin coils are the wire inlet and outlet ends of each parallel branch, and the U-shaped hairpin coils 20 are located between the two I-shaped hairpin coils, that is, each parallel branch only contains two I-shaped hairpin coils, and the rest are U-shaped hairpin coils 20.

[0046] As Figure 3As shown, the U-shaped hairpin coil 20 is formed by a flat wire conductor with a rectangular cross-section, including a bent connecting section 21, two straight sections 22, and two welded sections 23. The two straight sections 22 are used to be inserted into two different stator slots 13 respectively. Both the bent connecting section 21 and the welded sections 23 protrude from the outer side of the end face of the stator core 11. The two ends of the bent connecting section 21 are respectively connected to the same end of the two straight sections 22, and the same end of the two welded sections 23 are respectively connected to the other end of the two straight sections 22. This can eliminate the potential phase difference caused by the position of multiple parallel branches in each phase winding in the stator slot 13.

[0047] by Figure 3 From the perspective shown, the two ends of the bent connecting section 21 are respectively connected to the top ends of the two straight sections 22, and the top ends of the two welded sections 23 are respectively connected to the bottom ends of the two straight sections 22. All bent connecting sections 21 of the U-shaped hairpin coils 20 are located at one end of the stator core 11, forming the winding insertion end. All welded sections 23 of the U-shaped hairpin coils 20 are located at the other end of the stator core 11. Adjacent welded sections 23 of adjacent U-shaped hairpin coils 20 are welded together to form the winding welding end. For example, the bottom end of the right welded section 23 of the left U-shaped hairpin coil 20 is welded to the bottom end of the left welded section 23 of the right U-shaped hairpin coil 20. The span refers to the number of stator slots 13 crossed by the two straight sections 22 of the U-shaped hairpin coil 20; the welding pitch between hairpin coils is the number of stator slots crossed by the adjacent straight sections 22 of two adjacent hairpin coils.

[0048] The type I hairpin coil is equivalent to half the size of the type U hairpin coil (20). Figure 3 From the perspective shown, the type I hairpin coil is equivalent to the left or right half of the type U hairpin coil 20, and its structure will not be described in detail.

[0049] In some embodiments of this application, the U-shaped hairpin coil 20 can be inserted into the stator slot 13 and then the U-shaped hairpin coil 20 can be bent to form a welding section 23. After the U-shaped hairpin coil 20 is inserted into the stator slot 13, its bent connecting section 21 forms the winding insertion end, and the welding section 23 forms the winding welding end.

[0050] Furthermore, when a=2, the voltage leads of the two parallel branches are respectively led out from the first slot layer of two adjacent stator slots, that is, the voltage lead of one parallel branch is led out from the first slot layer of one of the two adjacent stator slots, and the voltage lead of the other parallel branch is led out from the first slot layer of the other of the two adjacent stator slots; the neutral point leads of the two parallel branches are also respectively led out from the first slot layer of two adjacent stator slots, that is, the neutral point lead of one parallel branch is led out from the first slot layer of one of the two adjacent stator slots, and the neutral point lead of the other parallel branch is led out from the first slot layer of the other of the two adjacent stator slots; in the two parallel branches, the voltage lead and the neutral point lead of one parallel branch are separated by 5 stator slots, and the voltage lead and the neutral point lead of the other parallel branch are separated by 7 stator slots.

[0051] The above winding method facilitates the welding of motor terminals and busbars, and the winding method of each parallel branch is simple, which makes winding convenient, simplifies the manufacturing process, reduces production costs, and facilitates automated production.

[0052] The following embodiments use an example where the motor has 8 poles P, the stator slots 13 have 48 slots Z, each stator slot 13 contains 8 slot layers, and each phase winding of the three-phase stator winding 12 includes 2 parallel branches to illustrate the winding structure of each phase winding of the stator in this invention.

[0053] The U-shaped hairpin coil 20 of the stator assembly 10 in this embodiment has only three spans: (Z / P+1), (Z / P-1), and Z / P, i.e., 7, 6, and 5. The stator assembly 10 is composed of three-phase stator windings 12 (A-phase winding, B-phase winding, and C-phase winding) with a phase difference of 120 electrical degrees, and the three-phase stator windings 12 are wound in the stator core 11.

