Stator, flat wire motor, power train and vehicle

Abstract

The present application discloses a stator, a flat wire motor, a power train, and a vehicle. The stator includes a stator core having a plurality of stator slots uniformly arranged along its circumferential direction on an inner wall, and a stator winding. Each phase winding includes a plurality of parallel branch paths that are rotationally symmetric in the circumferential direction. Each parallel branch path includes a plurality of hairpin coils connected by connecting wires and having different pitches. N layers of hairpin coils are provided in any stator slot. The hairpin coils of each parallel branch path are provided across N slot layers in different stator slots. When N = (2n + 1) × 2, the combination of the total number of slot layers occupied by each parallel branch path in each stator slot is 2n, or 2n, 2n - 1, 2n - 2. When N = 2n × 2, the combination of the total number of slot layers occupied by each parallel branch path in each stator slot is 2n, 2n - 1, or 2n, 2n - 1, 2n - 2. When N = 2n + 1, the combination of the total number of slot layers occupied by each parallel branch path in each stator slot is n, n - 1, or n, n - 1, n - 2. By the above method, the stator according to the present application can avoid the generation of circulating current, reduce the manufacturing cost, and improve the efficiency of processing and manufacturing.

Description

Technical Field

[0001] The present application relates to the technical field of flat wire motors, and in particular, to stators, flat wire motors, power trains and vehicles.

Background Art

[0002] With the active promotion of the sales of new energy vehicles, new energy electric vehicles are becoming increasingly popular, and the market's requirements for the performance of the power system of electric vehicles are increasing. The main drive motor is the power output member of the power system and one of the most important components of an electric vehicle. The requirements for the performance indicators of the main drive motor are also increasing. For example, high power density, torque density, miniaturization and weight reduction are required. With the development of the flat wire process, the motors of electric vehicles are gradually using flat wire windings, which can improve the occupancy rate of the stator slots and further improve the power density, efficiency and thermal conductivity of the motor.

[0003] Conventional motors mainly use wave windings or overlapping winding structures. By designing flat wire conductors in the winding structure in multiple layers, the AC resistance of the motor can be effectively reduced. However, with the increase in the number of layers of flat wire conductors, the wiring methods of the winding structure are not the same. Currently, multiple parallel branch paths are usually provided in the three-phase windings of the winding structure, and circulating currents are likely to occur between the branch paths. In addition, there are many wire types of hairpin coils, the production process is complex, and the manufacturing cost is high.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Based on this, the present invention provides a stator, a flat wire motor, a power train and a vehicle.

Means for Solving the Problems

[0005] According to the first aspect, the present invention provides a stator core having a plurality of status slots uniformly arranged along its circumferential direction on an inner wall, and a stator winding, wherein the stator winding includes a three-phase winding, each phase winding includes a plurality of parallel branch paths, the plurality of parallel branch paths are rotationally symmetric in the circumferential direction, each of the parallel branch paths includes a plurality of hairpin coils connected by connection wires and having different pitches, N layers of the hairpin coils are provided in any of the status slots, the hairpin coils of each parallel branch path are provided across N slot layers in different status slots, the three-phase windings are sequentially and periodically arranged along the circumferential direction of the stator core. When N = (2n + 1) × 2, the combination of the total number of slot layers occupied by each parallel branch path in each status slot is 2n, or 2n, 2n - 1, 2n - 2. When N = 2n × 2, the combination of the total number of slot layers occupied by each parallel branch path in each status slot is 2n, 2n - 1, or 2n, 2n - 1, 2n - 2. When N = 2n + 1, the combination of the total number of slot layers occupied by each parallel branch path in each status slot is n, n - 1, or n, n - 1, n - 2. N is a positive integer and is 4 or more, and the total number of slot layers of each parallel branch path in each status slot is also a positive integer, providing a stator of a flat wire motor.

[0006] Furthermore, when the total number of slot layers occupied by each of the parallel branch paths in the status slot is 1, the position of the one slot layer is the first layer or the Nth layer of the status slot. When the total number of slot layers occupied by each of the parallel branch paths in the status slot is 2, the two slot layers are provided adjacent to each other in the status slot, or the two slot layers are the first layer and the Nth layer in the status slot, respectively. When the total number of slot layers occupied by each of the parallel branch paths in the status slot is 3, two of the three slot layers are provided adjacent to each other, the position of the remaining one slot layer is the first layer or the Nth layer of the status slot, and the remaining one slot layer is provided with a separation of four slot layers from the other two slot layers. When the total number of slot layers occupied by each of the parallel branch paths in the status slot is 4, the four slot layers are divided into two groups, each group is provided with a separation of four slot layers, and each group includes two adjacent slot layers.

[0007] Furthermore, each phase winding includes three parallel branch paths.

[0008] Furthermore, the number of the status slots is 54 or 72.

[0009] Furthermore, the combinations of the pitches of the hairpin coils in each of the parallel branch paths are 8, 9, 11, 12, and 16.

[0010] Furthermore, the pitch of the hairpin coils in the same slot layer of each of the parallel branch paths is 9.

[0011] Furthermore, the pitch of the hairpin coils in the first slot layer or the Nth slot layer of each of the parallel branch paths is 8 or 8, 11.

[0012] Furthermore, for each of the parallel branch paths, the incoming line end is located in the Nth layer of the slot layer, the outgoing line end is located in the N - 1th layer of the slot layer, or the incoming line end and the outgoing line end of each of the parallel branch paths are both located in the first slot layer and the Nth slot layer.

[0013] Furthermore, the welding pitch between the hairpin coils in each of the parallel branch paths is 9 or 11 in each case.

[0014] Furthermore, each of the parallel branch paths includes a long-pitch hairpin coil with a pitch of s / (2p)+a, a full-pitch hairpin coil with a pitch of s / (2p), and a short-pitch hairpin coil with a pitch of s / (2p)+a - 4. s is the number of stator slots, p is the number of parallel branch paths, and a is an integer of 2 or more and 4 or less.

[0015] Furthermore, in each of the parallel branch paths, the first leg and the second leg of the short-pitch hairpin coil are respectively located in the k-th slot layer and the k + 1-th slot layer, the first leg and the second leg of the long-pitch hairpin coil are respectively located in the k + 1-th slot layer and the k + 2-th slot layer, the first leg and the second leg of the full-pitch hairpin coil are both distributed in the first slot layer or the n-th slot layer, and k is an odd number of 1 or more and n or less.

[0016] Furthermore, the number of slots per pole per phase of the flat wire motor is q, the voltage lead-out wires of the p parallel branch paths of each phase winding are located within s of the stator slots and are located in the same slot layer or adjacent slot layers of different stator slots, and the neutral point lead-out wires of the p parallel branch paths of each phase winding are located within s of the stator slots and are located in the same slot layer or adjacent slot layers of different stator slots.

[0017] Furthermore, both the voltage lead-out wires and the neutral point lead-out wires are located in the first slot layer or the n-th slot layer.

[0018] Furthermore, the welding pitch between the hairpin coils in each of the parallel branch paths is s / (2p) in each case.

[0019] Furthermore, n is an even number, a = 4, the short-pitch-wound hairpin coil is the full-pitch-wound hairpin coil, in the phase belt distribution of the three-phase winding, the polarity distributions of each odd layer are the same, the polarity distributions of each even layer are the same, and with respect to the polarity distribution of the odd layer, it is shifted by one status slot.

[0020] Furthermore, the number of slot layers of the status slot is one of 4, 6, 8, and 10, the combinations of the pitches of the hairpin coils in each of the parallel branch paths are 10, 12, 14, and the welding pitch between the hairpin coils in each of the parallel branch paths is all 13.

[0021] Furthermore, each of the hairpin coils includes a first leg, a second leg, a connection segment, a first bending segment, and a second bending segment. The first leg and the second leg are provided in parallel and are inserted into the slot layers of different status slots respectively. The connection segment is connected to one ends of the first leg and the second leg. The first bending segment is connected to the other end of the first leg. The second bending segment is connected to the other end of the second leg. Welding ends are connected to both the first bending segment and the second bending segment.

[0022] Furthermore, the bending directions of the first bending segment and the second bending segment are the same and parallel, or are provided symmetrically.

[0023] According to a second aspect, the present invention provides a flat wire motor including a rotor and any one of the above stators, wherein the rotor is provided in a space surrounded by the inner wall of the stator core.

[0024] According to a third aspect, the present invention provides a power train including a speed reducer and a flat wire motor as described above, wherein the flat wire motor is transmission-connected to the speed reducer.

[0025] According to a fourth aspect, the present invention provides a vehicle including the power train as described above.

Advantages of the Invention

[0026] The beneficial effects of the present application are as follows. Different from the prior art, the present application discloses a stator, a flat wire motor, a power train, and a vehicle. The plurality of parallel branch paths of each phase winding are rotationally symmetric in the circumferential direction. In this way, the magnetic field distributions of the plurality of parallel branch paths in each phase winding are the same, and the potentials are balanced, so as to avoid the circulating current generated between the parallel branch paths, greatly reduce the additional AC copper loss at high frequencies, improve the efficiency of the flat wire motor during high-speed operation, avoid local overheating of the winding, extend the service life of the flat wire motor, and further, the hairpin coils of each parallel branch path are provided across N slot layers in different stator slots. Thereby, the potential phase difference due to the positions in the stator slots of the plurality of parallel branch paths of each phase winding can be eliminated. By limiting the number of slot layers N in the stator slots and the total number of slot layers occupied by each corresponding parallel branch path in each stator slot, the wire type of the hairpin coil can be reduced, the manufacturing mold of the flat wire motor can be reduced, the manufacturing cost can be reduced, and the processing and manufacturing efficiency can be effectively improved.

Brief Description of the Drawings

[0027]

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Embodiments for Carrying out the Invention

[0028] Hereinafter, while referring to the drawings in the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor shall fall within the protection scope of the present application.

[0029] In the embodiments of the present application, the terms "first", "second", and "third" are used only for the purpose of explanation, and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features limited to "first", "second", and "third" may explicitly or implicitly include at least one of the features. In the description of the present application, unless there is a clear and specific limitation, "a plurality" means at least two, for example, two, three, etc. Also, the terms "comprising", "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the indicated steps or units, and preferably may further include steps or units not shown, or preferably may further include other steps or units specific to these processes, methods, products or devices.

[0030] As used herein, "embodiment" means that a particular feature, structure or characteristic described in connection with an embodiment may be included in at least one embodiment of the present application. This phrase described at various places in this specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will understand, explicitly and implicitly, that the embodiments described in this specification may be combined with other embodiments.

[0031] For ease of understanding, the following explains the technical terms appearing in the present application.

[0032] A stator refers to the stationary part of a motor and is used to generate a rotating magnetic field.

[0033] A rotor refers to the rotating member of a motor and is used to realize the conversion between electrical energy and mechanical energy.

[0034] Pitch refers to the distance that two element edges of the same element in the motor winding span across the armature surface, and is usually represented by the number of stator slots formed in the stator core.

[0035] As shown in FIGS. 1 and 2, FIG. 1 is a schematic structural diagram of an embodiment of the stator of a flat wire motor according to the present application, and FIG. 2 is a schematic structural diagram of the stator core in the stator shown in FIG. 1. In one aspect of the present application, a flat wire motor including a rotor and a stator is provided, the rotor is provided in a space surrounded by the inner wall of the stator core of the stator, the number of slots per pole per phase of the flat wire motor may be 3, the number of poles of the rotor is an even number, and the combination of slots and poles of the flat wire motor may be 6 poles and 54 slots, 8 poles and 72 slots, 10 poles and 90 slots, 12 poles and 108 slots, etc., and in the present application, it is not specifically limited thereto.

