Flat wire motor and its stator

Abstract

Embodiments of the present application provide a flat wire motor and its stator. The stator includes a stator core and a stator winding installed on the stator core. A plurality of winding grooves are formed on the inner wall of the stator core, and the plurality of winding grooves are arranged along the circumferential direction of the inner wall of the stator core. The stator winding includes a plurality of coil units, each coil unit includes a first coil and a second coil, the first coil includes a first insertion portion, a second insertion portion, and a first connection portion connecting the first insertion portion and the second insertion portion, the second coil includes a third insertion portion, a fourth insertion portion, and a second connection portion connecting the third insertion portion and the fourth insertion portion, the first insertion portion, the third insertion portion, the fourth insertion portion, and the second insertion portion are arranged along the circumferential direction and are respectively inserted into different winding grooves, the first insertion portion is connected to the fourth insertion portion, and the second connection portion is located on the side of the first connection portion facing the stator core. Embodiments of the present application can simplify the wire embedding process and reduce the height of the stator winding end portion.

Description

Technical Field

[0001] The present application relates to the field of power devices, and more specifically to a flat wire motor and its stator.

Background Art

[0002] Since the flat wire motor has a high copper filling rate, it is advantageous for the heat dissipation of the motor winding, and has advantages in aspects such as improving the withstand voltage capacity of the winding and shortening the length of the winding end. Furthermore, the motor torque density and power density can be improved. Therefore, the flat wire motor has become an important means for promoting the weight reduction of automobiles, improving the cruising range of electric vehicles, improving the space utilization rate of automobiles, and reducing the power train cost.

[0003] How to simplify the wire embedding structure of the motor and reduce the height of the winding end is an important research direction in the motor field.

Summary of the Invention

Means for Solving the Problems

[0004] The present application provides a flat wire motor and its stator that can simplify the wire embedding process and reduce the height of the stator winding end.

[0005] According to a first aspect, an embodiment of the present application provides a stator of a flat wire motor including a stator core and a stator winding installed on the stator core. A plurality of winding grooves are formed on the inner wall of the stator core, and the plurality of winding grooves are installed along the circumferential direction of the inner wall of the stator core. The stator winding includes a plurality of coil units, each coil unit includes a first coil and a second coil, the first coil includes a first insertion portion, a second insertion portion, and a first connection portion connecting the first insertion portion and the second insertion portion, the second coil includes a third insertion portion, a fourth insertion portion, and a second connection portion connecting the third insertion portion and the fourth insertion portion, the first insertion portion, the third insertion portion, the fourth insertion portion, and the second insertion portion are arranged along the circumferential direction and inserted into different winding grooves respectively, the first insertion portion is connected to the fourth insertion portion, and the second connection portion is located on a side of the first connection portion facing the stator core.

[0006] In the above technical solution, the first coil is a long-distance coil, the second coil is a short-distance coil, and the combination of the long-distance coil and the short-distance coil can form a concentric nested arrangement at the wire insertion end of the stator winding. The second connection portion of the second coil can be drilled between the first connection portion and the stator core, thereby reducing the space occupied additionally in the axial direction of the stator core and lowering the height of the coil unit in the axial direction. The stator winding uses a plurality of coil units of the same type, reduces the linearity of the coil, simplifies the wire embedding process, and can lower the height of the end of the stator winding.

[0007] In some embodiments, the first coil further includes a first extension portion and a second extension portion. The first extension portion extends from one end away from the first connection portion of the first insertion portion, and the second extension portion extends from one end away from the first connection portion of the second insertion portion. The second coil further includes a third extension portion and a fourth extension portion. The third extension portion extends from one end away from the second connection portion of the third insertion portion, and the fourth extension portion extends from one end away from the second connection portion of the fourth insertion portion. The first extension portion is bent toward the fourth insertion portion with respect to the first insertion portion, and the fourth extension portion is bent toward the first insertion portion with respect to the fourth insertion portion and connected to the first extension portion.

[0008] In the above technical solution, the first extension portion and the fourth extension portion are bent relatively, which can reduce the requirements for the sizes of the first extension portion and the fourth extension portion and can reduce the height at the welding end of the stator winding.

[0009] In some embodiments, the number of winding grooves is 12·M, where M is a positive integer. The span between the first insertion portion and the second insertion portion of the first coil is 7 winding grooves, and the span between the third insertion portion and the fourth insertion portion of the second coil is 5 winding grooves.

[0010] The above technical solution can expand the usage range of the winding design and can be adapted to different voltage and power ranges. The span of the first coil and the span of the second coil are adapted to the number of winding grooves, so that a plurality of coil units can be fitted into the winding grooves.

[0011] In some embodiments, the first insertion portion, the third insertion portion, the fourth insertion portion, and the second insertion portion are respectively flat wire conductors in corresponding winding grooves. The flat wire conductors in each winding groove are arranged in n layers, where n is a positive even number. Along the direction from the groove bottom of the winding groove toward the groove opening of the winding groove, the n layers of flat wire conductors are denoted as layer L1,......, layer L i layer,...... and L n layer, where 1≦i≦n.

[0012] In some embodiments, the stator winding includes a plurality of phase windings, each phase winding includes at least one branch circuit, and the branch circuit includes a plurality of coil units. In the branch circuit, the flat wire conductors connecting at least two coil units to each other are in the same layer.

[0013] In the above technical solution, at least two coil units can use full-distance welding, without the need for welding across layers, thereby simplifying the welding process. The flat wire conductors connected in the same layer can also balance the groove potential of the branch circuit and reduce the circulating current loss between branch circuits.

[0014] In some embodiments, in the branch circuit, the L1 layers of at least two coil units are connected. The L1 layers of the two coil units are close to the outer ends along the radial direction of the stator core, making it easy to realize welding.

[0015] In some embodiments, in the branch circuit, the L n layers of at least two coil units are connected. The L n layers of the two coil units are close to the inner ends along the radial direction of the stator core, making it easy to realize welding.

[0016] In some embodiments, the stator winding includes a plurality of phase windings, each phase winding includes at least one branch circuit, and the branch circuit includes a plurality of coil units. A first lead wire and a second lead wire are provided at both ends of the branch circuit, the first lead wire and the second lead wire are connected to different flat wire conductors, and the flat wire conductors connected to the first lead wire and the flat wire conductors connected to the second lead wire are provided in different winding grooves.

[0017] In the above technical solution, the flat wire conductors connected to the first lead wire and the flat wire conductors connected to the second lead wire are provided in different winding grooves, thereby increasing the distance between the first lead wire and the second lead wire and reducing the risk of the first lead wire and the second lead wire contacting and short-circuiting.

[0018] In some embodiments, the flat wire conductor connected to the first lead wire and the flat wire conductor connected to the second lead wire are in the same layer.

[0019] The above technical solution is advantageous for the arrangement of the bus bar and facilitates the connection between the first lead wire, the second lead wire and the external circuit.

[0020] In some embodiments, each phase winding includes a plurality of branch circuits, and two of the plurality of branch circuits are defined as a first branch circuit and a second branch circuit. The span between the flat wire conductor connected to the first lead wire of the first branch circuit and the flat wire conductor connected to the first lead wire of the second branch circuit is equal to or less than the pole pitch.

[0021] The above technical solution can reduce the distance between the first lead wires of the two branch circuits, facilitating the connection of the first lead wires of the two branch circuits, and is advantageous for the arrangement of the bus bar and the implementation of the winding processing process.

[0022] In some embodiments, the flat wire conductor connected to the first lead wire of the first branch circuit and the flat wire conductor connected to the first lead wire of the second branch circuit are provided in the same winding groove.

[0023] The above technical solution further reduces the distance between the first lead wires of the two branch circuits by drawing out the first lead wires of the two branch circuits from within the same winding groove, facilitating the connection of the first lead wires of the two branch circuits, and is advantageous for the arrangement of the bus bar and the implementation of the winding processing process.

[0024] In some embodiments, all the first lead wires in the plurality of phase windings are connected to flat wire conductors in different winding grooves.

[0025] The above technical solution can increase the distance between each lead wire and reduce the voltage stress between phases.

[0026] In some embodiments, the stator winding includes a plurality of phase windings, each phase winding includes at least one branch circuit, and the branch circuit includes a plurality of coil units. The branch circuit includes k layers of flat wire conductors, where k is a positive integer greater than 1. Along the direction in which current flows, the k layers of flat wire conductors are denoted as layer A1, layer A2,..., layer A k-1 layer and A k layer. Any two adjacent flat wire conductors located in the same winding groove of the branch circuit are respectively denoted as A j layer and A l layer, where 1 ≤ j < l ≤ k. And l - j ≤ k / 2.

[0027] The greater the difference in the numbers of the flat wire conductors, the greater the differential pressure between the two flat wire conductors. If the difference in the numbers of two adjacent flat wire conductors located in the same winding groove is too large, the voltage stress between the flat wire conductors in the winding groove will become excessive. The above technical solution sets l - j ≤ k / 2, thereby reducing the voltage stress between the flat wire conductors in the winding groove.