[0054] like Figures 6 to 14 As shown, and in combination Figure 2 The numbers 1 to 48 arranged horizontally represent the slot numbers of stator slot 13, and are arranged in a ring. Figures 6 to 14 The eight vertical lines corresponding to each number from 1 to 48 represent slot layers 1 to 8, for a total of eight slot layers. A1 and A2 can be used as voltage leads or neutral point leads. Correspondingly, X1 and X2 can be used as voltage leads or neutral point leads. For example, A1 is used as the voltage lead of the first parallel branch of the A-phase winding, and X1 is used as the neutral point lead of the first parallel branch of the A-phase winding; A2 is used as the voltage lead of the second parallel branch of the A-phase winding, and X2 is used as the neutral point lead of the second parallel branch of the A-phase winding.

[0055] Similarly, B1 and B2 can be used as voltage leads or neutral point leads for the B-phase winding. Correspondingly, Y1 and Y2 can be used as voltage leads or neutral point leads. For example, B1 can be used as the voltage lead for the first parallel branch of the B-phase winding, and Y1 can be used as the neutral point lead for the first parallel branch of the B-phase winding; B2 can be used as the voltage lead for the second parallel branch of the B-phase winding, and Y2 can be used as the neutral point lead for the second parallel branch of the B-phase winding.

[0056] C1 and C2 can be used as voltage leads or neutral point leads for the C-phase winding. Similarly, Z1 and Z2 can be used as voltage leads or neutral point leads. For example, C1 can be used as the voltage lead for the first parallel branch of the C-phase winding, and Z1 can be used as the neutral point lead for the first parallel branch of the C-phase winding; C2 can be used as the voltage lead for the second parallel branch of the C-phase winding, and Z2 can be used as the neutral point lead for the second parallel branch of the C-phase winding.

[0057] Specifically, such as Figures 6 to 14 As shown, the voltage lead A1 of the first parallel branch of phase A winding is led out from the first layer of slot 1, and the voltage lead A2 of the second parallel branch is led out from the first layer of slot 2; the neutral point lead X1 of the first parallel branch of phase A winding is led out from the first layer of slot 44, and the neutral point lead X2 of the second parallel branch is led out from the first layer of slot 43; the voltage lead A1 and the neutral point lead X1 of the first parallel branch of phase A winding are separated by 5 stator slots, namely slots 44, 45, 46, 47, 48, and 1. Since slots 44 and 1 are the lead slots for A1 and X1 respectively, when calculating the number of stator slots separated, Slot 44 and Slot 1 can each be considered as spanning half a slot. Therefore, the voltage lead A1 and neutral point lead X1 of the first parallel branch of the A-phase winding are separated by 5 stator slots. The voltage lead A2 and neutral point lead X2 of the second parallel branch of the A-phase winding are separated by 7 stator slots, namely slots 43, 44, 45, 46, 47, 48, 1, and 2. Since slots 43 and 2 are the lead slots for A2 and X2 respectively, when calculating the number of stator slots separated, slots 43 and 2 can each be considered as spanning half a slot. Therefore, the voltage lead A2 and neutral point lead X2 of the second parallel branch of the A-phase winding are separated by 7 stator slots.

[0058] In some embodiments of this application, when a=2, the span combinations of the outermost and innermost hairpin coils in one parallel branch are (Z / P+1) and Z / P, and the ratio of the number of hairpin coils with a span of (Z / P+1) to the number of hairpin coils with a span of Z / P is 1:6; the span combinations of the outermost and innermost hairpin coils in another parallel branch are (Z / P-1) and Z / P, and the ratio of the number of hairpin coils with a span of (Z / P-1) to the number of hairpin coils with a span of Z / P is 1:6. Therefore, fewer types of hairpin coil spans in the same layer result in fewer types of hairpin coil wire types used, facilitating motor winding and automated production.

[0059] Specifically, such as Figures 6 to 9 Taking a motor with 8 poles (P) and 48 stator slots (Z) as an example, then Z / P+1=7, Z / P=6, and Z / P-1=5. In the first parallel branch of phase A winding, the outermost and innermost span combinations are 7 and 6. Specifically, the outermost and innermost spans in the first parallel branch are only 7 and 6, and the number of hairpin coils with a span of 7 in the same layer is 1, while the number of hairpin coils with a span of 6 in the same layer is 6, with a ratio of 1:6. In the second parallel branch of phase A winding, the outermost and innermost span combinations are 5 and 6. Specifically, the outermost and innermost spans in the second parallel branch are only 5 and 6, and the number of hairpin coils with a span of 5 in the same layer is 1, while the number of hairpin coils with a span of 6 in the same layer is 6, with a ratio of 1:6.