[0036] As shown in FIG. 1, the stator of the flat wire motor includes a stator core 10 and a stator winding 20.

[0037] As shown in FIG. 2, a plurality of stator slots 11 are uniformly arranged along the circumferential direction on the inner wall of the stator core 10, the number of stator slots 11 is a multiple of 3, for example, the number of stator slots 11 may be 54 or 72, any one of the stator slots 11 extends in the axial direction of the stator core 10, penetrates the inner wall of the stator core 10 along the axial direction of the stator core 10, and the stator slots 11 are further divided into N layers along the radial direction of the stator core 10.

[0038] The stator winding 20 includes a three-phase winding sequentially and periodically arranged along the circumferential direction of the stator core 10. The three-phase winding is respectively a U-phase winding, a V-phase winding, and a W-phase winding. Each phase winding includes a plurality of parallel branch paths (hereinafter referred to as p parallel branch paths). The plurality of parallel branch paths are rotationally symmetric in the circumferential direction. For example, each phase winding includes three parallel branch paths, and the three parallel branch paths are rotationally symmetric in the circumferential direction of the stator core 10. Alternatively, each phase winding may include two or four parallel branch paths.

[0039] By limiting that the plurality of parallel branch paths in each phase winding are rotationally symmetric in the circumferential direction, the magnetic field distributions of the plurality of parallel branch paths in each phase winding are the same, and the potentials are balanced. Therefore, the circulating current generated between the parallel branch paths can be avoided, the additional AC copper loss at high frequencies can be significantly reduced, the efficiency of the flat wire motor during high-speed operation can be improved, local overheating of the winding can be avoided, and the service life of the flat wire motor can be extended.

[0040] In this embodiment, the stator is composed of a three-phase winding with a phase difference of 120 electrical degrees and the stator core 10. The structure of the stator winding 20 is in the stator core 10. Each phase winding includes three parallel branch paths. The three parallel branch paths use the central axis of the stator core 10 as the rotation axis, and the three parallel branch paths in the same-phase winding are rotationally symmetric. When the stator is applied to a flat wire motor, the central axis may refer to the rotor center line of the rotor in the flat wire motor. Rotational symmetry may mean that after a certain parallel branch path in the same-phase winding moves by a certain number of stator slots, it overlaps with other parallel branch paths in the same-phase winding.

[0041] As shown in FIG. 5, FIG. 5 is a schematic diagram of a circuit in which the parallel branch paths in each phase winding of the stator shown in FIG. 1 use a star connection. Each phase winding is composed of three parallel branch paths.

[0042] Optionally, as shown in FIG. 6, FIG. 6 is a schematic diagram of a circuit in which the parallel branch paths in each phase winding of the stator shown in FIG. 1 use a delta connection. Each phase winding is composed of three parallel branch paths.

[0043] As shown in FIGS. 1, 2, and 3, FIG. 3 is a schematic diagram of the structure of the hairpin coil in the stator shown in FIG. 1.

[0044] Each parallel branch path is connected by a connecting wire and includes a plurality of hairpin coils 21 with different pitches. In each stator slot 11, flat wire conductors of n layers of hairpin coils 21 are provided. n is a positive integer, that is, flat wire conductors are provided in each slot layer in the stator slot 11. The hairpin coil 21 is formed of a flat wire conductor, the cross-section of the flat wire conductor is rectangular, and it is inserted into the stator slot 11. Each hairpin coil 21 includes two linearly arranged parallel straight segments 211 and a connecting segment 212 connecting the two straight segments 211. The straight segment 211 is inserted into the stator slot 11, and the connecting segment 212 is provided outside the stator slot 11. The connecting segment 212 may be U-shaped or V-shaped. The pitch of the hairpin coil is the number of stator slots spanned by the two linearly arranged parallel straight segments 211 of the hairpin coil 21, and the welding pitch between the hairpin coils 21 is the number of stator slots spanned by the adjacent straight segments 211 of two adjacent hairpin coils 21.

[0045] The hairpin coil 21 further includes a bending segment 213 connected to the straight segment 211. The bending segment 213 is also provided outside the stator slot 11 and is provided on the end face of the stator core 10 together with the connecting segment 212. Between the adjacent bending segments 213 of the adjacent hairpin coils in the same parallel branch path, they are connected and electrically conducted by a connecting wire.

[0046] In one embodiment, after inserting the hairpin coil 21 into the status slot 11, the hairpin coil 21 can be bent to form a bent portion 223. After the hairpin coil 21 is inserted into the status slot 11, its connection segment 212 forms the wire insertion end of the stator winding 20, and the bent portion 223 forms the welding end of the stator winding 20.

[0047] Here, the bending direction of the hairpin coil may be provided to be bent to one side. In other embodiments, as shown in FIG. 4, the bending directions of the first bending segment 214 and the second bending segment 215 of some hairpin coils 21 are parallel, and are used for being wound with a direction change. As shown in FIG. 3, the bending directions of the first bending segment 214 and the second bending segment 215 of the remaining hairpin coils 21 are provided symmetrically and are used for being wound in the same direction.

[0048] In the present application, N layers of hairpin coils 21 are provided in each status slot 11. That is, two straight segments 211 of one hairpin coil 21 are provided in each slot layer of the status slot 11. The hairpin coils 21 of each parallel branch path are provided across N slot layers in different status slots 11. Thereby, the potential phase difference due to the positions in the status slots of the plurality of parallel branch paths of each phase winding can be eliminated. N is a positive integer and is 4 or more. For example, N may be 4, 5, 6, 7, 8, 9, or 10. For example, when N is 4, four layers of straight segments 211 are provided in each status slot 11.

[0049] The plurality of parallel branch paths of the same phase are all provided across n slot layers in different status slots, and the status slots 11 occupied by each phase winding are rotationally symmetric on the stator circumference. Thereby, the p branch paths of the same phase are completely symmetric, no circulating current is generated when the flat wire motor operates normally, the copper loss of the motor is reduced, and the motor efficiency is improved.

[0050] As shown in FIG. 7, FIG. 7 is a schematic diagram of the structure of the slot layer of the status slot in the stator core shown in FIG. 2. In one specific application scenario, N is 6. In each status slot 11, six layers of straight segments 211 are provided. That is, each status slot 11 contains four layers of flat wire conductors. Let the first layer be L1, the second layer be L2, the third layer be L3, the fourth layer be L4, the fifth layer be L5, and the sixth layer be L6. The first slot layer is the bottom layer of the status slot 11, and the sixth slot layer is the slot mouth layer. Or, the first slot layer is the slot mouth layer of the status slot 11, and the sixth slot layer is the bottom layer of the slot.

[0051] In one embodiment, since the hairpin coils 21 in the same status slot 11 are in the same phase, there is no need for phase insulation paper between the straight segments 211 of different layers in the same status slot 11, and the insulation cost of the flat wire motor can be reduced.

[0052] Here, when N = (2n + 1)×2, the combination of the total number of slot layers occupied by each parallel branch path in each status slot 11 is 2n, or 2n, 2n - 1, 2n - 2. When N = 2n×2, the combination of the total number of slot layers occupied by each parallel branch path in each status slot 11 is 2n, 2n - 1, or 2n, 2n - 1, 2n - 2. When N = 2n + 1, the combination of the total number of slot layers occupied by each parallel branch path in each status slot 11 is n, n - 1, or n, n - 1, n - 2. N is a positive integer and is 4 or more. Also, the total number of slot layers of each parallel branch path in each status slot 11 is also a positive integer.

[0053] For example, in the above application scenario, when the number of slot layers N of the status slot 11 is 4, the combination of the total number of slot layers occupied by each parallel branch path in each status slot 11 may be 2, 1. When the number of slot layers N of the status slot 11 is 6, the combination of the total number of slot layers occupied by each parallel branch path in each status slot 11 may be 2 or 2, 1. When the number of slot layers N of the status slot 11 is 7, the combination of the total number of slot layers occupied by each parallel branch path in each status slot 11 may be 3, 2 or 3, 2, 1.

[0054] By limiting the number of slot layers N in the status slot 11 and the total number of slot layers occupied by each corresponding parallel branch path in each status slot, the wire type of the hairpin coil 21 can be reduced, the manufacturing die of the flat wire motor can be reduced, the manufacturing cost can be reduced, and the processing and manufacturing efficiency can be effectively improved.

[0055] When the total number of slot layers occupied by each parallel branch path in the status slot 11 is 1, the position of the one slot layer is the first layer or the Nth layer of the status slot 11. When the total number of slot layers occupied by each parallel branch path in the status slot 11 is 2, the two slot layers are provided adjacent to each other in the status slot 11, or the two slot layers are the first layer and the Nth layer in the status slot 11 respectively. When the total number of slot layers occupied by each parallel branch path in the status slot 11 is 3, two of the three slot layers are provided adjacent to each other, and the position of the remaining one slot layer is the first layer or the Nth layer of the status slot 11, and is provided separated from the other two slot layers by four slot layers. When the total number of slot layers occupied by each parallel branch path in the status slot 11 is 4, the four slot layers are divided into two groups, each group is provided separated from the four slot layers, and each group includes two adjacent slot layers. By such limited means, the wire type of the hairpin coil 21 can be further reduced, that is, the number of manufacturing molds can be further reduced, the cost can be reduced, and the processing and manufacturing efficiency can be improved.

[0056] In one embodiment, the combinations of the pitches of the hairpin coils 21 in each parallel branch path are 8, 9, 11, 12, 16. In another embodiment, the pitch of the hairpin coil 21 in the same slot layer of each parallel branch path is 9. In still another embodiment, the pitch of the hairpin coil 21 in the first slot layer or the Nth slot layer of each parallel branch path is 8 or 8, 11. Here, the pitch of the hairpin coil 21 is the number of status slots spanned by the two straight segments 211 of the hairpin coil 21.

[0057] Here, the welding pitch between the hairpin coils 21 in each parallel branch path may all be 9 or 11, that is, the number of status slots spanned by the two adjacent straight segments 211 of the two adjacent hairpin coils 21 in the same parallel branch path is all 9 or 11.

[0058] In some embodiments, the in-line end of each parallel branch is located in the Nth slot layer of the status slot 11, the out-line end is located in the (N - 1)th slot layer of the status slot 11, or both the in-line end and the out-line end of each parallel branch are located in the first slot layer and the Nth slot layer of the status slot 11, so as to facilitate the extraction of the in-line end and the out-line end of the parallel branch. By concentrating the lead-out positions of the parallel branches, the space in the axial direction and the radial direction of the winding can be reduced, and the manufacturing difficulty of the flat wire motor can be reduced.

[0059] To facilitate understanding, hereinafter, with reference to specific application scenarios, the connection method of the parallel branches in the present application will be described in detail.

[0060] In one specific application scenario, taking a 6-pole 54-slot flat wire motor as an example, the number of status slots 11 in the stator core 10 is 54, the number of rotor poles is 6, the number of slots per pole per phase is 3, and the number of slot layers N in each status slot 11 is 4. The stator winding is divided into U phase, V phase and W phase, and the number of parallel branches provided in each phase winding is 3.