[0028] In some embodiments, the stator winding includes a plurality of phase windings, each phase winding includes at least one branch circuit, and the branch circuit includes a plurality of coil units. The phase winding includes 2P pole-phase groups, where P is a positive integer. Each phase winding includes a plurality of branch circuits, and the plurality of coil units of at least one branch circuit are distributed among all the pole-phase groups.

[0029] The above technical solution can reduce the imbalance of the branch circuit potential due to the eccentricity of the rotor.

[0030] In some embodiments, the stator winding includes a plurality of phase windings, each phase winding includes at least one branch circuit, and the branch circuit includes a plurality of coil units. The phase winding includes 2P pole-phase groups, where P is a positive integer. Each phase winding includes a plurality of branch circuits, and the plurality of coil units of each branch circuit are distributed among some of the pole-phase groups.

[0031] According to a second aspect, an embodiment of the present application provides a flat wire motor, including a rotor and a stator of any one of the embodiments of the first aspect. The rotor is provided in a space formed by being surrounded by the inner wall of the stator core.

[0032] To more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings that need to be used in the embodiments of the present application. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on the drawings on the premise of not paying creative labor.

Brief Description of the Drawings

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Embodiments for Carrying Out the Invention

[0034] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following clearly describes the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0035] Unless otherwise defined, all technical and scientific terms used in this application shall have the same meaning as commonly understood by those skilled in the technical field to which this application pertains. In this application, the terms used in the description of the application are only for describing specific embodiments and are not intended to limit this application. The terms "comprising" and "having" and any variations thereof in the description of the specification, claims, and drawings of this application are intended to cover non-exclusive "comprising". The terms "first", "second", etc. in the description of the specification, claims, or drawings of this application are not for describing a specific order or primary-secondary relationship, but for distinguishing different objects.

[0036] The "embodiments" referred to in this application mean that the specific features, structures, or characteristics described in connection with the embodiments may be included in at least one embodiment of this application. The appearance of this phrase at each position in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0037] In the description of this application, unless otherwise specifically defined and limited, the terms "attachment", "connection", "linkage", "installation" should be understood in a broad sense. For example, it may be a fixed connection, a removable connection, or an integral connection, a direct connection, an indirect connection through an intermediate medium, or a communication inside two elements. Those skilled in the art can understand the specific meaning of these terms in this application according to specific situations.

[0038] The term "and / or" in this application only describes the relationship of the relevant objects and represents that three relationships may exist. For example, A and / or B may represent three cases: A alone, the combination of A and B, and B alone. Also, the character " / " in this application generally represents that the relevant objects before and after are in an "or" relationship.

[0039] In the embodiments of the present application, descriptions with the same reference signs represent the same members. For the sake of brevity, in different embodiments, detailed descriptions of the same members are omitted. It should be understood that the thicknesses of various members, sizes such as aspects, and the thickness and aspect of the entire integrated device shown in the drawings are for illustrative purposes only and do not constitute any limitation to the present application.

[0040] The term "plurality" as used in the present application refers to two or more (including two).

[0041] Currently, in the drive motors of new energy vehicles, the motor stator can be divided into circular wire conductors and flat wire conductors according to the cross-sectional shape of the coils forming the stator winding. A motor using flat wire conductors is called a flat wire motor. The flat wire motor can effectively improve the slot fill factor and improve the power density and torque density.

[0042] The inventor noticed that as the number of flat wire conductors in the winding groove gradually increases, the number and shape of the coils also increase accordingly, thereby causing intersections in the wire embedding direction of the coils and increasing the difficulty of wire embedding. At the wire insertion end of the stator winding, since the coils are stacked on top of each other, the height of the winding end increases, the space at the winding end becomes cramped, and there is a possibility of insulation failure during long-term operation.

[0043] In view of this, the embodiments of the present application provide a flat wire motor and its stator that can reduce the shape of the coils, simplify the wire embedding process, and lower the height of the stator winding end by adjusting the connection method of the coils.

[0044] For ease of understanding, the following is a description of the technical terms that appear in the present application as follows.

[0045] Stator: Refers to the stationary part of the motor, and its function is to generate a rotating magnetic field.

[0046] Rotor: It refers to the rotating member in a motor, and its function is to realize the conversion between electrical energy and mechanical energy.

[0047] Span: It refers to the distance that two element sides of the same element in the motor winding span on the armature surface, and is generally represented by the number of winding grooves opened in the stator core.

[0048] Number of pole pairs P: The number of pole pairs is abbreviated as the pole pairs. After the motor winding is energized, the formed magnetic poles appear in the form of pairs of N poles and S poles. The total number of magnetic poles is 2P.

[0049] Pole pitch: The pole pitch refers to the distance occupied by each pole of the motor along the circumferential surface of the air gap. The pole pitch can be represented by the number of winding grooves of the stator core. Exemplarily, the pole pitch is Z / 2P, where Z is the total number of winding grooves of the stator core.

[0050] Pole-phase group: In an AC motor, a plurality of coils belonging to the in-phase winding are connected in series in one pole pitch to form a group, which is called a pole-phase group or also a coil group. The current direction and electromagnetic action of each coil in the pole-phase group are all the same, and these coils jointly generate the magnetic poles in this phase winding.

[0051] Phase winding: The phase winding refers to a set of windings that are connected in series or in parallel by one or more parallel-connected branch circuits in a predetermined connection method.

[0052] FIG. 1 is a schematic structural diagram of one of the stators of a flat wire motor according to some embodiments of the present application, FIG. 2 is a schematic structural diagram of the stator in FIG. 1 at another angle, FIG. 3 is a schematic cross-sectional diagram of the stator shown in FIG. 1, FIG. 4 is an enlarged schematic diagram of block A in FIG. 3, FIG. 5 is a schematic structural diagram of a coil unit of the stator according to some embodiments of the present application, and FIG. 6 is a partial schematic diagram of the stator according to some embodiments of the present application.

[0053] As shown in FIGS. 1 to 6, some embodiments of the present application provide a stator 100 of a flat wire motor including a stator core 200 and a stator winding 300 installed on the stator core 200. A plurality of winding grooves 220 are formed in the inner wall 210 of the stator core 200, and the plurality of winding grooves 220 are installed along the circumferential direction of the inner wall 210 of the stator core 200. The stator winding 300 includes a plurality of coil units 310, each coil unit 310 includes a first coil 311 and a second coil 312, the first coil 311 includes a first insertion part 3111, a second insertion part 3112 and a first connection part 3113 connecting the first insertion part 3111 and the second insertion part 3112, the second coil 312 includes a third insertion part 3121, a fourth insertion part 3122 and a second connection part 3123 connecting the third insertion part 3121 and the fourth insertion part 3122, the first insertion part 3111, the third insertion part 3121, the fourth insertion part 3122 and the second insertion part 3112 are arranged along the circumferential direction and are respectively inserted into different winding grooves 220, the first insertion part 3111 is connected to the fourth insertion part 3122, and the second connection part 3123 is located on the side of the first connection part 3113 facing the stator core 200.

[0054] The stator core 200 is divided into an insertion end 230 and a protruding end 240 along its axial direction, and the winding groove 220 can extend from the insertion end 230 to the protruding end 240.

[0055] The first coil 311 and the second coil 312 may be hairpin coils. Along the axial direction of the stator core 200, the stator winding 300 may include a wire insertion end 320 and a welding end 330. The wire insertion end 320 of the stator winding 300 may be located at the insertion end 230 of the stator core 200, and the welding end 330 of the stator winding 300 may be located at the protruding end 240 of the stator core 200. When winding the coil, the first coil 311 and the second coil 312 can be inserted into the winding groove 220 through the insertion end 230 and protrude from the winding groove 220 through the protruding end 240.

[0056] The first connecting portion 3113 and the second connecting portion 3123 are located on the same side in the axial direction of the stator core 200. Exemplarily, both the first connecting portion 3113 and the second connecting portion 3123 are installed at the wire insertion end 320 of the stator winding 300.

[0057] The winding grooves 220 accommodating the first insertion portion 3111, the winding grooves 220 accommodating the third insertion portion 3121, the winding grooves 220 accommodating the fourth insertion portion 3122, and the winding grooves 220 accommodating the second insertion portion 3112 are arranged along the circumferential direction.

[0058] The first coil 311 and the second coil 312 may be directly connected or may be indirectly connected via other conductive structures. Exemplarily, a portion protruding from the winding groove of the first coil and a portion protruding from the winding groove of the second coil can be connected, thereby connecting the first insertion portion 3111 and the fourth insertion portion 3122. Alternatively, a conductive strip may be installed on one side of the stator core, and both ends of the conductive strip are welded to the first insertion portion 3111 and the fourth insertion portion 3122 respectively, thereby connecting the first insertion portion 3111 and the fourth insertion portion 3122.