[0060] In some embodiments of this application, slot number i(j) represents the j-th slot layer in the i-th slot. For example, 1(1) below represents the 1-th slot layer in the 1-th slot, or simply the 1-th slot layer, and 7(2) below represents the 2-th slot layer in the 7-th slot, or simply the 7-th slot layer. Other slot numbers below are explained in the same way.

[0061] In some embodiments of this application, the hairpin coil span from the j-th slot layer to the (j+1)-th slot layer of any parallel branch is Z / P, and the welding span of the same parallel branch from the j-th slot layer to the (j+1)-th slot layer is also Z / P, where j is a positive integer and j<8. That is, the non-same-layer hairpin coil span and non-same-layer welding span of any parallel branch are equal, resulting in fewer types of U-shaped hairpin coil 20 wires and only one type of welding span, further facilitating welding and automated manufacturing.

[0062] like Figure 6 and Figure 7 As shown, the first parallel branch of phase A enters from position A1 (slot 1, layer 1) and exits from position X1 (slot 44, layer 1) to the three-phase center point. The slot numbers traversed by the first parallel branch in series are:

[0063] 1(1)-7(2)-13(3)-19(4)-25(5)-31(6)-37(7)-43(8)-1(8)-43(7)-37(6)-31(5)-25(4)-19(3)-13(2)-7(1)-13(1)-19(2)-25(3)-31(4)-37(5)-43(6)-1(7)-7(8)-13(8)-7(7)-1(6)-43(5)-37(4)-31(3)-25(2)-19(1)- 26(1)-32(2)-38(3)-44(4)-2(5)-8(6)-14(7)-20(8)-26(8)-20(7)-14(6)-8(5)-2(4)-44(3)-38(2)-32(1)-38(1)-44(2)-2(3)-8(4)-14(5)-20(6)-26(7)-32(8)-38(8)-32(7)-26(6)-20(5)-14(4)-8(3)-2(2)-44(1).

[0064] like Figure 8 and Figure 9 As shown, the second parallel branch of phase A winding enters at position A2 (slot 2, layer 1) and exits at position X2 (slot 43, layer 1) to the three-phase center point. The slot numbers traversed by the second parallel branch in series are:

[0065] 2(1)-8(2)-14(3)-20(4)-26(5)-32(6)-38(7)-44(8)-2(8)-44(7)-38(6)-32(5)-26(4)-20(3)-14(2)-8(1)-14(1)-20(2)-26(3)-32(4)-38(5)-44(6)-2(7)-8(8)-14(8)-8(7)-2(6)-44(5)-38(4)-32(3)-26(2)-20(1)- 25(1)-31(2)-37(3)-43(4)-1(5)-7(6)-13(7)-19(8)-25(8)-19(7)-13(6)-7(5)-1(4)-43(3)-37(2)-31(1)-37(1)-43(2)-1(3)-7(4)-13(5)-19(6)-25(7)-31(8)-37(8)-31(7)-25(6)-19(5)-13(4)-7(3)-1(2)-43(1).

[0066] The start slot number and the end slot number corresponding to the two parallel branch windings are distributed as follows: A1 corresponds to 1(1), X1 corresponds to 44(1); A2 corresponds to 2(1), X2 corresponds to 43(1); the cross-layer hairpin coil span of the two branch windings is 6, the same-layer hairpin coil span is 6, 7 or 5, 6, the welding end hairpin coil span is 6; the two branch windings are completely symmetrical in the circumference, and there is no branch circulating current caused by potential difference.

[0067] The A-phase winding, the B-phase winding and the C-phase winding are symmetrically and uniformly distributed on the circumference of the stator core 11, and the winding mode of the B-phase winding and the C-phase winding will not be described here.

[0068] Preferably, the three-phase voltage lead-out lines of the A-phase winding, the B-phase winding and the C-phase winding are lead out in the same slot layer, which facilitates the welding of the terminal copper bars.