[0061] As shown in FIG. 8, FIG. 8 is a schematic diagram of the first winding of the U-phase winding in a 6-pole 54-slot flat wire motor according to the present application when the number of slot layers is 4, and FIG. 9 is a schematic diagram of the second winding of the U-phase winding in a 6-pole 54-slot flat wire motor according to the present application when the number of slot layers is 4. The solid line indicates the connection method of the wire insertion end, the dashed line indicates the connection method of the welding end, U1, U2, and U3 can be used as voltage lead-out wires or neutral point lead-out wires, and X1, X2, and X3 can be used as voltage lead-out wires or neutral point lead-out wires.

[0062] Hereinafter, as shown in FIGS. 8 and 9, the first parallel branch, the second parallel branch, and the third parallel branch of the U-phase winding in this embodiment will be described in detail respectively.

[0063] Here, i(j) represents the j-th slot layer of the i-th slot. For example, 1(1) represents the first slot layer of the first slot, and 10(2) represents the second slot layer of the tenth slot.

[0064] There are two types of winding methods for the first parallel branch, the second parallel branch, and the third parallel branch of the U-phase winding.

[0065] As shown in FIG. 8, in the first winding method, the slot numbers passed by the series connection of the first parallel branch of the U-phase winding are 1(1) → 10(2) → 21(1) → 30(2) → 38(1) → 47(2) → 2(3) → 11(4) → 19(3) → 28(4) → 39(3) → 48(4) → 2(4) → 47(3) → 39(4) → 30(3) → 19(4) → 10(3) → 1(2) → 46(1) → 38(2) → 29(1) → 21(2) → 12(1).

[0066] The slot numbers passed by the series connection of the second parallel branch of the U-phase winding are 2(1) → 11(2) → 19(1) → 28(2) → 39(1) → 48(2) → 3(3) → 12(4) → 20(3) → 29(4) → 37(3) → 46(4) → 3(4) → 48(3) → 37(4) → 28(3) → 20(4) → 11(3) → 2(2) → 47(1) → 39(2) → 30(1) → 19(2) → 10(1).

[0067] The slot numbers passed by the series connection of the third parallel branch of the U-phase winding are 3(1) → 12(2) → 20(1) → 29(2) → 37(1) → 46(2) → 1(3) → 10(4) → 21(3) → 30(4) → 38(3) → 47(4) → 1(4) → 46(3) → 38(4) → 29(3) → 21(4) → 12(3) → 3(2) → 48(1) → 37(2) → 28(1) → 20(2) → 11(1).

[0068] As shown in Fig. 9, in the second winding method, the slot numbers through which the series connection of the first parallel branch of the U-phase winding passes are: 1(1)→10(2)→19(3)→28(4)→39(3)→48(4)→2(3)→11(4)→2(4)→47(3)→39(4)→30(3)→19(4)→10(3)→1(2)→46(1)→38(2)→29(1)→21(2)→12(1)→21(1)→30(2)→38(1)→47(2).

[0069] The slot numbers through which the series connection of the second parallel branch of the U-phase winding passes are: 2(1)→11(2)→20(3)→29(4)→37(3)→46(4)→3(3)→12(4)→3(4)→48(3)→37(4)→28(3)→20(4)→11(3)→2(2)→47(1)→39(2)→30(1)→19(2)→10(1)→19(1)→28(2)→39(1)→48(2).

[0070] The slot numbers through which the series connection of the third parallel branch of the U-phase winding passes are: 3(1)→12(2)→21(3)→30(4)→38(3)→47(4)→1(3)→10(4)→1(4)→46(3)→38(4)→29(3)→21(4)→12(3)→3(2)→48(1)→37(2)→28(1)→20(2)→11(1)→20(1)→29(2)→37(1)→46(2).

[0071] The U-phase winding, V-phase winding, and W-phase winding are symmetrically and uniformly distributed on the circumference of the stator core 10. Here, the winding methods of the V-phase winding and W-phase winding are omitted.

[0072] In another application scenario, still taking the 6-pole 54-slot flat wire motor as an example, the number of stator slots 11 in the stator core 10 is 54, the number of rotor poles is 6, the number of slots per pole per phase is 3, and the number of slot layers N in each stator slot 11 is 5. The stator winding is divided into U-phase, V-phase, and W-phase, and the number of parallel branches provided in each phase winding is 3.

[0073] As shown in Fig. 10, Fig. 10 is a schematic winding diagram of the U-phase winding when the number of slot layers is 5 in a 6-pole 54-slot flat wire motor according to the present application.

[0074] As shown in Fig. 10, the slot numbers through which the series connection of the first parallel branch of the U-phase winding passes are 1(1) → 10(2) → 21(1) → 30(2) → 38(1) → 47(2) → 2(3) → 11(4) → 19(3) → 28(4) → 39(3) → 48(4) → 3(5) → 48(5) → 37(5) → 28(5) → 20(5) → 11(5) → 2(4) → 47(3) → 39(4) → 30(3) → 19(4) → 10(3) → 1(2) → 46(1) → 38(2) → 29(1) → 21(2) → 12(1).

[0075] The slot numbers through which the series connection of the second parallel branch of the U-phase winding passes are 2(1) → 11(2) → 19(1) → 28(2) → 39(1) → 48(2) → 3(3) → 12(4) → 20(3) → 29(4) → 37(3) → 46(4) → 1(5) → 46(5) → 38(5) → 29(5) → 21(5) → 12(5) → 3(4) → 48(3) → 37(4) → 28(3) → 20(4) → 11(3) → 2(2) → 47(1) → 39(2) → 30(1) → 19(2) → 10(1).

[0076] The slot numbers through which the series connection of the third parallel branch of the U-phase winding passes are 3(1) → 12(2) → 20(1) → 29(2) → 37(1) → 46(2) → 1(3) → 10(4) → 21(3) → 30(4) → 38(3) → 47(4) → 2(5) → 47(5) → 39(5) → 30(5) → 19(5) → 10(5) → 1(4) → 46(3) → 38(4) → 29(3) → 21(4) → 12(3) → 3(2) → 48(1) → 37(2) → 28(1) → 20(2) → 11(1).

[0077] In another application scenario, still taking the 6-pole 54-slot flat wire motor as an example, the number of stator slots 11 in the stator core 10 is 54, the number of rotor poles is 6, the number of slots per pole per phase is 3, and the number of slot layers N in each stator slot 11 is 6. The stator winding is divided into U phase, V phase and W phase, and the number of parallel branch paths provided in each phase winding is 3.

[0078] There are two winding methods for the first parallel branch path, the second parallel branch path and the third parallel branch path of the U-phase winding. As shown in FIGS. 11 and 12, FIG. 11 is a schematic diagram of the first winding method of the U-phase winding when the number of slot layers is 6 in the 6-pole 54-slot flat wire motor according to the present application, and FIG. 12 is a schematic diagram of the second winding method of the U-phase winding when the number of slot layers is 6 in the 6-pole 54-slot flat wire motor according to the present application.

[0079] As shown in FIG. 11, in the first winding method, the slot numbers passed by the series connection of the first parallel branch path of the U-phase winding are 1(1)→10(2)→21(1)→30(2)→38(1)→47(2)→2(3)→11(4)→19(3)→28(4)→39(3)→48(4)→3(5)→12(6)→20(5)→29(6)→37(5)→46(6)→3(6)→48(5)→37(6)→28(5)→20(6)→11(5)→2(4)→47(3)→39(4)→30(3)→19(4)→10(3)→1(2)→46(1)→38(2)→29(1)→21(2)→12(1).

[0080] The slot numbers passed by the series connection of the second parallel branch path of the U-phase winding are 2(1)→11(2)→19(1)→28(2)→39(1)→48(2)→3(3)→12(4)→20(3)→29(4)→37(3)→46(4)→1(5)→10(6)→21(5)→30(6)→38(5)→47(6)→1(6)→46(5)→38(6)→29(5)→21(6)→12(5)→3(4)→48(3)→37(4)→28(3)→20(4)→11(3)→2(2)→47(1)→39(2)→30(1)→19(2)→10(1).

[0081] The slot numbers through which the series connection of the third parallel branch of the U-phase winding passes are 3(1) → 12(2) → 20(1) → 29(2) → 37(1) → 46(2) → 1(3) → 10(4) → 21(3) → 30(4) → 38(3) → 47(4) → 2(5) → 11(6) → 19(5) → 28(6) → 39(5) → 48(6) → 2(6) → 47(5) → 39(6) → 30(5) → 19(6) → 10(5) → 1(4) → 46(3) → 38(4) → 29(3) → 21(4) → 12(3) → 3(2) → 48(1) → 37(2) → 28(1) → 20(2) → 11(1).

[0082] As shown in Fig. 11, in the second winding method, the slot numbers through which the series connection of the first parallel branch of the U-phase winding passes are 1(1) → 10(2) → 19(3) → 28(4) → 39(3) → 48(4) → 2(3) → 11(4) → 20(5) → 29(6) → 37(5) → 46(6) → 3(5) → 12(6) → 3(6) → 48(5) → 37(6) → 28(5) → 20(6) → 11(5) → 2(4) → 47(3) → 39(4) → 30(3) → 19(4) → 10(3) → 1(2) → 46(1) → 38(2) → 29(1) → 21(2) → 12(1) → 21(1) → 30(2) → 38(1) → 47(2).

[0083] The slot numbers through which the series connection of the second parallel branch of the U-phase winding passes are 2(1) → 11(2) → 20(3) → 29(4) → 37(3) → 46(4) → 3(3) → 12(4) → 21(5) → 30(6) → 38(5) → 47(6) → 1(5) → 10(6) → 1(6) → 46(5) → 38(6) → 29(5) → 21(6) → 12(5) → 3(4) → 48(3) → 37(4) → 28(3) → 20(4) → 11(3) → 2(2) → 47(1) → 39(2) → 30(1) → 19(2) → 10(1) → 19(1) → 28(2) → 39(1) → 48(2).

[0084] The slot numbers through which the series connection of the third parallel branch of the U-phase winding passes are 3(1) → 12(2) → 21(3) → 30(4) → 38(3) → 47(4) → 1(3) → 10(4) → 19(5) → 28(6) → 39(5) → 48(6) → 2(5) → 11(6) → 2(6) → 47(5) → 39(6) → 30(5) → 19(6) → 10(5) → 1(4) → 46(3) → 38(4) → 29(3) → 21(4) → 12(3) → 3(2) → 48(1) → 37(2) → 28(1) → 20(2) → 11(1) → 20(1) → 29(2) → 37(1) → 46(2).

[0085] In another application scenario, still taking the 6-pole 54-slot flat wire motor as an example, the number of stator slots 11 in the stator core 10 is 54, the number of rotor poles is 6, the number of slots per pole per phase is 3, and the number of slot layers N in each stator slot 11 is 7. The stator winding is divided into U-phase, V-phase and W-phase, and the number of parallel branches provided in each phase winding is 3 for all.

[0086] As shown in FIG. 13, FIG. 13 is a schematic winding diagram of the U-phase winding when the number of slot layers is 7 in the 6-pole 54-slot flat wire motor according to the present application.

[0087] As shown in FIG. 13, the slot numbers through which the series connection of the first parallel branch of the U-phase winding passes are 1(1) → 10(2) → 21(1) → 30(2) → 38(1) → 47(2) → 2(3) → 11(4) → 19(3) → 28(4) → 39(3) → 48(4) → 3(5) → 12(6) → 20(5) → 29(6) → 37(5) → 46(6) → 1(7) → 46(7) → 38(7) → 29(7) → 21(7) → 12(7) → 3(6) → 48(5) → 37(6) → 28(5) → 20(6) → 11(5) → 2(4) → 47(3) → 39(4) → 30(3) → 19(4) → 10(3) → 1(2) → 46(1) → 38(2) → 29(1) → 21(2) → 12(1).