[0059] In the embodiment of the present application, the first coil 311 is a long-distance coil, the second coil 312 is a short-distance coil, and the combination of the long-distance coil and the short-distance coil can form a concentric nested arrangement at the wire insertion end 320 of the stator winding 300. The second connecting portion 3123 of the second coil 312 can be drilled between the first connecting portion 3113 and the stator core 200, thereby reducing the space overly occupied in the axial direction of the stator core 200 and lowering the height of the coil unit 310 in the axial direction. The stator winding 300 uses a plurality of coil units 310 of the same type, which can reduce the linearity of the coil, simplify the wire embedding process, and lower the height of the end portion of the stator winding 300.

[0060] With this connection method, the first coil 311 and the second coil 312 form adjacent coils in a single branch circuit and are connected in series. Moreover, there is a relatively large distributed capacitance at the connection site between the wire insertion end 320 and the welding end 330 for the first coil 311 and the second coil 312. This is advantageous for absorbing the high-frequency voltage impact of the driver, reducing the voltage oscillation amplitude of the first coil 311 and the second coil 312, and improving the insulation reliability.

[0061] In some embodiments, the plurality of winding grooves 220 are uniformly installed along the circumferential direction of the inner wall 210 of the stator core 200. In other words, in the circumferential direction, the plurality of winding grooves 220 are installed at equal intervals. When designing the coil, the coil span may be determined based on the number of slots, thereby reducing the linearity of the coil and simplifying the wire embedding process.

[0062] In some embodiments, the winding groove 220 extends along the axial direction of the stator core 200 and penetrates the stator core 200 along the axial direction of the stator core 200. This embodiment can reduce the bending of the coil during the process of inserting the coil into the winding groove 220 and lower the assembly difficulty.

[0063] In some embodiments, the first coil 311 further includes a first extension portion 3114 and a second extension portion 3115. The first extension portion 3114 extends from one end of the first connection portion 3113 of the first insertion portion 3111 away from the first connection portion 3113, and the second extension portion 3115 extends from one end of the first connection portion 3113 of the second insertion portion 3112 away from the first connection portion 3113. The first extension portion 3114 and the second extension portion 3115 protrude from the winding groove 220 to facilitate connection with other coils.

[0064] Exemplarily, the first coil 311 is a hairpin coil. Before being inserted into the winding groove 220, the first coil 311 may include two straight sides, and the two straight sides are inserted into the winding groove 220 through the insertion end 230. The portions of the two straight sides accommodated in the winding groove 220 respectively form a first insertion part 3111 and a second insertion part 3112, and the portions extending through the protruding ends 240 of the two straight sides respectively form a first extension part 3114 and a second extension part 3115.

[0065] Both the first extension part 3114 and the second extension part 3115 are installed at the welding end 330 of the stator winding 300. After inserting the first coil 311 into the stator core 200, the first extension part 3114 and the second extension part 3115 can be bent to weld the first extension part 3114 and the second extension part 3115 to other coils.

[0066] In some embodiments, the second coil 312 further includes a third extension part 3124 and a fourth extension part 3125. The third extension part 3124 extends from one end of the second connection part 3123 of the third insertion part 3121 away from the second connection part 3123, and the fourth extension part 3125 extends from one end of the second connection part 3123 of the fourth insertion part 3122 away from the second connection part 3123. The third extension part 3124 and the fourth extension part 3125 protrude from the winding groove 220 to facilitate connection with other coils.

[0067] Exemplarily, the second coil 312 is a hairpin coil.

[0068] In some embodiments, the first extension part 3114 is bent toward the fourth insertion part 3122 with respect to the first insertion part 3111, and the fourth extension part 3125 is bent toward the first insertion part 3111 with respect to the fourth insertion part 3122 and connected to the first extension part 3114.

[0069] The first extension part 3114 and the fourth extension part 3125 are bent relatively, which can reduce the requirements for the sizes of the first extension part 3114 and the fourth extension part 3125 and reduce the height at the welding end 330 of the stator winding 300.

[0070] In some embodiments, the first extension portion 3114 is welded to the fourth extension portion 3125. The welding process is simple and can reduce the contact resistance between the first extension portion 3114 and the fourth extension portion 3125.

[0071] In some embodiments, the second extension portion 3115 is bent with respect to the second insertion portion 3112 to facilitate welding with other coils. This application does not limit the bending direction of the second extension portion 3115. Exemplarily, the second extension portions 3115 of some coil units 310 may be bent along different directions.

[0072] In some embodiments, the third extension portion 3124 is bent with respect to the third insertion portion 3121 to facilitate welding with other coils. This application does not limit the bending direction of the third extension portion 3124. Exemplarily, the third extension portions 3124 of some coil units 310 may be bent along different directions.

[0073] In some embodiments, the number of winding grooves 220 is 12·M, where M is a positive integer. The span between the first insertion portion 3111 and the second insertion portion 3112 of the first coil 311 is 7 winding grooves 220, and the span between the third insertion portion 3121 and the fourth insertion portion 3122 of the second coil 312 is 5 winding grooves 220.

[0074] Exemplarily, the number of winding grooves 220 may be 12, 24, 36, 48, 60, or 72. This embodiment can expand the usage range of the winding design and adapt to different voltage and power ranges.

[0075] The first coil 311 is a long-distance coil, and its span is 7 winding grooves 220. The second coil 312 is a short-distance coil, and its span is 5 winding grooves 220.

[0076] The combination of the long-distance coil and the short-distance coil can form a concentric nested arrangement at the wire insertion end 320 of the stator winding 300. The second connection portion 3123 of the second coil 312 can be drilled between the first connection portion 3113 and the stator core 200, thereby reducing the space unnecessarily occupied in the axial direction of the stator core 200 and lowering the height of the coil unit 310 in the axial direction. The span of the first coil 311 and the span of the second coil 312 are adapted to the number of winding grooves 220, thereby enabling a plurality of coil units 310 to be fitted into the winding grooves 220.

[0077] In some embodiments, the first insertion portion 3111, the third insertion portion 3121, the fourth insertion portion 3122, and the second insertion portion 3112 are flat wire conductors in the corresponding winding grooves 220 respectively. The flat wire conductors in each winding groove 220 are installed in n layers, where n is a positive even number. Along the direction from the groove bottom 221 to the groove opening 222 of the winding groove 220, the n layers of flat wire conductors are denoted as layer L1,......, layer L i i,......, and layer L n i, where 1 ≤ i ≤ n.

[0078] The first insertion portion 3111, the second insertion portion 3112, the third insertion portion 3121, and the fourth insertion portion 3122 of the coil unit 310 are four flat wire conductors of the coil unit 310. The flat wire conductors are the effective sides of the coil and are the parts embedded in the stator core 200 to play the role of electromagnetic pole energy conversion. The n layers of flat wire conductors can improve the electromagnetic pole energy conversion efficiency.

[0079] The four flat wire conductors of the coil unit 310 are respectively fitted into four winding grooves 220. The n layers of flat wire conductors in each winding groove 220 respectively belong to n coil units 310.

[0080] The groove opening 222 of the winding groove 220 is formed in the inner wall 210 of the stator core 200 facing the rotor. The groove bottom 221 of the winding groove 220 is the bottom wall facing the groove opening 222 of the winding groove 220.

[0081] Exemplarily, n may be 2, 4, 6, 8, 16, or 32.

[0082] In some embodiments, the cross-sectional shape of the flat wire conductor may be rectangular. The rectangular flat wire conductor can improve the groove filling rate.

[0083] In some embodiments, as shown in FIG. 4, n is 8. Exemplarily, the L1 layer to the L8 layer can also be denoted as the a layer, b layer, c layer, d layer, e layer, f layer, g layer, and h layer, respectively.

[0084] In some embodiments, the stator winding 300 includes a plurality of phase windings, each phase winding includes at least one branch circuit, and the branch circuit includes a plurality of coil units 310.

[0085] The number of phase windings may be 2, 3, 4, or 5. Of course, the number of phase windings may also be greater than 5.

[0086] The stator 100 of the embodiments of the present application is applicable to motors with different numbers of phases and can adapt to different voltage and power ranges.

[0087] In some embodiments, the stator winding 300 includes three phase windings, which are the first phase winding, the second phase winding, and the third phase winding, respectively. Optionally, the first phase winding is the U-phase winding, the second phase winding is the V-phase winding, and the third phase winding is the W-phase winding.

[0088] Each phase winding may include only one branch circuit or a plurality of branch circuits. The branch circuit of the phase winding can also be called a parallel-connected branch circuit.

[0089] The number of branch circuits of the phase winding may be any integer, thereby expanding the range of use of the winding design and adapting to different voltage and power ranges.

[0090] In some embodiments, the branch circuit (for example, the branch circuit U1 shown in FIGS. 7 to 17 described later) includes a plurality of coil units 310. In this embodiment, the number of coil units 310 of the branch circuit is not limited.

[0091] If necessary, the number of coil units 310 of the branch circuit can be freely adjusted, thereby expanding the range of use of the winding design and adapting to different voltage and power ranges.