[0069] Preferably, as shown in Figures 12 to 14 The neutral point lead-out lines X1, X2, Y1, Y2, Z1 and Z2 of the six parallel branches of the A-phase winding, the B-phase winding and the C-phase winding only span 9 slots, i.e., the 43rd slot, the 44th slot, the 45th slot, the 46th slot, the 47th slot, the 48th slot, the 1st slot, the 2nd slot, the 3rd slot and the 4th slot, wherein the 43rd slot and the 4th slot are the head and tail of the slots spanned by the neutral point lead-out lines X1, X2, Y1, Y2, Z1 and Z2, and thus the 43rd slot and the 4th slot can be equivalent to spanning half a slot, so that a total of 9 slots are spanned, the length of the star point copper bar can be greatly reduced, which is beneficial to saving resources and reducing costs, and effectively reduces the star point copper bar resistance and reduces heat generation, and improves the motor efficiency.

[0070] The embodiment also provides a vehicle comprising the motor described above, and details thereof will not be described here.

[0071] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A stator assembly characterized by, The stator core has Z stator slots uniformly distributed on the inner wall in the circumferential direction, and each of the stator slots is divided into 8 slot layers in the radial direction of the stator core. The three-phase stator winding is wound in the stator core and symmetrically distributed in the circumferential direction of the stator core; any phase winding of the three-phase stator winding includes two parallel branches, and the two parallel branches are rotationally symmetric in the circumferential direction of the stator core; any parallel branch contains a plurality of hairpin coils with different spans, and the hairpin coils only contain three spans of Z / P, (Z / P+1) and (Z / P-1), P being the number of motor poles; the hairpin coils with spans of Z / P, (Z / P+1) and (Z / P-1) exist in any phase winding, and the hairpin coils with spans of (Z / P+1) and (Z / P-1) are only located in the outermost layer or the innermost layer of the stator slots; the hairpin coils with spans of (Z / P+1) and (Z / P-1) do not exist in each parallel branch at the same time, the span combination of the hairpin coils in the same layer of the outermost layer and the innermost layer of one of the parallel branches is (Z / P+1) and Z / P, and the ratio of the number of hairpin coils with a span of (Z / P+1) to the number of hairpin coils with a span of Z / P is 1:6, the span combination of the hairpin coils in the same layer of the outermost layer and the innermost layer of the other parallel branch is (Z / P-1) and Z / P, and the ratio of the number of hairpin coils with a span of (Z / P-1) to the number of hairpin coils with a span of Z / P is 1:6; only the hairpin coils of the same phase stator winding exist in the 8 slot layers of the same stator slot.

2. The stator assembly of claim 1, wherein the voltage lead lines of the two parallel branches are respectively led out by the first slot layers of the two adjacent stator slots, and the neutral point lead lines are also respectively led out by the first slot layers of the two adjacent stator slots; and the voltage lead line and the neutral point lead line of one of the parallel branches are separated by 5 stator slots, and the voltage lead line and the neutral point lead line of the other parallel branch are separated by 7 stator slots.

3. The stator assembly of claim 1 or 2, wherein the span of the hairpin coils of the any parallel branch in the jth slot layer to the (j+1)th slot layer is Z / P, and the welding span of the any parallel branch in the jth slot layer to the (j+1)th slot layer is Z / P, j being a positive integer and j<8.

4. The stator assembly of claim 1, wherein ​ ​ ​ The hairpin coil comprises a U-shaped hairpin coil and an I-shaped hairpin coil, the U-shaped hairpin coil comprises a bent connecting section and two straight sections respectively inserted into two different stator slots, and two welding sections protruding outside the end surface of the stator core, two ends of the bent connecting section are respectively connected to the same end of the two straight sections, and the same end of the two welding sections is respectively connected to the other end of the two straight sections; all the bent connecting sections of the U-shaped hairpin coils are located at one end of the stator core to form a winding hairpin end, all the welding sections of the U-shaped hairpin coils are located at the other end of the stator core, and adjacent welding sections of adjacent U-shaped hairpin coils are welded together to form a winding welding end. The span of the hairpin coil is the number of stator slots crossed by the two straight sections of the U-shaped hairpin coil.

5. The stator assembly of claim 1, wherein The voltage lead and the neutral point lead of any phase stator winding are connected in star or delta.

6. An electric machine comprising a stator assembly and a rotor, characterized by The stator assembly is any one of claims 1-5.

7. A vehicle characterized by comprising: The motor comprises the stator assembly of claim 6.

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