[0088] The slot numbers through which the series connection of the second parallel branch of the U-phase winding passes are 2(1) → 11(2) → 19(1) → 28(2) → 39(1) → 48(2) → 3(3) → 12(4) → 20(3) → 29(4) → 37(3) → 46(4) → 1(5) → 10(6) → 21(5) → 30(6) → 38(5) → 47(6) → 2(7) → 47(7) → 39(7) → 39(7) → 30(7) → 19(7) → 10(7) → 1(6) → 46(5) → 38(6) → 29(5) → 21(6) → 12(5) → 3(4) → 48(3) → 37(4) → 28(3) → 20(4) → 11(3) → 2(2) → 47(1) → 39(2) → 30(1) → 19(2) → 10(1).

[0089] The slot numbers through which the series connection of the third parallel branch of the U-phase winding passes are 3(1) → 12(2) → 20(1) → 29(2) → 37(1) → 46(2) → 1(3) → 10(4) → 21(3) → 30(4) → 38(3) → 47(4) → 2(5) → 11(6) → 19(5) → 28(6) → 39(5) → 48(6) → 3(7) → 48(7) → 37(7) → 28(7) → 20(7) → 11(7) → 2(6) → 47(5) → 39(6) → 30(5) → 19(6) → 10(5) → 1(4) → 46(3) → 38(4) → 29(3) → 21(4) → 12(3) → 3(2) → 48(1) → 37(2) → 28(1) → 20(2) → 11(1).

[0090] In another application scenario, still taking the 6-pole 54-slot flat wire motor as an example, the number of stator slots 11 in the stator core 10 is 54, the number of rotor poles is 6, the number of slots per pole per phase is 3, and the number of slot layers N in each stator slot 11 is 8. The stator winding is divided into U-phase, V-phase, and W-phase, and the number of parallel branches provided in each phase winding is 3.

[0091] As shown in FIG. 14, FIG. 14 is a schematic winding diagram of the U-phase winding when the number of slot layers is 8 in the 6-pole 54-slot flat wire motor according to the present application.

[0092] As shown in Fig. 14, the slot numbers through which the series connection of the first parallel branch of the U-phase winding passes are 1(1)→10(2)→21(1)→30(2)→38(1)→47(2)→2(3)→11(4)→19(3)→28(4)→39(3)→48(4)→3(5)→12(6)→20(5)→29(6)→37(5)→46(6)→1(7)→10(8)→21(7)→30(8)→38(7)→47(8)→1(8)→46(7)→38(8)→29(7)→21(8)→12(7)→3(6)→48(5)→37(6)→28(5)→20(6)→11(5)→2(4)→47(3)→39(4)→30(3)→19(4)→10(3)→1(2)→46(1)→38(2)→29(1)→21(2)→12(1).

[0093] The slot numbers through which the series connection of the second parallel branch of the U-phase winding passes are 2(1)→11(2)→19(1)→28(2)→39(1)→48(2)→3(3)→12(4)→20(3)→29(4)→37(3)→46(4)→1(5)→10(6)→21(5)→30(6)→38(5)→47(6)→2(7)→11(8)→19(7)→28(8)→39(7)→48(8)→2(8)→47(7)→39(8)→30(7)→19(8)→10(7)→1(6)→46(5)→38(6)→29(5)→21(6)→12(5)→3(4)→48(3)→37(4)→28(3)→20(4)→11(3)→2(2)→47(1)→39(2)→30(1)→19(2)→10(1).

[0094] The slot numbers through which the series connection of the third parallel branch of the U-phase winding passes are 3(1) → 12(2) → 20(1) → 29(2) → 37(1) → 46(2) → 1(3) → 10(4) → 21(3) → 30(4) → 38(3) → 47(4) → 2(5) → 11(6) → 19(5) → 28(6) → 39(5) → 48(6) → 3(7) → 12(8) → 20(7) → 29(8) → 37(7) → 46(8) → 3(8) → 48(7) → 37(8) → 28(7) → 20(8) → 11(7) → 2(6) → 47(5) → 39(6) → 30(5) → 19(6) → 10(5) → 1(4) → 46(3) → 38(4) → 29(3) → 21(4) → 12(3) → 3(2) → 48(1) → 37(2) → 28(1) → 20(2) → 11(1).

[0095] In another application scenario, still taking the 6-pole 54-slot flat wire motor as an example, the number of stator slots 11 in the stator core 10 is 54, the number of rotor poles is 6, the number of slots per pole per phase is 3, and the number of slot layers N in each stator slot 11 is 9. The stator winding is divided into U-phase, V-phase and W-phase, and the number of parallel branches provided in each phase winding is 3 for all.

[0096] As shown in Fig. 15, Fig. 15 is a schematic winding diagram of the U-phase winding when the number of slot layers is 9 in the 6-pole 54-slot flat wire motor according to the present application.

[0097] As shown in Fig. 15, the slot numbers through which the series connection of the first parallel branch of the U-phase winding passes are 1(1)→10(2)→21(1)→30(2)→38(1)→47(2)→2(3)→11(4)→19(3)→28(4)→39(3)→48(4)→3(5)→12(6)→20(5)→29(6)→37(5)→46(6)→1(7)→10(8)→21(7)→30(8)→38(7)→47(8)→2(9)→47(9)→39(9)→30(9)→19(9)→10(9)→1(8)→46(7)→38(8)→29(7)→21(8)→12(7)→3(6)→48(5)→37(6)→28(5)→20(6)→11(5)→2(4)→47(3)→39(4)→30(3)→19(4)→10(3)→1(2)→46(1)→38(2)→29(1)→21(2)→12(1).

[0098] The slot numbers through which the series connection of the second parallel branch of the U-phase winding passes are 2(1)→11(2)→19(1)→28(2)→39(1)→48(2)→3(3)→12(4)→20(3)→29(4)→37(3)→46(4)→1(5)→10(6)→21(5)→30(6)→38(5)→47(6)→2(7)→11(8)→19(7)→26(8)→39(7)→48(8)→3(9)→46(9)→37(9)→28(9)→20(9)→11(9)→2(8)→47(7)→39(8)→30(7)→19(8)→10(7)→1(6)→46(5)→38(6)→29(5)→21(6)→12(5)→3(4)→48(3)→37(4)→28(3)→20(4)→11(3)→2(2)→47(1)→39(2)→30(1)→19(2)→10(1).

[0099] The slot numbers through which the series connection of the third parallel branch of the U-phase winding passes are 3(1) → 12(2) → 20(1) → 29(2) → 37(1) → 46(2) → 1(3) → 10(4) → 21(3) → 30(4) → 38(3) → 47(4) → 2(5) → 11(6) → 19(5) → 28(6) → 39(5) → 48(6) → 3(7) → 12(8) → 20(7) → 29(8) → 37(7) → 46(8) → 1(9) → 46(9) → 38(9) → 29(9) → 21(9) → 12(9) → 3(8) → 48(7) → 37(8) → 28(7) → 20(8) → 11(7) → 2(6) → 47(5) → 39(6) → 30(5) → 19(6) → 10(5) → 1(4) → 46(3) → 38(4) → 29(3) → 21(4) → 12(3) → 3(2) → 48(1) → 37(2) → 28(1) → 20(2) → 11(1).

[0100] In another application scenario, still taking the 6-pole 54-slot flat wire motor as an example, the number of stator slots 11 in the stator core 10 is 54, the number of rotor poles is 6, the number of slots per pole per phase is 3, and the number of slot layers N in each stator slot 11 is 10. The stator winding is divided into U-phase, V-phase and W-phase, and the number of parallel branches provided in each phase winding is 3 for all.

[0101] As shown in Fig. 16, Fig. 16 is a schematic winding diagram of the U-phase winding when the number of slot layers is 10 in the 6-pole 54-slot flat wire motor according to the present application.

[0102] As shown in Fig. 16, the slot numbers through which the series connection of the first parallel branch of the U-phase winding passes are: 1(1)→10(2)→21(1)→30(2)→38(1)→47(2)→2(3)→11(4)→19(3)→28(4)→39(3)→48(4)→3(5)→12(6)→20(5)→29(6)→37(5)→46(6)→1(7)→10(8)→21(7)→30(8)→38(7)→47(8)→2(9)→11(10)→19(9)→28(10)→39(9)→48(10)→2(10)→47(9)→39(10)→30(9)→19(10)→10(9)→1(8)→46(7)→38(8)→29(7)→21(8)→12(7)→3(6)→48(5)→37(6)→28(5)→20(6)→11(5)→2(4)→47(3)→39(4)→30(3)→19(4)→10(3)→1(2)→46(1)→38(2)→28(1)→21(2)→12(1).

[0103] The slot numbers through which the series connection of the second parallel branch of the U-phase winding passes are: 2(1)→11(2)→19(1)→28(2)→39(1)→48(2)→3(3)→12(4)→20(3)→29(4)→37(3)→46(4)→1(5)→10(6)→21(5)→30(6)→38(5)→47(6)→2(7)→11(8)→19(7)→26(8)→39(7)→48(8)→3(9)→12(10)→20(9)→29(10)→37(9)→46(10)→3(10)→48(9)→37(10)→28(9)→20(10)→11(9)→2(8)→47(7)→39(8)→30(7)→19(8)→10(7)→1(6)→46(5)→38(6)→29(5)→21(6)→12(5)→3(4)→48(3)→37(4)→28(3)→20(4)→11(3)→2(2)→47(1)→39(2)→30(1)→19(2)→10(1).

[0104] The slot numbers through which the series connection of the third parallel branch of the U-phase winding passes are 3(1) → 12(2) → 20(1) → 29(2) → 37(1) → 46(2) → 1(3) → 10(4) → 21(3) → 30(4) → 38(3) → 47(4) → 2(5) → 11(6) → 19(5) → 28(6) → 39(5) → 48(6) → 3(7) → 12(8) → 20(7) → 29(8) → 37(7) → 46(8) → 1(9) → 10(10) → 21(9) → 30(10) → 36(9) → 47(10) → 1(10) → 46(9) → 38(10) → 29(9) → 21(10) → 12(9) → 3(8) → 48(7) → 37(8) → 28(7) → 20(8) → 11(7) → 2(6) → 47(5) → 39(6) → 30(5) → 19(6) → 10(5) → 1(4) → 46(3) → 38(4) → 29(3) → 21(4) → 12(3) → 3(2) → 48(1) → 37(2) → 28(1) → 20(2) → 11(1).

[0105] Referring to FIG. 3 and FIG. 4 together, the plurality of hairpin coils 21 of each parallel branch according to the present application include a long-pitch hairpin coil with a pitch of s / (2p) + a, a full-pitch hairpin coil with a pitch of s / (2p), and a short-pitch hairpin coil with a pitch of s / (2p) + a - 4, where a is an integer of 2 or more and 4 or less.

[0106] In each parallel branch, the first leg 211 and the second leg 212 of the short-pitch hairpin coil are respectively located in the k-th slot layer and the (k + 1)-th slot layer, the first leg 211 and the second leg 212 of the long-pitch hairpin coil are respectively located in the (k + 1)-th slot layer and the (k + 2)-th slot layer, the first leg 211 and the second leg 212 of the full-pitch hairpin coil are both distributed in the first slot layer or the n-th slot layer, and k is an odd number of 1 or more and n or less.