[0092] In some embodiments, the stator winding 300 may be connected as a full pitch winding, a short pitch winding, or a multi-layer winding.

[0093] In some embodiments, in the branch circuit, the flat wire conductors connecting at least two coil units 310 are in the same layer.

[0094] The same layer refers to the order in which the flat wire conductors are stacked within the winding groove 220. For example, the flat wire conductors connecting two coil units 310 to each other are both in layer a or both in layer h.

[0095] Exemplarily, as shown in FIGS. 5 and 6, the second extension 3115 of one coil unit 310 is welded to the second extension 3115 of another coil unit 310, and the second insertion part 3112 of this one coil unit 310 and the second insertion part 3112 of this another coil unit 310 are both flat wire conductors in layer h.

[0096] In the embodiments of the present application, at least two coil units 310 can use full-distance welding and do not require welding across layers, thereby simplifying the welding process. The flat wire conductors connected in the same layer can also balance the groove potential of the branch circuit and reduce the circulating current loss between the branch circuits.

[0097] In some embodiments, in the branch circuit, the L1 layers (for example, the flat wire conductors of layer a) of at least two coil units 310 are connected. The L1 layers of the two coil units 310 are close to the outer ends along the radial direction of the stator core 200, facilitating welding.

[0098] In some embodiments, in the branch circuit, the L n layers (for example, the flat wire conductors of layer h) of at least two coil units 310 are connected. The L n layers of the two coil units 310 are close to the inner ends along the radial direction of the stator core 200, facilitating welding.

[0099] In some embodiments, in the branch circuit, the L1 layers of at least two coil units 310 are connected, and the L n layers of at least two coil units 310 are connected.

[0100] In some embodiments, a first lead wire and a second lead wire are provided at both ends of the branch circuit, and the first lead wire and the second lead wire are connected to different flat wire conductors.

[0101] The flat wire conductor connected to the first lead wire may be a flat wire conductor of any layer, and the flat wire conductor connected to the second lead wire may be a flat wire conductor of any layer, and this embodiment does not limit this.

[0102] The first lead wire and the second lead wire are two connection ends of the branch circuit, and both of them may be used to connect to a bus bar or other members, thereby connecting the branch circuit to an external circuit.

[0103] One of the first lead wire and the second lead wire is a positive electrode lead wire, and the other is a negative electrode lead wire.

[0104] In some embodiments, the flat wire conductors connected to the first lead wire and the flat wire conductors connected to the second lead wire are provided in different winding grooves 220, thereby increasing the distance between the first lead wire and the second lead wire and reducing the risk of the first lead wire and the second lead wire contacting and short - circuiting.

[0105] In some embodiments, the second extension 3115 of the coil unit 310 at the tip of the branch circuit may be used as the first lead wire, and the second extension 3115 of the coil unit 310 at the rear end of the branch circuit may be used as the second lead wire. By using the second extension 3115 of the coil unit 310 as the lead wire, components can be saved, costs can be reduced, and space utilization efficiency can be improved.

[0106] In some embodiments, the flat wire conductor connected to the first lead wire and the flat wire conductor connected to the second lead wire are in the same layer. Exemplarily, both the flat wire conductor connected to the first lead wire and the flat wire conductor connected to the second lead wire are flat wire conductors of layer a.

[0107] This embodiment is advantageous for the arrangement of the bus bar and facilitates the connection between the first lead wire, the second lead wire and the external circuit.

[0108] In some embodiments, the branch circuit includes flat wire conductors of layer k, where k is a positive integer greater than 1. Along the direction in which current flows, the flat wire conductors of layer k are denoted as layer A1, layer A2,..., layer A k-1 layer and A k layer.

[0109] The flat wire conductors of layer k of the branch circuit are connected in series, and the current flows from layer A1 to A k layer in sequence.

[0110] Exemplarily, layer A1 is connected to the first lead wire, and layer A k layer is connected to the second lead wire.

[0111] In some embodiments, any two flat wire conductors that are located within the same winding groove 220 of the branch circuit and adjacent to each other are respectively denoted as the A j layer and the A l layer, where 1 ≦ j < l ≦ k. And l - j ≦ k / 2.

[0112] The greater the difference in the numbers of the flat wire conductors, the greater the differential pressure between the two flat wire conductors. If the difference in the numbers of two flat wire conductors that are located within the same winding groove 220 and adjacent to each other is too large, the voltage stress between the flat wire conductors in the winding groove 220 will become excessive. In the embodiments of the present application, l - j ≦ k / 2 is set, thereby reducing the voltage stress between the flat wire conductors in the winding groove 220.

[0113] In particular, the present embodiment is not limited to adopting the coil unit 310 described above. As long as the difference in the numbers of the flat wire conductors meets the range requirements, the present embodiment may adopt other coil winding methods.

[0114] In some embodiments, the phase winding includes 2P pole-phase groups, where P is a positive integer. Each phase winding includes a plurality of branch circuits, and the plurality of coil units 310 of at least one branch circuit are all distributed among all the pole-phase groups.

[0115] 2P may be the total number of magnetic poles of the stator 100.

[0116] The embodiments of the present application can distribute the plurality of coil units 310 of at least one branch circuit among all the pole-phase groups, thereby reducing the imbalance of the branch circuit potential caused by the eccentricity of the rotor.

[0117] FIG. 7 is a schematic diagram of one branch circuit of the stator according to some embodiments of the present application. FIG. 7 shows one branch circuit U1 of the U-phase winding. Hereinafter, taking the branch circuit U1 as an example, the branch circuit of the stator winding of the present application will be described in detail.

[0118] In Figure 7, N and S represent two magnetic poles of the stator. Exemplarily, the stator has eight magnetic poles, i.e., four pairs of magnetic poles.

[0119] The stator core is provided with 48 winding grooves. In Figure 7, the 48 winding grooves are indicated by the numbers in a row under the N pole and the S pole respectively, i.e., 1 - 48. Each magnetic pole corresponds to six winding grooves.

[0120] Eight flat wire conductors are accommodated in each winding groove. In Figure 7, the eight flat wire conductors are shown as layer a, layer b, layer c, layer d, layer e, layer f, layer g, and layer h respectively.

[0121] The branch circuit U1 includes 16 coil units, i.e., the branch circuit U1 includes 64 flat wire conductors. In Figure 7, the 64 flat wire conductors are indicated by 64 numbers distributed in the table. The 64 flat wire conductors are connected in numerical order. The solid arrows in Figure 7 indicate the connection method at the wire insertion ends of the 64 flat wire conductors, and the dashed arrows represent the connection method at the welding ends of the flat wire conductors. In Figure 7, from 1 to 64, every four flat wire conductors belong to one coil unit.

[0122] Exemplarily, the positive - pole lead wire is the first lead wire, and the negative - pole lead wire is the second lead wire. In Figure 7, U1+ represents the first lead wire, and U1 - represents the second lead wire.

[0123] The first lead wire U1+ is connected to the first flat wire conductor, and the second lead wire U1 - is connected to the 64th flat wire conductor.

[0124] In some embodiments, the coil unit including the 33rd to 36th flat wire conductors is connected to the coil unit including the 29th to 32nd flat wire conductors. Both the 32nd flat wire conductor and the 33rd flat wire conductor are flat wire conductors of layer a. These two coil units can use full-distance welding and do not require welding across layers, thereby simplifying the welding process. The flat wire conductors connected to the same layer can also balance the groove potential of the branch circuit and reduce the circulating current loss between the branch circuits.

[0125] Exemplarily, the coil unit including the 13th to 16th flat wire conductors is connected to the coil unit including the 17th to 20th flat wire conductors. Both the 16th flat wire conductor and the 17th flat wire conductor are flat wire conductors of layer h.

[0126] Exemplarily, the coil unit including the 45th to 48th flat wire conductors is connected to the coil unit including the 49th to 52nd flat wire conductors. Both the 48th flat wire conductor and the 49th flat wire conductor are flat wire conductors of layer h.

[0127] In the branch circuit U1 of the embodiment of the present application, the flat wire conductors of three pairs of coil units adopt same-layer connection, which can balance the groove potential of the branch circuit and reduce the circulating current loss between the branch circuits.

[0128] In some embodiments, the 1st flat wire conductor connected to the first lead wire U1+ is located in the 13th winding groove, and the 64th flat wire conductor connected to the second lead wire U1- is located in the 43rd winding groove.

[0129] In some embodiments, the first flat wire conductor connected to the first lead wire U1+ and the 64th flat wire conductor connected to the second lead wire U1- are both a-layer flat wire conductors. This embodiment is advantageous for the arrangement of the bus bar and facilitates the connection between the first lead wire U1+ and the second lead wire U1- and the external circuit.

[0130] In some embodiments, the stator includes eight magnetic poles, and correspondingly, the phase winding includes eight pole-phase groups. The 16 coils of the branch circuit U1 are distributed among the eight pole-phase groups, which can reduce the imbalance of the branch circuit potential caused by the eccentricity of the rotor.

[0131] In some embodiments, the branch circuit U1 constitutes a full pitch winding.

[0132] In some embodiments, the first flat wire conductor, the 29th flat wire conductor, the 37th flat wire conductor, and the 57th flat wire conductor are stacked in this order in the 13th winding groove. The greater the difference in the numbers of adjacent flat wire conductors, the greater the differential pressure between the two flat wire conductors. In the 13th winding groove, the number difference between the first flat wire conductor and the 29th flat wire conductor is the largest, and the differential pressure between the first flat wire conductor and the 29th flat wire conductor is also the largest. This application can reduce the voltage stress between the flat wire conductors in the winding groove by reasonably setting the coil winding method to make the number difference between any two adjacent flat wire conductors located in the same winding groove in the branch circuit U1 less than 32 (i.e., half of the total number of flat wire conductors in the branch circuit). The winding method shown in FIG. 7 can reduce 57% of the voltage stress in the winding groove.

[0133] FIG. 8 is a schematic diagram of one phase winding of the stator according to some embodiments of this application. Exemplarily, FIG. 8 shows the U-phase winding. Hereinafter, taking the U-phase winding as an example, the stator winding of this application will be described in detail.

[0134] As shown in FIG. 8, the U-phase winding includes a plurality of branch circuits, and two of the plurality of branch circuits are defined as the first branch circuit U1 and the second branch circuit U2.

[0135] For ease of understanding, FIG. 8 divides the first branch circuit U1 and the second branch circuit U2 of the U-phase winding into two tables.

[0136] In FIG. 8, U1+ represents the first lead wire of the first branch circuit U1, U1− represents the second lead wire of the first branch circuit U1, U2+ represents the first lead wire of the second branch circuit U2, and U2− represents the second lead wire of the second branch circuit U2. The meanings of other characters in FIG. 8 can be understood with reference to FIG. 7.

[0137] As shown in FIG. 8, in some embodiments, the plurality of coil units of each branch circuit are distributed among all the pole-phase groups. Specifically, the 16 coil units of the first branch circuit U1 are distributed among 8 pole-phase groups, and the 16 coil units of the second branch circuit U2 are also distributed among 8 pole-phase groups. This embodiment can reduce the imbalance of branch circuit potential due to the eccentricity of the rotor.

[0138] In some embodiments, the plurality of branch circuits of the phase winding may be connected in series or in parallel. Exemplarily, the first branch circuit U1 and the second branch circuit U2 may be connected in series or in parallel.

[0139] In some embodiments, the span between the flat wire conductor connected to the first lead wire of the first branch circuit and the flat wire conductor connected to the first lead wire of the second branch circuit is less than or equal to the pole pitch. The embodiments of the present application can reduce the distance between the first lead wires of the two branch circuits, facilitate the connection of the first lead wires of the two branch circuits, and are advantageous for the arrangement of the bus bar and the implementation of the winding processing process.

[0140] In some embodiments, the flat wire conductors connected to the first lead wire of the first branch circuit and the flat wire conductors connected to the first lead wire of the second branch circuit are provided in the same winding groove. The embodiments of the present application further reduce the distance between the first lead wires of the two branch circuits by drawing out the first lead wires of the two branch circuits from within the same winding groove, facilitating the connection of the first lead wires of the two branch circuits, and being advantageous for the arrangement of the bus bar and the implementation of the winding process.

[0141] As shown in FIG. 8, the first flat wire conductor of the first branch circuit U1 is connected to the first lead wire U1+ of the first branch circuit U1, and the first flat wire conductor of the second branch circuit U2 is connected to the second lead wire U2+ of the second branch circuit U2. Optionally, the first flat wire conductor of the first branch circuit U1 and the first flat wire conductor of the second branch circuit U2 are provided in the same winding groove, i.e., winding groove 13. By drawing out the first lead wires of the two branch circuits from within the same winding groove, the distance between the first lead wires of the two branch circuits is further reduced, facilitating the connection of the first lead wires of the two branch circuits, and being advantageous for the arrangement of the bus bar and the implementation of the winding process.

[0142] In some embodiments, the first flat wire conductor of the first branch circuit U1 and the 64th flat wire conductor of the first branch circuit U1 are both flat wire conductors of layer a, and the first flat wire conductor of the second branch circuit U2 and the 64th flat wire conductor of the second branch circuit U2 are both flat wire conductors of layer h. This embodiment is advantageous for the arrangement of the bus bar and facilitates the connection between the first lead wires (U1+, U2+) and the second lead wires (U1-, U2-) and the external circuit.

[0143] In some embodiments, the 32nd flat wire conductor and the 33rd flat wire conductor of the second branch circuit U2 are both flat wire conductors of the h layer, and the coil unit including the 32nd flat wire conductor and the coil unit including the 33rd flat wire conductor are connected to the same layer. The flat wire conductors connected to the same layer can also balance the groove potential of the branch circuit and reduce the circulating current loss between the branch circuits.

[0144] The U-phase winding shown in FIG. 8 can balance the groove potential of each branch circuit, reduce the circulating current loss between the branch circuits, reduce the imbalance of the electromotive force of the branch circuit due to the eccentricity of the rotor, reduce the voltage stress of the conductor in the groove, and at the same time is advantageous for the arrangement of the bus bar and the implementation of the winding processing process. The U-phase winding shown in FIG. 8 can reduce 57% of the voltage stress in the winding groove.

[0145] FIG. 9 is a schematic diagram of one-phase winding of the stator according to some other embodiments of the present application. Exemplarily, FIG. 9 shows a U-phase winding.

[0146] The meaning of the characters in FIG. 9 can be understood with reference to FIG. 8.

[0147] Compared with the U-phase winding shown in FIG. 8, the U-phase winding shown in FIG. 9 has changed the winding method of the coil.

[0148] As shown in FIG. 9, the 1st flat wire conductor of the 1st branch circuit U1 is connected to the 1st lead wire U1+ of the 1st branch circuit U1, and the 1st flat wire conductor of the 2nd branch circuit U2 is connected to the 2nd lead wire U2+ of the 2nd branch circuit U2.

[0149] In some embodiments, the 1st flat wire conductor of the 1st branch circuit U1 and the 1st flat wire conductor of the 2nd branch circuit U2 are provided in different winding grooves. For example, the 1st flat wire conductor of the 1st branch circuit U1 is provided in the 13th winding groove, and the 1st flat wire conductor of the 2nd branch circuit U2 is provided in the 37th winding groove.

[0150] In some embodiments, the first flat wire conductor of the first branch circuit U1 and the first flat wire conductor of the second branch circuit U2 are both flat wire conductors of the a layer. This embodiment can reduce the distance between the first lead wires of the two branch circuits, facilitate the connection of the first lead wires of the two branch circuits, and is advantageous for the arrangement of the bus bar and the implementation of the winding process.

[0151] In some embodiments, the 64th flat wire conductor of the first branch circuit U1 and the 64th flat wire conductor of the second branch circuit U2 are also both flat wire conductors of the a layer. This embodiment is advantageous for the arrangement of the bus bar and the implementation of the winding process.

[0152] The U-phase winding shown in FIG. 9 can balance the potential of each branch circuit groove, reduce the circulating current loss between the branch circuits, and reduce the imbalance of the electromotive force of the branch circuit due to the eccentricity of the rotor.

[0153] FIG. 10 is a schematic diagram of one phase winding of the stator according to some other embodiments of the present application. Exemplarily, FIG. 10 shows the U-phase winding.

[0154] The meaning of the characters in FIG. 10 can be understood with reference to FIG. 8.

[0155] In some embodiments, the phase winding includes a plurality of branch circuits. The plurality of coil units of each branch circuit are distributed in some pole-phase groups. Specifically, as shown in FIG. 10, the 16 coil units of the first branch circuit U1 are distributed in some pole-phase groups. In other words, the coil units of the first branch circuit U1 are not arranged in some pole-phase groups. The 16 coil units of the second branch circuit U2 are distributed in some pole-phase groups. In other words, the coil units of the second branch circuit U2 are not arranged in some pole-phase groups.

[0156] Exemplarily, the 16 coil units of the first branch circuit U1 are distributed among 4 pole-phase groups, and the 16 coil units of the second branch circuit U2 are distributed among the remaining 4 pole-phase groups.

[0157] In some embodiments, the first flat wire conductor of the first branch circuit U1 and the first flat wire conductor of the second branch circuit U2 are provided in the same winding groove, i.e., winding groove 13. By drawing out the first lead wires of the two branch circuits from within the same winding groove, the distance between the first lead wires of the two branch circuits is further reduced, facilitating the connection of the first lead wires of the two branch circuits, which is advantageous for the arrangement of the bus bar and the implementation of the winding process.

[0158] In some embodiments, the first flat wire conductor of the first branch circuit U1 and the 64th flat wire conductor of the first branch circuit U1 are both flat wire conductors of layer a, and the first flat wire conductor of the second branch circuit U2 and the 64th flat wire conductor of the second branch circuit U2 are both flat wire conductors of layer h.