[0107] The voltage leads of the p parallel branches of each phase winding are located within s status slots and are located in the same slot layer or adjacent slot layers of different status slots. The neutral point leads of the p parallel branches of each phase winding are located within s status slots and are located in the same slot layer or adjacent slot layers of different status slots, thereby simplifying the structure of the winding.

[0108] All leads and neutral points of the three-phase winding are intensively distributed in the same slot layer or adjacent slot layers of different status slots 11. By concentrating the positions of the leads and neutral points of the parallel branches, the space in the axial and radial directions of the winding can be reduced, and the manufacturing difficulty of the flat wire motor can be reduced.

[0109] Since the p parallel branches of each phase winding are rotationally symmetric in the circumferential direction of the stator core 10, the voltage leads of the p parallel branches in the same phase winding are also rotationally symmetric in the circumferential direction of the stator core 10, and the neutral point leads of the p parallel branches in the same phase winding are also rotationally symmetric in the circumferential direction of the stator core 10. Furthermore, both the voltage leads and the neutral point leads are located in the same slot layer. For example, both the voltage leads and the neutral point leads are located in the first slot layer or the nth slot layer.

[0110] In this embodiment, in each phase winding, since the voltage leads and the neutral points of the p parallel branches are both rotationally symmetric along the circumferential direction of the stator core 10, the generation of circulating current can be avoided.

[0111] In one embodiment, the welding pitch between the hairpin coils 21 in each parallel branch may all be s / (2p), that is, the welding pitch between the hairpin coils 21 is the same as the pitch of the full-pitch hairpin coils. In one embodiment, the welding pitch between the hairpin coils 21 in the parallel branch may not be equal to the pitch of the full-pitch hairpin coils.

[0112] In one embodiment, a = 3, the pitch of the long-pitch hairpin coil is s / (2p) + 3, the pitch of the full-pitch hairpin coil is s / (2p), and the pitch of the short-pitch hairpin coil is s / (2p) - 1. In each parallel branch path, the hairpin coils of these three pitches exist simultaneously, and the hairpin coils of each parallel branch path are provided across n slot layers in different stator slots 11, thereby eliminating the potential phase difference due to the positions of the slot layers of p parallel branch paths.

[0113] In the above application scenario, the pitch of the short-pitch hairpin coil may be 11, the pitch of the full-pitch hairpin coil may be 12, and the pitch of the long-pitch hairpin coil may be 15.

[0114] In the above application scenario, when k = 1, the hairpin coil used between the first slot layer and the second slot layer of the parallel branch path is a short-pitch hairpin coil, and the hairpin coil used between the second slot layer and the third slot layer of the parallel branch path is a long-pitch hairpin coil. Similarly, the hairpin coil used between the third slot layer and the fourth slot layer of the parallel branch path is a short-pitch hairpin coil, and the hairpin coil used between the fourth slot layer and the fifth slot layer of the parallel branch path is a long-pitch hairpin coil. Without repeating the description, when the full-pitch hairpin coils are provided in the same slot layer, they are provided only in the first slot layer or the nth slot layer. Here, the winding method of each phase winding may be wave winding or lap winding.

[0115] As shown in FIGS. 17 to 19, FIG. 17 is a schematic winding diagram of the first parallel branch path of the U-phase winding in a 6-pole 72-slot flat wire motor according to the present application, where the number of slot layers is 4 and a is 3. FIG. 18 is a schematic winding diagram of the second parallel branch path of the U-phase winding in the flat wire motor shown in FIG. 17. FIG. 19 is a schematic winding diagram of the third parallel branch path of the U-phase winding in the flat wire motor shown in FIG. 17.

[0116] In the figure, the solid line indicates the wiring method of the wire insertion end, the dashed line indicates the wiring method of the welding end, U1, U2, and U3 can be either voltage lead-out wires or neutral point lead-out wires, and X1, X2, and X3 can be either voltage lead-out wires or neutral point lead-out wires.

[0117] In the above application scenario, m = 3, the number of status slots s = 72, the number of pole pairs of the rotor p = 3, the number of slots per pole per phase q = 4, the number of slot layers n of status slot 11 = 4, the pitch of the long-pitch hairpin coil is 15, the pitch of the full-pitch hairpin coil is 12, the pitch of the short-pitch hairpin coil is 11, and when the welding pitch between adjacent hairpin coils in the parallel branch is 12, the hairpin coil used between the first slot layer and the second slot layer of the parallel branch is a short-pitch hairpin coil, the hairpin coil used between the second slot layer and the third slot layer of the parallel branch is a long-pitch hairpin coil, the hairpin coil used between the third slot layer and the fourth slot layer of the parallel branch is a short-pitch hairpin coil, the full-pitch hairpin coils are provided in the same slot layer and only provided in the first slot layer or the fourth slot layer. Thus, the stator winding 20 of this embodiment only requires five types of hairpin coils 21, and the stator winding 20 of this embodiment is composed of three-phase windings with electrical angles of 120 degrees different in phase.

[0118] Hereinafter, with reference to FIGS. 17, 18, and 19, the first parallel branch, the second parallel branch, and the third parallel branch of the U-phase winding in this embodiment will be described in detail respectively.

[0119] Here, the number i(j) indicates the j-th slot layer of the i-th slot. For example, 1(1) indicates the first slot layer of the first slot, and 7(2) indicates the second slot layer of the seventh slot.

[0120] As shown in Fig. 17, the first parallel branch of the U-phase winding is drawn in from the voltage lead-out position U1 and drawn out from the neutral point lead-out position X1. The slot numbers through which the series connection of the first parallel branch passes are 1(1)→13(2)→24(1)→36(2)→47(1)→59(2)→70(1)→10(2)→25(3)→37(4)→48(3)→60(4)→71(3)→11(4)→22(3)→34(4)→22(4)→10(3)→71(4)→59(3)→48(4)→36(3)→25(4)→13(3)→70(2)→58(1)→47(2)→35(1)→24(2)→12(1)→1(2)→61(1).

[0121] As shown in Fig. 18, the second parallel branch of the U-phase winding is drawn in from the voltage lead-out position U2 and drawn out from the neutral point lead-out position X2. The slot numbers through which the series connection of the second parallel branch passes are 71(1)→11(2)→22(1)→34(2)→49(3)→61(4)→72(3)→12(4)→23(3)→35(4)→46(3)→58(4)→46(4)→34(3)→23(4)→11(3)→72(4)→60(3)→49(4)→37(3)→22(2)→10(1)→71(2)→59(1)→48(2)→36(1)→25(2)→13(1)→25(1)→37(2)→48(1)→60(2).

[0122] As shown in Fig. 19, the third parallel branch of the U-phase winding is drawn in from the voltage lead-out position U3 and drawn out from the neutral point lead-out position X3. The slot numbers through which the series connection of the third parallel branch passes are 72(1)→12(2)→23(1)→35(2)→46(1)→58(2)→1(3)→13(4)→24(3)→36(4)→47(3)→59(4)→70(3)→10(4)→70(4)→58(3)→47(4)→35(3)→24(4)→12(3)→1(4)→61(3)→46(2)→34(1)→23(2)→11(1)→72(2)→60(1)→49(2)→37(1)→49(1)→61(2).

[0123] The number distribution of the start slots and end slots corresponding to the three parallel branch paths in the U-phase winding is such that U1 corresponds to 1(1), X1 corresponds to 61(1), U2 corresponds to 71(1), X2 corresponds to 60(2), U3 corresponds to 72(1), and X3 corresponds to 61(2). U1, U2, and U3 are connected in parallel, X1, X2, and X3 are connected in parallel, and finally connected by a bus bar to form the completed U-phase winding.

[0124] The U-phase winding, V-phase winding, and W-phase winding are symmetrically and uniformly distributed on the circumference of the stator core 10. In this embodiment, the V-phase winding and W-phase winding are obtained by rotating the U-phase winding by a plurality of stator slots 11 along the circumferential direction of the stator core 10. Here, the winding method of the V-phase winding and W-phase winding is omitted.

[0125] Based on the above application scenario, that is, m = 3, the number of stator slots s = 72, the number of rotor pole pairs p = 3, and the number of slots per pole per phase q = 4, the number of slot layers n of the stator slot 11 is 6, the pitch of the long-pitch hairpin coil is 15, the pitch of the full-pitch hairpin coil is 12, the pitch of the short-pitch hairpin coil is 11, and the welding pitch between adjacent hairpin coils in the parallel branch path is 12. When this is the case, the hairpin coil used between the first slot layer and the second slot layer of the parallel branch path is a short-pitch hairpin coil, the hairpin coil used between the second slot layer and the third slot layer of the parallel branch path is a long-pitch hairpin coil, the hairpin coil used between the third slot layer and the fourth slot layer of the parallel branch path is a short-pitch hairpin coil, the hairpin coil used between the fourth slot layer and the fifth slot layer of the parallel branch path is a long-pitch hairpin coil, the hairpin coil used between the fifth slot layer and the sixth slot layer of the parallel branch path is a short-pitch hairpin coil, and the full-pitch hairpin coil is provided in the same slot layer and only provided in the first slot layer or the sixth slot layer. Thus, the stator winding 20 of this embodiment only requires seven types of hairpin coils 21. The stator winding 20 of this embodiment consists of three-phase windings with a phase difference of 120 electrical degrees.

[0126] As shown in FIG. 20, the first parallel branch of the U-phase winding is drawn in from the voltage lead position U1, drawn out from the neutral point lead position X1, and the slot numbers through which the series connection of the first parallel branch passes are 1(1)→13(2)→24(1)→36(2)→47(1)→59(2)→70(1)→10(2)→25(3)→37(4)→48(3)→60(4)→71(3)→11(4)→22(3)→34(4)→49(5)→61(6)→72(5)→12(6)→23(5)→35(6)→46(5)→58(6)→46(6)→34(5)→23(6)→11(5)→72(6)→60(5)→49(6)→37(5)→22(4)→10(3)→71(4)→59(3)→48(4)→36(3)→25(4)→13(3)→70(2)→58(1)→47(2)→35(1)→24(2)→12(1)→1(2)→61(1).

[0127] As shown in FIG. 21, the second parallel branch of the U-phase winding is drawn in from the voltage lead position U2, drawn out from the neutral point lead position X2, and the slot numbers through which the series connection of the second parallel branch passes are 71(1)→11(2)→22(1)→34(2)→49(3)→61(4)→72(3)→12(4)→23(3)→35(4)→46(3)→58(4)→1(5)→13(6)→24(5)→36(6)→47(5)→59(6)→70(5)→10(6)→70(6)→58(5)→47(6)→35(5)→24(6)→12(5)→1(6)→61(5)→46(4)→34(3)→23(4)→11(3)→72(4)→60(3)→49(4)→37(3)→22(2)→10(1)→71(2)→59(1)→36(1)→25(2)→13(1)→25(1)→37(2)→48(1)→60(2).

[0128] As shown in FIG. 22, the third parallel branch of the U-phase winding is drawn in from the voltage lead position U3, drawn out from the neutral point lead position X3, and the slot numbers through which the series connection of the third parallel branch passes are (1)→12(2)→23(1)→35(2)→46(1)→58(2)→1(3)→13(4)→24(3)→36(4)→47(3)→59(4)→70(3)→10(4)→25(5)→37(6)→48(5)→60(6)→71(5)→11(6)→22(5)→34(6)→22(6)→10(5)→71(6)→59(5)→48(6)→36(5)→25(6)→13(5)→70(4)→58(3)→47(4)→35(3)→24(4)→12(3)→1(4)→61(3)→46(2)→34(1)→23(2)→11(1)→72(2)→60(1)→49(2)→37(1)→49(1)→61(2).