[0159] In some embodiments, the 16th flat wire conductor of the first branch circuit U1 and the 17th flat wire conductor of the first branch circuit U1 are connected in the same layer. The 48th flat wire conductor of the first branch circuit U1 and the 49th flat wire conductor of the first branch circuit U1 are connected in the same layer. The 32nd flat wire conductor of the second branch circuit U2 and the 33rd flat wire conductor of the second branch circuit U2 are connected in the same layer. The flat wire conductors connected in the same layer can also balance the groove potential of the branch circuit and reduce the circulating current loss between the branch circuits.

[0160] The U-phase winding shown in FIG. 10 can balance the groove potential of each branch circuit, reduce the circulating current loss between the branch circuits, reduce the voltage stress of the conductors in the groove, and is simultaneously advantageous for the arrangement of the bus bar and the implementation of the winding process. The U-phase winding shown in FIG. 10 can reduce 57% of the voltage stress in the winding groove.

[0161] FIG. 11 is a schematic diagram of one-phase winding of a stator according to some other embodiments of the present application. Exemplarily, FIG. 11 shows a U-phase winding.

[0162] The meaning of the characters in FIG. 11 can be understood with reference to FIG. 8.

[0163] As shown in FIG. 11, the 16 coil units of the first branch circuit U1 are distributed in some pole-phase groups, and the 16 coil units of the second branch circuit U2 are distributed in some pole-phase groups.

[0164] In some embodiments, the first flat wire conductor of the first branch circuit U1 and the first flat wire conductor of the second branch circuit U2 are both flat wire conductors of layer a. This embodiment can reduce the distance between the first lead wires of the two branch circuits, facilitate the connection of the first lead wires of the two branch circuits, and is advantageous for the arrangement of the bus bar and the implementation of the winding process.

[0165] In some embodiments, the 64th flat wire conductor of the first branch circuit U1 and the 64th flat wire conductor of the second branch circuit U2 are also both flat wire conductors of layer a. This embodiment is advantageous for the arrangement of the bus bar and the implementation of the winding process.

[0166] In some embodiments, the 16th flat wire conductor of the first branch circuit U1 and the 17th flat wire conductor of the first branch circuit U1 are connected in the same layer. The 32nd flat wire conductor of the first branch circuit U1 and the 33rd flat wire conductor of the first branch circuit U1 are connected in the same layer. The 48th flat wire conductor of the first branch circuit U1 and the 49th flat wire conductor of the first branch circuit U1 are connected in the same layer. The flat wire conductors connected in the same layer can also balance the groove potential of the branch circuit and reduce the circulating current loss between the branch circuits.

[0167] In some embodiments, the 16th flat wire conductor of the second branch circuit U2 and the 17th flat wire conductor of the second branch circuit U2 are connected in the same layer. The 32nd flat wire conductor of the second branch circuit U2 and the 33rd flat wire conductor of the second branch circuit U2 are connected in the same layer. The 48th flat wire conductor of the second branch circuit U2 and the 49th flat wire conductor of the second branch circuit U2 are connected in the same layer. The flat wire conductors connected in the same layer can also balance the groove potential of the branch circuit and reduce the circulating current loss between the branch circuits.

[0168] The U-phase winding shown in FIG. 11 can balance the groove potential of each branch circuit, reduce the circulating current loss between the branch circuits, and is advantageous for the arrangement of the bus bar and the implementation of the winding processing process at the same time.

[0169] FIG. 12 is a schematic diagram of one-phase winding of the stator according to some other embodiments of the present application. Exemplarily, FIG. 12 shows the U-phase winding.

[0170] In some embodiments, the first lead wire may be connected to the flat wire conductor of the intermediate layer, and the second lead wire may be connected to the flat wire conductor of the intermediate layer. Exemplarily, from layer b to layer g may be understood as the intermediate layer. By connecting the lead wire to the flat wire conductor of the intermediate layer, both sides of the lead wire are restricted and supported by the positions of other coils, and the deformation of the lead wire can be reduced.

[0171] In some embodiments, in the same branch circuit, the flat wire conductor connected to the first lead wire and the flat wire conductor connected to the second lead wire are in different layers.

[0172] Exemplarily, as shown in FIG. 12, the first flat wire conductor of the first branch circuit U1 is connected to the first lead wire U1+ of the first branch circuit U1, and the first flat wire conductor of the second branch circuit U2 is connected to the second lead wire U2+ of the second branch circuit U2. Exemplarily, the first flat wire conductor of the first branch circuit U1 may be a flat wire conductor of the c layer, and the first flat wire conductor of the second branch circuit U2 may be a flat wire conductor of the c layer.

[0173] In some embodiments, the 64th flat wire conductor of the first branch circuit U1 may be a flat wire conductor of the b layer, and the 64th flat wire conductor of the second branch circuit U2 may be a flat wire conductor of the b layer.

[0174] Compared with the U-phase winding shown in FIGS. 8 to 11, the U-phase winding shown in FIG. 12 changes the lead wire extraction position, which is advantageous for the arrangement of the bus bar and the implementation of the winding processing process. The U-phase winding shown in FIG. 12 can further balance the potential of each branch circuit groove and reduce the circulating current loss between the branch circuits.

[0175] FIG. 13 is a schematic diagram of one phase winding of the stator according to some other embodiments of the present application. Exemplarily, FIG. 13 shows a U-phase winding.

[0176] The embodiments of the present application do not limit the number of branch circuits of the phase winding, and the number of branch circuits of the phase winding is variable. By changing the number of branch circuits, the motor can be applied to different voltage levels and power ranges.

[0177] Exemplarily, as shown in FIG. 13, the U-phase winding includes four branch circuits, and the four branch circuits are respectively the first branch circuit U1, the second branch circuit U2, the third branch circuit U3, and the fourth branch circuit U4. The four branch circuits can meet the requirements of a low voltage level.

[0178] For ease of understanding, FIG. 13 divides the four branch circuits of the U-phase winding into four tables.

[0179] In FIG. 13, U1+ represents the first lead wire of the first branch circuit U1, U1− represents the second lead wire of the first branch circuit U1, U2+ represents the first lead wire of the second branch circuit U2, U2− represents the second lead wire of the second branch circuit U2, U3+ represents the first lead wire of the third branch circuit U3, U3− represents the second lead wire of the third branch circuit U3, U4+ represents the first lead wire of the fourth branch circuit U4, and U4− represents the second lead wire of the fourth branch circuit U4. The meanings of other characters in FIG. 13 can be understood with reference to FIG. 8.

[0180] As shown in FIG. 13, in some embodiments, the plurality of coil units of each branch circuit are distributed in some pole-phase groups.

[0181] Exemplarily, each branch circuit includes 8 coil units, that is, each branch circuit includes 32 flat wire conductors.

[0182] Exemplarily, the 8 coil units of the first branch circuit U1 are distributed in 2 pole-phase groups, the 8 coil units of the second branch circuit U2 are distributed in 2 pole-phase groups, the 8 coil units of the third branch circuit U3 are distributed in 2 pole-phase groups, and the 8 coil units of the fourth branch circuit U4 are distributed in 2 pole-phase groups.

[0183] In some embodiments, the flat wire conductors connected to the first lead wires of the four branch circuits are in the same layer. Exemplarily, the first flat wire conductor of the first branch circuit U1, the first flat wire conductor of the second branch circuit U2, the first flat wire conductor of the third branch circuit U3, and the first flat wire conductor of the fourth branch circuit U4 are all flat wire conductors of layer a. This embodiment facilitates the connection of the first lead wires of the four branch circuits and is advantageous for the arrangement of the bus bar and the implementation of the winding process.

[0184] In some embodiments, in each branch circuit, the flat wire conductor connected to the first lead wire and the flat wire conductor connected to the second lead wire are in the same layer. Exemplarily, the 32nd flat wire conductor of the first branch circuit U1, the 32nd flat wire conductor of the second branch circuit U2, the 32nd flat wire conductor of the third branch circuit U3, and the 32nd flat wire conductor of the fourth branch circuit U4 are all flat wire conductors in layer a. This embodiment is advantageous for the arrangement of the bus bar and facilitates the connection between the first lead wire, the second lead wire, and the external circuit.

[0185] The U-phase winding shown in FIG. 13 can balance the potential of each branch circuit groove, reduce the circulating current loss between branch circuits, and at the same time change the number of series-connected turns of a single-phase winding, enabling the motor to be applied to different voltage levels and power ranges.

[0186] FIG. 14 is a schematic diagram of one phase winding of the stator according to some other embodiments of the present application. Exemplarily, FIG. 14 shows the U-phase winding.

[0187] The U-phase winding shown in FIG. 14 has a different number of layers of flat wire conductors in the winding groove compared to the U-phase winding shown in FIG. 10. By changing the number of layers of flat wire conductors in the winding groove, the number of series-connected turns of a single-phase winding can be changed, enabling the motor to be applied to different voltage levels and power ranges.

[0188] Exemplarily, as shown in FIG. 14, the number of layers of flat wire conductors in the winding groove is 6.

[0189] Specifically, as shown in FIG. 14, the U-phase winding includes a first branch circuit U1 and a second branch circuit U2. The first branch circuit U1 includes 12 coil units, that is, 48 flat wire conductors. The second branch circuit U2 includes 12 coil units, that is, 48 flat wire conductors.

[0190] In some embodiments, the 12 coil units of the first branch circuit U1 are distributed among some of the pole-phase groups, and the 12 coil units of the second branch circuit U2 are distributed among some of the pole-phase groups.

[0191] The U-phase winding shown in FIG. 14 can balance the potential of each branch circuit groove, reduce the circulating current loss between the branch circuits, and at the same time change the number of series-connected windings of the single-phase winding, enabling the motor to be applied to different voltage levels and power ranges.

[0192] FIG. 15 is a schematic diagram of one phase winding of the stator according to some other embodiments of the present application. Exemplarily, FIG. 15 shows the U-phase winding.

[0193] Compared with the U-phase winding shown in FIG. 11, the phase winding shown in FIG. 15 changes the coil winding method so that the branch circuits of the phase winding form short-distance winding connections, thereby reducing winding harmonics and improving motor torque pulsation and noise vibration.

[0194] The phase winding shown in FIG. 15 can further balance the potential of each branch circuit groove and reduce the circulating current loss between the branch circuits.

[0195] FIG. 16 is a schematic diagram of the stator winding of the stator according to some embodiments of the present application. Exemplarily, FIG. 16 shows the U-phase winding, V-phase winding, and W-phase winding of the stator winding. For ease of understanding, FIG. 16 divides the three-phase winding of the stator winding into three tables.

[0196] In some embodiments, all the first lead wires in the plurality of phase windings are connected to flat wire conductors in different winding grooves. This embodiment can increase the interval between each first lead wire and reduce the voltage stress between phases.

[0197] In some embodiments, all the second lead wires in the plurality of phase windings are connected to flat wire conductors in different winding grooves. This embodiment can increase the interval between each second lead wire and reduce the voltage stress between phases.

[0198] In some embodiments, all the first lead wires and all the second lead wires are connected to flat wire conductors in different winding grooves. This embodiment can increase the spacing between the first lead wires and the second lead wires and reduce the phase-to-phase voltage stress.

[0199] Exemplarily, as shown in FIG. 16, the U-phase winding includes a first branch circuit U1 and a second branch circuit U2. U1+ represents the first lead wire of the first branch circuit U1, U1− represents the second lead wire of the first branch circuit U1, U2+ represents the first lead wire of the second branch circuit U2, and U2− represents the second lead wire of the second branch circuit U2. Optionally, the U-phase winding in FIG. 16 may be formed by combining the first branch circuit U1 and the second branch circuit U2 shown in FIG. 11.

[0200] The V-phase winding includes a first branch circuit V1 and a second branch circuit V2. V1+ represents the first lead wire of the first branch circuit V1, V1− represents the second lead wire of the first branch circuit V1, V2+ represents the first lead wire of the second branch circuit V2, and V2− represents the second lead wire of the second branch circuit V2.

[0201] The W-phase winding includes a first branch circuit W1 and a second branch circuit W2. W1+ represents the first lead wire of the first branch circuit W1, W1− represents the second lead wire of the first branch circuit W1, W2+ represents the first lead wire of the second branch circuit W2, and W2− represents the second lead wire of the second branch circuit W2.

[0202] In some embodiments, the 12 flat wire conductors connected to the lead wires U1+, U1−, U2+, U2−, V1+, V1−, V2+, V2−, W1+, W1−, W2+, W2− are respectively installed in 12 winding grooves. The embodiments of this application can increase the spacing between each lead wire and reduce the phase-to-phase voltage stress. The stator winding shown in FIG. 16 can reduce the phase-to-phase voltage stress by 25%.

[0203] In some embodiments, the twelve flat wire conductors connected to the lead wires U1+, U1-, U2+, U2-, V1+, V1-, V2+, V2-, W1+, W1-, W2+, and W2- are all flat wire conductors of the a layer. The aforementioned lead wires are all close to the outer ends along the radial direction of the stator core, facilitating welding.

[0204] FIG. 17 is a schematic diagram of the stator winding of a stator according to some other embodiments of the present application. Exemplarily, FIG. 17 shows the U-phase winding, V-phase winding, and W-phase winding of the stator winding.

[0205] The meaning of the characters in FIG. 17 can be understood with reference to FIG. 16.

[0206] Exemplarily, the U-phase winding in FIG. 17 may be formed by combining the first branch circuit U1 and the second branch circuit U2 shown in FIG. 10.

[0207] As shown in FIG. 17, in some embodiments, the flat wire conductors connected to the first lead wires U1+ and U2+ are provided in the same winding groove. The flat wire conductors connected to the first lead wires V1+ and V2+ are provided in the same winding groove. The flat wire conductors connected to the first lead wires W1+ and W2+ are provided in the same winding groove. This embodiment can reduce the distance between the first lead wires of two branch circuits of the same phase, facilitate the connection of the first lead wires, and is advantageous for the arrangement of the bus bar and the implementation of the winding processing process.

[0208] FIG. 18 is a schematic diagram of the connection of the phase windings of the stator winding of a stator according to some embodiments of the present application.

[0209] As shown in FIG. 18, in some embodiments, the stator winding includes three phase windings, namely, a U-phase winding, a V-phase winding, and a W-phase winding. Exemplarily, the three phase windings are connected in a triangular shape.

[0210] The U-phase winding includes a first branch circuit U1 and a second branch circuit U2 connected in series. The V-phase winding includes a first branch circuit V1 and a second branch circuit V2 connected in series. The W-phase winding includes a first branch circuit W1 and a second branch circuit W2 connected in series.

[0211] FIG. 19 is a schematic diagram of the connection of the phase windings of the stator winding of the stator according to some other embodiments of the present application.

[0212] As shown in FIG. 19, in some embodiments, the stator winding includes three phase windings, namely, a U-phase winding, a V-phase winding, and a W-phase winding. Exemplarily, the three phase windings are connected in a star shape.

[0213] The U-phase winding includes a first branch circuit U1 and a second branch circuit U2 connected in series. The V-phase winding includes a first branch circuit V1 and a second branch circuit V2 connected in series. The W-phase winding includes a first branch circuit W1 and a second branch circuit W2 connected in series.

[0214] FIG. 20 is a schematic diagram of the connection of the phase windings of the stator winding of the stator according to some other embodiments of the present application.

[0215] As shown in FIG. 20, in some embodiments, the stator winding includes three phase windings, namely, a U-phase winding, a V-phase winding, and a W-phase winding. Exemplarily, the three phase windings are connected in a triangle shape.

[0216] The U-phase winding includes a first branch circuit U1 and a second branch circuit U2 connected in parallel. The V-phase winding includes a first branch circuit V1 and a second branch circuit V2 connected in parallel. The W-phase winding includes a first branch circuit W1 and a second branch circuit W2 connected in parallel.

[0217] FIG. 21 is a schematic diagram of the connection of the phase windings of the stator winding of the stator according to some other embodiments of the present application.

[0218] As shown in FIG. 21, in some embodiments, the stator winding includes three phase windings, namely, a U-phase winding, a V-phase winding, and a W-phase winding. Exemplarily, the three phase windings are connected in a star configuration.

[0219] The U-phase winding includes a first branch circuit U1 and a second branch circuit U2 connected in parallel. The V-phase winding includes a first branch circuit V1 and a second branch circuit V2 connected in parallel. The W-phase winding includes a first branch circuit W1 and a second branch circuit W2 connected in parallel.

[0220] Referring to the different stator windings shown in FIGS. 18 to 21, by changing the connection method of the phase windings and the connection method of the branch circuits of the phase windings, the number of series-connected turns of the stator winding can be adjusted, thereby adapting to applications with different voltage and power levels.

[0221] The embodiments of the present application further provide a flat wire motor, which includes a rotor and a stator according to any one of the foregoing embodiments. The rotor is provided in a space formed and surrounded by the inner wall of the stator core.

[0222] The flat wire motor of the embodiments of the present application may be a generator or a motor.

[0223] The embodiments of the present application further provide a power train including a speed reducer and the above flat wire motor. The flat wire motor is transmission-connected to the speed reducer. Specifically, the drive shaft of the flat wire motor and the input shaft of the speed reducer can be transmission-connected via a transmission member such as a coupling to output the driving force from the flat wire motor to the speed reducer.

[0224] Embodiments of the present application further provide a vehicle, including the above power train, which is installed in the vehicle and provides driving power for the vehicle. Specifically, in this embodiment, the vehicle may be a new energy vehicle specifically driven by electric energy. For example, here, the new energy vehicle may specifically be a hybrid electric vehicle, a pure electric vehicle, a fuel cell electric vehicle, etc., or a vehicle using a high-efficiency accumulator such as a supercapacitor, a flywheel battery, or a flywheel accumulator as the electric energy source.