[0129] The number distributions of the start slots and end slots corresponding to the three parallel branches in the U-phase winding are such that U1 corresponds to 1(1), X1 corresponds to 61(1), U2 corresponds to 71(1), X2 corresponds to 60(2), U3 corresponds to 72(1), and X3 corresponds to 61(2). U1, U2, and U3 are connected in parallel, X1, X2, and X3 are connected in parallel, and finally they are connected by a bus bar to form the completed U-phase winding.

[0130] Based on the above application scenario, that is, m = 3, the number of stator slots s = 72, the number of rotor pole pairs p = 3, and the number of slots per pole per phase q = 4, when the number of slot layers n = 8 of stator slot 11, the pitch of the long-pitch hairpin coil is 15, the pitch of the full-pitch hairpin coil is 12, and the pitch of the short-pitch hairpin coil is 11. Thus, the stator winding 20 of this embodiment only requires 9 types of hairpin coils 21.

[0131] As shown in Fig. 23, the first parallel branch of the U-phase winding is drawn in from the voltage lead position U1, drawn out from the neutral point lead position X1, and the slot numbers through which the series connection of the first parallel branch passes are 1(1)→13(2)→24(1)→36(2)→47(1)→59(2)→70(1)→10(2)→25(3)→37(4)→48(3)→60(4)→71(3)→11(4)→22(3)→34(4)→49(5)→61(6)→72(5)→12(6)→23(5)→35(6)→46(5)→58(6)→1(7)→13(8)→24(7)→36(8)→47(7)→59(8)→70(7)→10(8)→70(8)→58(7)→47(8)→35(7)→24(8)→12(7)→1(8)→61(7)→46(6)→34(5)→23(6)→11(5)→72(6)→60(5)→49(6)→37(5)→22(4)→10(3)→71(4)→59(3)→48(4)→36(3)→25(4)→13(3)→70(2)→58(1)→47(2)→35(1)→24(2)→12(1)→1(2)→61(1).

[0132] As shown in Fig. 24, the second parallel branch of the U-phase winding is drawn in from the voltage lead position U2, drawn out from the neutral point lead position X2, and the slot numbers through which the series connection of the second parallel branch passes are 71(1)→11(2)→22(1)→34(2)→49(3)→61(4)→72(3)→12(4)→23(3)→35(4)→46(3)→58(4)→1(5)→13(6)→24(5)→36(6)→47(5)→59(6)→70(5)→10(6)→25(7)→37(8)→48(7)→60(8)→71(7)→11(8)→22(7)→34(8)→22(8)→10(7)→71(8)→59(7)→48(8)→36(7)→25(8)→13(7)→70(6)→58(5)→47(6)→35(5)→24(6)→12(5)→1(6)→61(5)→46(4)→34(3)→23(4)→11(3)→72(4)→60(3)→49(4)→37(3)→22(2)→10(1)→71(2)→59(1)→36(1)→25(2)→13(1)→25(1)→37(2)→48(1)→60(2).

[0133] As shown in Fig. 25, the third parallel branch of the U-phase winding is drawn in from the voltage lead-out position U3, drawn out from the neutral point lead-out position X3, and the slot numbers through which the series connection of the third parallel branch passes are 72(1) → 12(2) → 23(1) → 35(2) → 46(1) → 58(2) → 1(3) → 13(4) → 24(3) → 36(4) → 47(3) → 59(4) → 70(3) → 10(4) → 25(5) → 37(6) → 48(5) → 60(6) → 71(5) → 11(6) → 22(5) → 34(6) → 49(7) → 61(8) → 72(7) → 12(8) → 23(7) → 35(8) → 46(7) → 58(8) → 46(8) → 34(7) → 23(8) → 11(7) → 72(8) → 60(7) → 49(8) → 37(7) → 22(6) → 10(5) → 71(6) → 59(5) → 48(6) → 36(5) → 25(6) → 13(5) → 70(4) → 58(3) → 47(4) → 35(3) → 24(4) → 12(3) → 1(4) → 61(3) → 46(2) → 34(1) → 23(2) → 11(1) → 72(2) → 60(1) → 49(2) → 37(1) → 49(1) → 61(2).

[0134] For the number distribution of the start slot and the end slot corresponding to the three parallel branches in the U-phase winding, U1 corresponds to 1(1), X1 corresponds to 61(1), U2 corresponds to 71(1), X2 corresponds to 60(2), U3 corresponds to 72(1), and X3 corresponds to 61(2). U1, U2, and U3 are connected in parallel, X1, X2, and X3 are connected in parallel, and finally connected by a bus bar to form the completed U-phase winding.

[0135] In another application scenario, when a = 4, the pitch of the long-pitch hairpin coil is s / (2p) + 4, the pitch of the full-pitch hairpin coil is s / (2p), and the pitch of the short-pitch hairpin coil is also s / (2p). That is, the short-pitch hairpin coil is also regarded as a full-pitch hairpin coil, and the first leg 211 and the second leg 212 of the short-pitch hairpin coil (full-pitch hairpin coil) are located in the k-th slot layer and the k + 1-th slot layer, respectively.

[0136] In the above application scenario, the number of status slots s = 6pq, the number of slot layers n in status slot 11 is an even number, and a = 4. Therefore, in this embodiment, the short-pitch hairpin coil is changed to a full-pitch hairpin coil. As shown in FIG. 26, in the phase belt distribution of the three-phase winding, the polarity distribution of each odd layer is the same, the polarity distribution of each even layer is the same, and with respect to the polarity distribution of the odd layer, it is shifted by one status slot.

[0137] In the present invention, the hairpin coils of the parallel branch paths in each phase winding are all provided across n slot layers in different status slots 11. The winding method of the winding may be wave winding or lap winding. After a certain parallel branch path in the same-phase winding moves by a certain number of status slots 11, it overlaps with other parallel branch paths in the winding. By using only two types of hairpin coils, namely long-pitch hairpin coils and full-pitch hairpin coils, the types of hairpin coils that need to be used are significantly reduced, the number of molds that need to be manufactured is reduced, the cost is reduced, and the processing and manufacturing efficiency is improved. At the same time, regarding the phase belt distribution of the three-phase winding, the positions of q adjacent slots with the same polarity in the parallel branch paths of the same-phase winding are shifted by one slot to the adjacent pole, and the equivalent pitch of a certain phase is made smaller than the full-pitch pitch, realizing the effect of short pitch winding, reducing the back electromotive force harmonics of the flat wire motor, improving the efficiency of the flat wire motor, and optimizing the NVH of the vehicle, that is, noise, vibration, and harshness.

[0138] In the above application scenario, the number of slot layers n of the status slot 11 may be an even number such as 2, 4, 6, 8, 10, etc. Each phase winding includes three parallel branch paths. The combination of the pitches of the hairpin coils 21 in each parallel branch path is 12 and 16. That is, the pitch of the long-pitch hairpin coil is 16, and the pitch of the full-pitch hairpin coil is 12. The welding pitch between the hairpin coils in each parallel branch path is all 11.

[0139] In another application scenario, taking a 6-pole 72-slot motor as an example, m = 3, the number of stator slots s = 72, the number of rotor pole pairs p = 3, the number of slots per pole per phase q = 4, the number of slot layers n of stator slot 11 is 4, the pitch of the long pitch hairpin coil is 16, and the pitch of the full pitch hairpin coil is 12.

[0140] In the above application scenario, when using the first winding method, the stator winding 20 only requires 5 types of hairpin coils.

[0141] As shown in FIG. 27, the first parallel branch of the U-phase winding is introduced from the voltage lead-out position U1 and drawn out from the neutral point lead-out position X1. The slot numbers passed by the series connection of the first parallel branch are 1(1)→12(2)→24(1)→35(2)→47(1)→58(2)→70(1)→9(2)→25(3)→36(4)→48(3)→59(4)→71(3)→10(4)→22(3)→33(4)→21(4)→10(3)→70(4)→59(3)→47(4)→36(3)→24(4)→13(3)→69(2)→58(1)→46(2)→35(1)→23(2)→12(1)→72(2)→61(1).

[0142] As shown in FIG. 28, the second parallel branch of the U-phase winding is introduced from the voltage lead-out position U2 and drawn out from the neutral point lead-out position X2. The slot numbers passed by the series connection of the second parallel branch are 71(1)→10(2)→22(1)→33(2)→49(3)→60(4)→72(3)→11(4)→23(3)→34(4)→46(3)→57(4)→45(4)→34(3)→22(4)→11(3)→71(4)→60(3)→48(4)→37(3)→21(2)→10(1)→70(2)→59(1)→47(2)→36(1)→24(2)→13(1)→25(1)→36(2)→48(1)→59(2).

[0143] As shown in Fig. 29, the third parallel branch of the U-phase winding is drawn in from the voltage lead-out position U3 and drawn out from the neutral point lead-out position X3. The slot numbers through which the series connection of the third parallel branch passes are 72(1) → 11(2) → 23(1) → 34(2) → 46(1) → 57(2) → 1(3) → 12(4) → 24(3) → 35(4) → 47(3) → 58(4) → 70(3) → 9(4) → 69(4) → 58(3) → 46(4) → 35(3) → 23(4) → 12(3) → 72(4) → 61(3) → 45(2) → 34(1) → 22(2) → 11(1) → 71(2) → 60(1) → 48(2) → 37(1) → 49(1) → 60(2).

[0144] The number distributions of the start slots and end slots corresponding to the three parallel branches in the U-phase winding are such that U1 corresponds to 1(1), X1 corresponds to 61(1), U2 corresponds to 71(1), X2 corresponds to 59(2), U3 corresponds to 72(1), and X3 corresponds to 60(2). U1, U2, and U3 are connected in parallel, X1, X2, and X3 are connected in parallel, and finally connected by a bus bar to form the completed U-phase winding. U1, U2, and U3 are located in the adjacent q = 4 same-polarity stator slots 11, and X1, X2, and X3 are also located in the adjacent q = 4 same-polarity stator slots 11.

[0145] In the above application scenario, the second winding method may be used, and the stator winding 20 only requires four types of hairpin coils.

[0146] Here, the number distribution of the starting slot and the ending slot corresponding to the three parallel branch paths in the U-phase winding is such that U1 corresponds to 1(1), X1 corresponds to 61(1), U2 corresponds to 25(1), X2 corresponds to 13(1), U3 corresponds to 49(1), and X3 corresponds to 37(1). U1, U2, and U3 are connected in parallel, X1, X2, and X3 are connected in parallel, and finally connected by a bus bar to form a completed U-phase winding. U1, U2, and U3 are rotationally symmetric with respect to the stator core 10, and all are shifted by 24 stator slots 11. X1, X2, and X3 are also rotationally symmetric with respect to the stator core 10, and all are shifted by 24 stator slots 11.

[0147] In the second winding method, the first parallel branch path of the U-phase winding is introduced from the voltage lead-out position U1 and drawn out from the neutral point lead-out position X1. The slot numbers passed by the series connection of the first parallel branch path are 1(1) → 12(2) → 24(1) → 35(2) → 47(1) → 58(2) → 70(1) → 9(2) → 25(3) → 36(4) → 48(3) → 59(4) → 71(3) → 10(4) → 22(3) → 33(4) → 21(4) → 10(3) → 70(4) → 59(3) → 47(4) → 36(3) → 24(4) → 13(3) → 69(2) → 58(1) → 46(2) → 35(1) → 23(2) → 12(1) → 72(2) → 61(1).