[0225] According to some embodiments of the present application, referring to FIGS. 1-6, FIG. 11, and FIG. 16, the stator 100 of the flat wire motor includes a stator core 200 and a stator winding 300 installed on the stator core 200. A plurality of winding grooves 220 are formed on the inner wall 210 of the stator core 200, and the plurality of winding grooves 220 are installed along the circumferential direction of the inner wall 210 of the stator core 200. The stator winding 300 includes a U-phase winding, a V-phase winding, and a W-phase winding. Each phase winding includes two branch circuits, and each branch circuit includes a plurality of coil units 310 connected in series.

[0226] Each coil unit 310 includes a first coil 311 and a second coil 312. The first coil 311 includes a first insertion portion 3111, a second insertion portion 3112, a first connection portion 3113, a first extension portion 3114, and a second extension portion 3115. The first connection portion 3113 connects the first insertion portion 3111 and the second insertion portion 3112. The first extension portion 3114 extends from one end of the first insertion portion 3111 away from the first connection portion 3113, and the second extension portion 3115 extends from one end of the second insertion portion 3112 away from the first connection portion 3113.

[0227] The second coil 312 includes a third insertion portion 3121, a fourth insertion portion 3122, a second connection portion 3123, a third extension portion 3124, and a fourth extension portion 3125. The second connection portion 3123 connects the third insertion portion 3121 and the fourth insertion portion 3122. The third extension portion 3124 extends from one end of the third insertion portion 3121 away from the second connection portion 3123, and the fourth extension portion 3125 extends from one end of the fourth insertion portion 3122 away from the second connection portion 3123.

[0228] The first insertion portion 3111, the third insertion portion 3121, the fourth insertion portion 3122, and the second insertion portion 3112 are arranged along the circumferential direction and are respectively inserted into different winding grooves 220. The first insertion portion 3111 is connected to the fourth insertion portion 3122. The second connection portion 3123 is located on one side facing the stator core 200 of the first connection portion 3113.

[0229] The first extension portion 3114 is bent from the first insertion portion 3111 toward the fourth insertion portion 3122. The fourth extension portion 3125 is bent from the fourth insertion portion 3122 toward the first insertion portion 3111 and is connected to the first extension portion 3114.

[0230] It should be noted that unless they conflict, the embodiments and features in this application can be combined with each other.

[0231] Finally, it should be noted that the above embodiments are only for explaining the technical solutions of this application and do not limit it. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that it is still possible to make modifications to the technical solutions described in each of the above embodiments, or perform equivalent substitutions for some of their technical features. However, these modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of each embodiment of this application.

Description of Reference Numerals

[0232] 100 Stator 200 Stator Core 210 Inner wall 220 Coil groove 221 Groove bottom 222 Groove opening 230 Insertion end 240 Protruding end 300 Stator winding 310 Coil unit 311 First coil 312 Second coil 320 Wire insertion end 330 Welding end 3111 First insertion part 3112 Second insertion part 3113 First connection part 3114 First extension part 3115 Second extension part 3121 Third insertion part 3122 Fourth insertion part 3123 Second connection part 3124 Third extension part 3125 Fourth extension part U1 First branch circuit U2 Second branch circuit V1 First branch circuit V2 Second branch circuit W1 First branch circuit W2 Second branch circuit

Claims

1. A stator of a flat wire motor, comprising a stator core and a stator winding installed on the stator core, a plurality of winding grooves are formed on the inner wall of the stator core, and the plurality of winding grooves are installed along the circumferential direction of the inner wall of the stator core, the stator winding includes a plurality of coil units, each coil unit includes a first coil and a second coil, the first coil includes a first insertion part, a second insertion part, and a first connection part connecting the first insertion part and the second insertion part, the second coil includes a third insertion part, a fourth insertion part, and a second connection part connecting the third insertion part and the fourth insertion part, the first insertion part, the third insertion part, the fourth insertion part, and the second insertion part are arranged along the circumferential direction and inserted into different winding grooves respectively, the first insertion part is connected to the fourth insertion part, and the second connection part is located on one side of the first connection part facing the stator core, a stator of a flat wire motor.

2. The first coil further includes a first extension part and a second extension part, the first extension part extends from one end of the first insertion part away from the first connection part, and the second extension part extends from one end of the second insertion part away from the first connection part, the second coil further includes a third extension part and a fourth extension part, the third extension part extends from one end of the third insertion part away from the second connection part, and the fourth extension part extends from one end of the fourth insertion part away from the second connection part, the first extension part is bent toward the fourth insertion part with respect to the first insertion part, and the fourth extension part is bent toward the first insertion part with respect to the fourth insertion part and connected to the first extension part, the stator according to claim 1.

3. The number of the winding grooves is 12·M, where M is a positive integer, the span between the first insertion part and the second insertion part of the first coil is 7 winding grooves, and the span between the third insertion part and the fourth insertion part of the second coil is 5 winding grooves, the stator according to claim 1 or 2.

4. The first insertion part, the third insertion part, the fourth insertion part, and the second insertion part serve as flat wire conductors in the corresponding winding grooves respectively, The flat wire conductors in each of the winding grooves are arranged in n layers, where n is a positive even number, and the n layers of the flat wire conductors are arranged in a direction from the bottom of the winding groove to the opening of the winding groove. １ layer,. .. .. .. .. .. , L ｉ layer, ... and L ｎ 4. The stator according to claim 1, wherein i is a layer and 1≦i≦n is a layer.

5. The stator winding includes a plurality of phase windings, each of the phase windings includes at least one branch circuit, and the branch circuit includes a plurality of the coil units. In the branch circuit, the flat wire conductors connected to each other of at least two of the coil units are in the same layer. The stator according to claim 4.

6. In the branching circuit, the L of at least two of the coil units is １ layers are connected, and / or In the branching circuit, L of at least two of the coil units ｎ layers are connected, the stator according to claim 5.

7. The stator winding includes a plurality of phase windings, each of the phase windings includes at least one branch circuit, and the branch circuit includes a plurality of the coil units. A first lead wire and a second lead wire are provided at both ends of the branch circuit. The first lead wire and the second lead wire are connected to different flat wire conductors, and the flat wire conductors connected to the first lead wire and the flat wire conductors connected to the second lead wire are provided in different winding grooves. The stator according to any one of claims 4 to 6.

8. The flat wire conductor connected to the first lead wire and the flat wire conductor connected to the second lead wire are in the same layer. The stator according to claim 7.

9. Each of the phase windings includes a plurality of the branch circuits. Two of the plurality of branch circuits are used as a first branch circuit and a second branch circuit. The span between the flat wire conductor connected to the first lead wire of the first branch circuit and the flat wire conductor connected to the first lead wire of the second branch circuit is equal to or less than the pole pitch. The stator according to claim 7 or 8.

10. The flat wire conductor connected to the first lead wire of the first branch circuit and the flat wire conductor connected to the first lead wire of the second branch circuit are provided in the same winding groove. The stator according to claim 9.

11. All the first lead wires in the plurality of phase windings are connected to the flat wire conductors in different winding grooves. The stator according to any one of claims 7 to 9.

12. The stator winding includes a plurality of phase windings, each of the phase windings includes at least one branch circuit, and the branch circuit includes a plurality of the coil units. The branch circuit includes the k-layer flat wire conductors, where k is a positive integer greater than 1, and along the direction in which current flows, the k-layer flat wire conductors are designated as A １ layer, A ２ Layer....., A ｋ－１ Layer and A ｋ denoted as layer, Any two adjacent flat wire conductors located in the same winding groove of the branch circuit and denoted as layer A and layer A respectively, where 1 ≦ j < l ≦ k and l - j ≦ k / 2. The stator according to any one of claims 4 to 11. ｊ layer and A ｌ layer, and the stator according to any one of claims 4 to 11, where 1 ≦ j < l ≦ k and l - j ≦ k / 2.

13. The stator winding includes a plurality of phase windings, each of the phase windings includes at least one branch circuit, and the branch circuit includes a plurality of the coil units. The phase winding includes 2P pole-phase groups, where P is a positive integer, Each of the phase windings includes a plurality of the branch circuits, and the plurality of coil units of at least one of the branch circuits are distributed among all of the pole-phase groups. The stator according to any one of claims 1 to 12. **Claim 14** The stator winding includes a plurality of phase windings, each of the phase windings includes at least one branch circuit, and the branch circuit includes a plurality of the coil units, The phase winding includes 2P pole-phase groups, where P is a positive integer, Each of the phase windings includes a plurality of the branch circuits, and the plurality of coil units of each of the branch circuits are distributed among some of the pole-phase groups. The stator according to any one of claims 1 to 12. **Claim 15** A flat wire motor including a rotor and the stator according to any one of claims 1 to 14, wherein the rotor is provided in a space formed and surrounded by the inner wall of the stator core. The flat wire motor.

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