[0148] The second parallel branch path of the U-phase winding is introduced from the voltage lead-out position U2 and drawn out from the neutral point lead-out position X2. The slot numbers passed by the series connection of the second parallel branch path are 25(1) → 36(2) → 48(1) → 59(2) → 71(1) → 10(2) → 22(1) → 33(2) → 49(3) → 60(4) → 72(3) → 11(4) → 23(3) → 34(4) → 46(3) → 57(4) → 45(4) → 34(3) → 22(4) → 11(3) → 71(4) → 60(3) → 48(4) → 37(3) → 21(2) → 10(1) → 70(2) → 59(1) → 47(2) → 36(1) → 24(2) → 13(1).

[0149] The third parallel branch of the U-phase winding is introduced from the voltage lead-out position U3 and led out from the neutral point lead-out position X3. The slot numbers through which the series connection of the third parallel branch passes are 49(1)→60(2)→72(1)→11(2)→23(1)→34(2)→46(1)→57(2)→1(3)→12(4)→24(3)→35(4)→47(3)→58(4)→70(3)→9(4)→69(4)→58(3)→46(4)→35(3)→24(4)→12(3)→72(4)→61(3)→45(2)→34(1)→22(2)→11(1)→71(2)→60(1)→48(2)→37(1).

[0150] Taking a 6-pole 72-slot motor as an example, m = 3, the number of stator slots s = 72, the number of rotor pole pairs p = 3, the number of slots per pole per phase q = 4, and when the number of slot layers n of stator slot 11 is 6, in this embodiment, the first winding method is used, and 7 types of hairpin coils are required in the stator winding 20. The number distributions of the start slots and end slots corresponding to the three parallel branches in the U-phase winding are such that U1 corresponds to 1(1), X1 corresponds to 61(1), U2 corresponds to 71(1), X2 corresponds to 59(2), U3 corresponds to 72(1), and X3 corresponds to 60(2). U1, U2, and U3 are connected in parallel, X1, X2, and X3 are connected in parallel, and finally connected by a bus bar to form a completed U-phase winding. U1, U2, and U3 are located in the adjacent q = 4 stator slots 11 of the same polarity, and X1, X2, and X3 are also located in the adjacent q = 4 stator slots 11 of the same polarity.

[0151] As shown in Fig. 30, the first parallel branch of the U-phase winding is introduced from the voltage lead-out position U1, drawn out from the neutral point lead-out position X1, and the slot numbers through which the series connection of the first parallel branch passes are 1(1)→12(2)→24(1)→35(2)→47(1)→58(2)→70(1)→9(2)→25(3)→36(4)→48(3)→59(4)→71(3)→10(4)→22(3)→33(4)→49(5)→60(6)→72(5)→11(6)→23(5)→34(6)→46(5)→57(6)→45(6)→34(5)→22(6)→11(5)→71(6)→60(5)→48(6)→34(5)→22(6)→11(5)→71(6)→60(5)→48(6)→37(5)→21(4)→10(3)→70(4)→59(3)→47(4)→36(3)→24(4)→13(3)→69(2)→58(1)→46(2)→35(1)→23(2)→12(1)→61(1).

[0152] As shown in Fig. 31, the second parallel branch of the U-phase winding is introduced from the voltage lead-out position U2, drawn out from the neutral point lead-out position X2, and the slot numbers through which the series connection of the second parallel branch passes are 71(1)→10(2)→22(1)→33(2)→49(3)→60(4)→72(3)→11(4)→23(3)→34(4)→46(3)→57(4)→1(5)→12(6)→24(5)→35(6)→47(5)→58(6)→70(5)→9(6)→69(6)→58(5)→46(6)→35(5)→23(6)→12(5)→72(6)→61(5)→45(4)→34(3)→22(4)→11(3)→71(4)→60(3)→48(4)→37(3)→21(2)→10(1)→70(2)→59(1)→47(2)→36(1)→24(2)→13(1)→25(1)→36(2)→48(1)→59(2).

[0153] As shown in FIG. 32, the third parallel branch of the U-phase winding is drawn in from the voltage lead position U3, drawn out from the neutral point lead position X3, and the slot numbers through which the series connection of the third parallel branch passes are 72(1)→11(2)→23(1)→34(2)→46(1)→57(2)→1(3)→12(4)→24(3)→35(4)→47(3)→58(4)→70(3)→9(4)→25(5)→36(6)→48(5)→59(6)→71(5)→10(6)→22(5)→33(6)→21(6)→10(5)→70(6)→59(5)→47(6)→36(5)→24(6)→13(5)→69(4)→58(3)→46(4)→35(3)→23(4)→12(3)→72(4)→61(3)→45(2)→34(1)→22(2)→11(1)→71(2)→60(1)→48(2)→37(1)→49(1)→60(2).

[0154] When the second winding method is used, the stator winding 20 only requires six types of hairpin coils, and the number distribution of the start slot and the end slot corresponding to the three parallel branches in the U-phase winding is such that U1 corresponds to 1(1), X1 corresponds to 61(1), U2 corresponds to 25(1), X2 corresponds to 13(1), U3 corresponds to 49(1), and X3 corresponds to 37(1).

[0155] Since the slot numbers through which the series connection of the first parallel branch passes are the same as those above, the description is omitted.

[0156] The slot numbers through which the series connection of the second parallel branch passes are 25(1) → 36(2) → 48(1) → 59(2) → 71(1) → 10(2) → 22(1) → 33(2) → 49(3) → 60(4) → 72(3) → 11(4) → 23(3) → 34(4) → 46(3) → 57(4) → 1(5) → 12(6) → 24(5) → 35(6) → 47(5) → 58(6) → 70(5) → 9(6) → 69(6) → 58(5) → 46(6) → 35(5) → 23(6) → 12(5) → 72(6) → 61(5) → 45(4) → 34(3) → 22(4) → 11(3) → 71(4) → 60(3) → 48(4) → 37(3) → 21(2) → 10(1) → 70(2) → 59(1) → 47(2) → 36(1) → 24(2) → 13(1).

[0157] The slot numbers through which the series connection of the third parallel branch passes are 49(1) → 60(2) → 72(1) → 11(2) → 23(1) → 34(2) → 46(1) → 57(2) → 1(3) → 12(4) → 24(3) → 35(4) → 47(3) → 58(4) → 70(3) → 9(4) → 25(5) → 36(6) → 48(5) → 59(6) → 71(5) → 10(6) → 22(5) → 33(6) → 21(6) → 10(35) → 70(6) → 59(5) → 47(6) → 36(5) → 24(6) → 13(5) → 69(4) → 58(3) → 46(4) → 35(3) → 23(4) → 12(3) → 72(4) → 61(3) → 45(2) → 34(1) → 22(2) → 11(1) → 71(2) → 60(1) → 48(2) → 37(1).

[0158] In other application scenarios, when a = 2, the pitch of the long-pitch hairpin coil is s / (2p) + 2, the pitch of the full-pitch hairpin coil is s / (2p), and the pitch of the short-pitch hairpin coil is s / (2p) - 2.

[0159] Specifically, the number s of status slots may be 72, the number p of pole pairs of the rotor may be 3, the number n of slot layers of the status slot 11 may be one of 4, 6, 8, and 10, the pitch of the long-pitch hairpin coil is 14, the pitch of the full-pitch hairpin coil is 12, and the pitch of the short-pitch hairpin coil is 10. That is, the combination of the pitches of the hairpin coils 21 in each parallel branch path is 10, 12, 14, and the welding pitch between the hairpin coils in each parallel branch path is all 13.

[0160] Taking a 6-pole 72-slot motor as an example, m = 3, the number s of status slots = 72, the number p of pole pairs of the rotor = 3, the number q of slots per pole per phase = 4, and the number n of slot layers of the status slot 11 = 4.

[0161] In the above application scenario, when using the first winding method, the stator winding 20 only requires 5 types of hairpin coils.

[0162] As shown in FIG. 33, the first parallel branch path of the U-phase winding is led in from the voltage lead-out position U1 and led out from the neutral-point lead-out position X1. The slot numbers passed by the series connection of the first parallel branch path are 72(1) → 13(2) → 23(1) → 36(2) → 46(1) → 59(2) → 69(1) → 10(2) → 24(3) → 37(4) → 47(3) → 60(4) → 70(3) → 11(4) → 21(3) → 34(4) → 22(4) → 9(3) → 71(4) → 58(3) → 48(4) → 35(3) → 25(4) → 12(3) → 70(2) → 57(1) → 47(2) → 34(1) → 24(2) → 11(1) → 1(2) → 60(1).

[0163] As shown in Fig. 34, the second parallel branch of the U-phase winding is introduced from the voltage lead-out position U2 and led out from the neutral point lead-out position X2. The slot numbers through which the series connection of the second parallel branch passes are 70(1) → 11(2) → 21(1) → 34(2) → 48(3) → 61(4) → 71(3) → 12(4) → 22(3) → 35(4) → 45(3) → 58(4) → 46(4) → 33(3) → 23(4) → 10(3) → 72(4) → 59(3) → 49(4) → 36(3) → 22(2) → 9(1) → 71(2) → 58(1) → 48(2) → 35(1) → 25(2) → 12(1) → 24(1) → 37(2) → 47(1) → 60(2).

[0164] As shown in Fig. 35, the third parallel branch of the U-phase winding is introduced from the voltage lead-out position U3 and led out from the neutral point lead-out position X3. The slot numbers through which the series connection of the third parallel branch passes are 71(1) → 12(2) → 22(1) → 35(2) → 45(1) → 58(2) → 72(3) → 13(4) → 23(3) → 36(4) → 46(3) → 59(4) → 69(3) → 10(4) → 70(4) → 57(3) → 47(4) → 34(3) → 24(4) → 11(3) → 1(4) → 60(3) → 46(2) → 33(1) → 23(2) → 10(1) → 72(2) → 59(1) → 49(2) → 36(1) → 48(1) → 61(2).

[0165] The number distributions of the start slots and end slots corresponding to the three parallel branches are such that U1 corresponds to 72(1), X1 corresponds to 60(1), U2 corresponds to 70(1), X2 corresponds to 60(2), U3 corresponds to 71(1), and X3 corresponds to 61(2).

[0166] In the above application scenario, when using the second winding method, the stator winding 20 only requires four types of hairpin coils. Compared with the first winding method, the starting slot and ending slot of the parallel branch paths are different. For the specific winding method, reference can be made to the above first winding method, and the description is omitted here. Here, the number distributions of the starting slots and ending slots corresponding to the three parallel branch paths are such that U1 corresponds to 72(1), X1 corresponds to 60(1), U2 corresponds to 24(1), X2 corresponds to 12(1), U3 corresponds to 48(1), and X3 corresponds to 36(1).

[0167] Taking a 6-pole 72-slot motor as an example, m = 3, the number of stator slots s = 72, the number of rotor pole pairs p = 3, the number of slots per pole per phase q = 4, and the number of slot layers n = 6 of stator slot 11. In this embodiment, the first winding method is used, and seven types of hairpin coils are required in the stator winding 20.

[0168] As shown in FIG. 36, the first parallel branch path of the U-phase winding is led in from the voltage lead-out position U1 and led out from the neutral point lead-out position X1. The slot numbers passed by the series connection of the first parallel branch path are 72(1) → 13(2) → 23(1) → 36(2) → 46(1) → 59(2) → 69(1) → 10(2) → 24(3) → 37(4) → 47(3) → 60(4) → 70(3) → 11(4) → 21(3) → 34(4) → 48(5) → 61(6) → 71(5) → 12(6) → 22(5) → 35(6) → 45(5) → 58(6) → 46(6) → 33(5) → 23(6) → 10(5) → 72(6) → 59(5) → 49(6) → 36(5) → 22(4) → 9(3) → 71(4) → 58(3) → 48(4) → 35(3) → 25(4) → 12(3) → 70(2) → 57(1) → 47(2) → 34(1) → 24(2) → 11(1) → 1(2) → 60(1).

[0169] As shown in Fig. 37, the second parallel branch of the U-phase winding is drawn in from the voltage lead position U2 and drawn out from the neutral point lead position X2. The slot numbers through which the series connection of the second parallel branch passes are 70(1)→11(2)→21(1)→34(2)→48(3)→61(4)→71(3)→12(4)→22(3)→35(4)→45(3)→58(4)→72(5)→13(6)→23(5)→36(6)→46(5)→59(6)→69(5)→10(6)→70(6)→57(5)→47(6)→34(5)→24(6)→11(5)→1(6)→60(5)→46(4)→33(3)→23(4)→10(3)→72(4)→59(3)→49(4)→36(3)→22(2)→9(1)→71(2)→58(1)→48(2)→35(1)→25(2)→12(1)→24(1)→37(2)→47(1)→60(2).

[0170] As shown in Fig. 38, the third parallel branch of the U-phase winding is drawn in from the voltage lead position U3 and drawn out from the neutral point lead position X3. The slot numbers through which the series connection of the third parallel branch passes are 71(1)→12(2)→22(1)→35(2)→45(1)→58(2)→72(3)→3(4)→23(3)→36(4)→46(3)→59(4)→69(3)→10(4)→24(5)→37(6)→47(5)→60(6)→70(5)→11(6)→21(5)→34(6)→22(6)→9(5)→71(6)→58(5)→48(6)→35(5)→25(6)→12(5)→70(4)→57(3)→47(4)→34(3)→24(4)→11(3)→1(4)→60(3)→46(2)→33(1)→23(2)→10(1)→72(2)→59(1)→49(2)→36(1)→48(1)→61(2).

[0171] The number distribution of the start slot and the end slot corresponding to the three parallel branches in the U-phase winding is such that U1 corresponds to 72(1), X1 corresponds to 60(1), U2 corresponds to 70(1), X2 corresponds to 60(2), U3 corresponds to 71(1), and X3 corresponds to 61(2).

[0172] After winding using the winding method according to the embodiment of the present application, the back electromotive force harmonic content at the peak torque operating point of a 6-pole, 72-slot flat wire motor is compared. The back electromotive force harmonic content of a full-pitch winding motor in the prior art is 4.75%, while the back electromotive force harmonic content using the embodiment of the present application is 3.98%, a decrease of 16.2%, which shows that the winding method according to the present application reduces back electromotive force harmonics and improves motor efficiency.

[0173] According to another aspect of the present invention, there is further provided a power train, which includes a reducer and the above-mentioned flat wire motor, wherein the flat wire motor is transmission-connected to the reducer, specifically, a drive shaft of the flat wire motor and an input shaft of the reducer are transmission-connected by a transmission member such as a shaft coupling, and a driving force is output from the flat wire motor to the reducer.

[0174] According to yet another aspect of the present application, there is further provided a vehicle including the above-mentioned powertrain, the powertrain being installed in the vehicle and providing the vehicle with driving power. Specifically, in this embodiment, the vehicle may be a new energy vehicle driven by electric energy. Specifically, the new energy vehicle may be a hybrid electric vehicle, a pure electric vehicle, a fuel cell electric vehicle, etc., and may be a vehicle using a high-efficiency accumulator such as a supercapacitor, a flywheel battery, or a flywheel accumulator as an electric energy source.

[0175] Unlike the prior art, the present application discloses a stator, a flat wire motor, a power train, and a vehicle. The plurality of parallel branch paths of each phase winding are rotationally symmetric in the circumferential direction. Thus, the magnetic field distributions of the plurality of parallel branch paths in each phase winding are the same, and the potentials are balanced, thereby avoiding the circulating current generated between the parallel branch paths, significantly reducing the additional AC copper loss at high frequencies, improving the efficiency of the flat wire motor during high-speed operation, avoiding local overheating of the winding, extending the service life of the flat wire motor, and further, the hairpin coils of each parallel branch path are provided across N slot layers in different stator slots. Thereby, the potential phase difference due to the positions in the stator slots of the plurality of parallel branch paths of each phase winding can be eliminated. By limiting the number of slot layers N in the stator slots and the total number of slot layers occupied by each corresponding parallel branch path in each stator slot, the wire type of the hairpin coils can be reduced, the manufacturing molds of the flat wire motor can be reduced, the manufacturing cost can be reduced, and the processing and manufacturing efficiency can be effectively improved.

[0176] In the description of the present application, the descriptions referring to terms such as "one embodiment", "several embodiments", "example", "specific example", or "several examples" mean that the specific features, structures, materials, or characteristics described in relation to the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic expressions for the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics can be combined in any appropriate manner in one or more embodiments or examples. Note that, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0177] The above is only an embodiment of the present application and does not limit the patent scope of the present application. The equivalent structure or equivalent flow conversion performed using the content of the specification and drawings of the present application, or the direct or indirect application to other related technical fields is included in the patent protection scope of the present application for the same reason.

Claims

1. A stator of a flat wire motor, comprising: a stator core having a plurality of stator slots uniformly arranged along its circumferential direction on an inner wall; a stator winding; The stator winding includes a three-phase winding, each phase winding includes a plurality of parallel branch paths, the plurality of parallel branch paths are rotationally symmetric in the circumferential direction, each of the parallel branch paths is connected by a connecting wire and includes a plurality of hairpin coils with different pitches, N layers of the hairpin coils are provided in any of the stator slots, the hairpin coils of each parallel branch path are provided across N slot layers in different stator slots, and the three-phase winding is sequentially and periodically arranged along the circumferential direction of the stator core; When N = (2n + 1)×2, the combination of the total number of slot layers occupied by each parallel branch path in each stator slot is 2n, or 2n, 2n - 1, 2n - 2; When N = 2n×2, the combination of the total number of slot layers occupied by each parallel branch path in each stator slot is 2n, 2n - 1, or 2n, 2n - 1, 2n - 2; When N = 2n + 1, the combination of the total number of slot layers occupied by each parallel branch path in each stator slot is n, n - 1, or n, n - 1, n - 2; N is a positive integer and is 4 or more, and the total number of slot layers of each parallel branch path in each stator slot is also a positive integer, stator.

2. When the total number of slot layers occupied by each parallel branch path in the stator slot is 1, the position of the one slot layer is the first layer or the Nth layer of the stator slot; When the total number of slot layers occupied by each parallel branch path in the stator slot is 2, the two slot layers are provided adjacent to each other in the stator slot, or the two slot layers are respectively the first layer and the Nth layer in the stator slot; When the total number of slot layers occupied by each parallel branch path in the stator slot is 3, two of the three slot layers are provided adjacent to each other, the position of the remaining one slot layer is the first layer or the Nth layer of the stator slot, and it is provided separated from the other two slot layers by four slot layers; When the total number of slot layers occupied by each of the parallel branch paths in the status slot is 4, the four slot layers are divided into two groups, each group is provided with a separation of four slot layers, and each group includes two adjacent slot layers. The stator according to claim 1.

3. Each phase winding includes three parallel branch paths. The stator according to claim 2.

4. The number of the status slots is 54 or 72. The stator according to claim 3.

5. The combination of the pitches of the hairpin coils in each of the parallel branch paths is 8, 9, 11, 12, 16. The stator according to claim 3 or 4.

6. The pitch of the hairpin coils in the same slot layer of each of the parallel branch paths is all 9. The stator according to claim 3 or 4.

7. The pitch of the hairpin coils in the first slot layer or the Nth slot layer of each of the parallel branch paths is 8 or 8, 11. The stator according to claim 3 or 4.

8. Each of the parallel branch paths has an inlet end located in the Nth layer of the slot layer and an outlet end located in the N - 1th layer of the slot layer, or The inlet end and the outlet end of each of the parallel branch paths are both located in the first slot layer and the Nth slot layer. The stator according to claim 3 or 4.

9. The welding pitch between the hairpin coils in each of the parallel branch paths is all 9 or 11. The stator according to claim 3 or 4.

10. Each of the parallel branch paths includes a long-pitch hairpin coil with a pitch of s / (2p) + a, a full-pitch hairpin coil with a pitch of s / (2p), and a short-pitch hairpin coil with a pitch of s / (2p) + a - 4, where s is the number of status slots, p is the number of the parallel branch paths, and a is an integer of 2 or more and 4 or less. The stator according to any one of claims 1 to 4.

11. In each of the parallel branch paths, the first leg and the second leg of the short-pitch hairpin coil are respectively located in the kth slot layer and the k + 1th slot layer, the first leg and the second leg of the long-pitch hairpin coil are respectively located in the k + 1th slot layer and the k + 2th slot layer, and the first leg and the second leg of the full-pitch hairpin coil are both distributed in the first slot layer or the nth slot layer, where k is an odd number of 1 or more and n or less. The stator according to claim 10.

12. The number of slots per pole per phase of the flat wire motor is q, and the voltage lead wires of the p parallel branches of each phase winding are located in s of the status slots and are located in the same slot layer or adjacent slot layers of different status slots. The neutral point lead wires of the p parallel branches of each phase winding are located in s of the status slots and are located in the same slot layer or adjacent slot layers of different status slots. The stator according to claim 11.

13. The voltage lead wire and the neutral point lead wire are both located in the first slot layer or the nth slot layer. The stator according to claim 11.

14. The welding pitch between the hairpin coils in each parallel branch is s / (2p). The stator according to claim 12 or 13.

15. n is an even number, a = 4, the short-pitch hairpin coil is the full-pitch hairpin coil, and in the phase belt distribution of the three-phase winding, the polarity distribution of each odd layer is the same, the polarity distribution of each even layer is the same, and it is shifted by one status slot with respect to the polarity distribution of the odd layer. The stator according to claim 11.

16. The number of slot layers of the status slot is one of 4, 6, 8, and 10. The combination of the pitches of the hairpin coils in each parallel branch is 10, 12, 14. The welding pitch between the hairpin coils in each parallel branch is 13. The stator according to claim 11.

17. Each hairpin coil includes a first leg, a second leg, a connection segment, a first bending segment, and a second bending segment. The first leg and the second leg are provided in parallel and are inserted into the slot layers of different status slots respectively. The connection segment is connected to one end of the first leg and the second leg. The first bending segment is connected to the other end of the first leg. The second bending segment is connected to the other end of the second leg. Welding ends are connected to both the first bending segment and the second bending segment. The stator according to claim 1.

18. The bending directions of the first bending segment and the second bending segment are the same and parallel or symmetrically provided. The stator according to claim 17.

19. A rotor and a stator according to any one of claims 1 to 18, wherein the rotor is a flat wire motor provided in a space surrounded by an inner wall of the stator core. **Claim 20** A speed reducer and a flat wire motor according to claim 19, wherein the flat wire motor is a power train transmission-connected to the speed reducer. **Claim 21** A vehicle including the power train according to claim 20.

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