Stator assembly and electric machine

Abstract

The present application relates to a kind of stator assembly, motor and electric drive system, stator assembly includes: stator core, with multiple stator teeth and the stator tooth slot formed between stator tooth, the number of stator tooth slot is 54, stator core is defined with an axis;Stator winding, a part is located in stator tooth slot, made of multiple cross section rectangular conductor element, conductor element is arranged with 6 layers in each tooth slot, and stator winding includes U phase winding, V phase winding and W phase winding, and the winding mode of each phase winding is same, the layer farthest from the axis is the 1st layer, the layer closest to the axis is the 6th layer, other layers are sequentially arranged between the 1st layer and the 6th layer, each phase winding has 3 parallel branches, and for stator winding, the span it contains only 4 kinds.The present application improves the high-speed power of motor, facilitates busbar and outlet terminal design, reduces the process complexity of stator winding and avoids the in-phase circulation.

Description

Technical Field

[0001] This invention relates to the field of motor technology, specifically to a stator assembly and a motor. Background Technology

[0002] For drive motors, their power performance is extremely important to the performance of vehicles. To improve the power performance of drive motors, flat wire motors have a natural advantage over motors with windings formed by conductors with circular cross-sections. Because their windings use conductors with rectangular cross-sections, the conductors can be closely arranged inside the slots, achieving a higher slot fill factor, thereby increasing the motor's power density and reducing its thermal load.

[0003] A key design consideration for flat-wire motors is arranging the two basic components, U-pin and I-pin, to form different windings. The applicant has proposed several different winding designs for flat-wire motors, and various other winding designs proposed by other applicants also exist in this field. Due to varying requirements, and the differences in electrical performance, conductor quantity and specifications, manufacturing processes, and busbar manufacturing processes resulting from different winding methods, the winding design of flat-wire motors remains an area where new solutions are constantly emerging.

[0004] For a 6-pole 54-slot motor, among the solutions known to the applicant, there are already 4 / 6 / 8 / 10 layer designs with 1 or 2 parallel windings. Such designs have a high number of winding turns, which makes it difficult to increase the high-speed power of the motor. Summary of the Invention

[0005] In view of the above, the present invention proposes the following technical solution.

[0006] A stator assembly, comprising:

[0007] A stator core having a plurality of stator teeth and stator slots formed between the stator teeth, the number of stator slots being 54, and the stator core defining an axis;

[0008] The stator winding, a portion of which is located within the stator slots, is made of multiple conductor elements with rectangular cross-sections. Six layers of conductor elements are arranged within each slot. The stator winding includes U-phase, V-phase, and W-phase windings, with each phase winding having the same winding method. The layer furthest from the axis is layer 1, and the layer closest to the axis is layer 6. The other layers are arranged sequentially between layers 1 and 6.

[0009] Each phase winding has three parallel branches, and for the stator winding, there are only four possible spans.

[0010] According to one example of the invention, each branch of each phase winding has 6 winding cycles, and in each winding cycle, the conductor element of the branch is located in 6 stator slots. For each branch of each phase winding, the conductor element located in the 6 stator slots has 5 spans, wherein the 1st, 3rd, and 5th spans are all 9, and the 2nd and 4th spans are both 8 or 9.

[0011] According to one example of the invention, for each branch of each phase winding, the layer in which the conductor element is located changes sequentially between the 1st and 6th layers within each cycle, and the changing trend of the layer in which the conductor element is located is opposite in two adjacent cycles.

[0012] According to one example of the invention, for each branch of each phase winding, within each cycle, the slot number of each conductor element changes in the same direction, and the trend of change of the slot number of each conductor element within each cycle is opposite to the trend of change of the slot number of each conductor element within the adjacent cycle.

[0013] According to one example of the present invention, for each branch of each phase, in these 6 cycles, the span variation pattern of the cycles with odd-numbered cycle numbers is the same, which is 9-9-9-8-9, and the span variation pattern of the cycles with even-numbered cycle numbers is the same, which is 9-8-9-9-9.

[0014] According to one example of the invention, in the six cycles of the first branch of each phase, as the span changes from one cycle to the next, the span is successively 9-10-9-7-9; and / or

[0015] In the six cycles of the second branch of each phase, when changing from one cycle to the next, the span is successively 9-7-9-10-9; and / or

[0016] In the 6 cycles of the third branch of each phase, when changing from one cycle to the next, the span is 9-10-9-10-9.

[0017] According to one example of the invention, the stator windings can self-cross between the first layer in two ways: across 10 and across 7;

[0018] There is only one way to cross a line between layers 1 and 2, between layers 2 and 3, between layers 3 and 4, between layers 5 and 6, and between layers 6: cross 9.

[0019] There is one way to cross lines between the 4th and 5th floors: cross 8.

[0020] Each phase winding, after entering the line, follows this pattern, crossing the line 6 times before exiting the line.

[0021] According to one example of the invention, the winding is a short-pitch winding.

[0022] The present invention also proposes an electric motor, including a rotor assembly and a stator assembly, wherein the stator assembly adopts the stator assembly described above.

[0023] The present invention also proposes an electric drive system, including at least one of a reducer and an inverter, and the aforementioned motor.

[0024] As can be seen from the above, the present invention proposes a 54-slot, 6-layer stator winding, which has the following advantages:

[0025] (1) The use of a three-way parallel branch design improves the high-speed power of the motor;

[0026] (2) The leads are on the same side of the winding and concentrated at the hairpin end, which facilitates the design of the busbar and the outgoing terminal and reduces the manufacturing complexity of the stator winding and the busbar connected to it.

[0027] (3) Only 5 types of U-shaped pins and 1 type of special lead-out pin are required for the conductor components, which reduces the complexity of wire forming and insertion processes. The lead-out pins at the hairpin end are easy to weld and automate production.

[0028] (4) By designing the arrangement of three pairs of pole windings for each phase, the potential balance is achieved and the internal circulation current within the phase is avoided.

[0029] Other features and advantages of the present invention will be described in detail below with reference to the accompanying drawings. Attached Figure Description

[0030] Exemplary embodiments of the present invention are described with reference to the accompanying drawings, wherein:

[0031] Figure 1 A perspective view of a stator winding according to an embodiment of the present invention is shown.

[0032] Figure 2 A front sectional view of a stator assembly according to an embodiment of the present invention is shown.

[0033] Figure 3 A schematic diagram of the three-phase, three-path parallel connection of the stator winding of the present invention is shown.

[0034] Figure 4 A schematic diagram of the stator winding layout of the present invention is shown.

[0035] Figure 5 The U-phase unfolded design diagram of the stator winding of the present invention is shown.

[0036] Figure 6 The diagram shows the V-phase unfolded design of the stator winding of the present invention.

[0037] Figure 7 The W-phase unfolded design diagram of the stator winding of the present invention is shown.

[0038] All accompanying drawings are schematic only and are not necessarily drawn to scale. Furthermore, they only show those parts necessary to illustrate the invention; other parts are omitted or merely mentioned. That is, the invention may include other parts besides those shown in the drawings.

[0039] In the accompanying drawings, the same and / or functionally identical technical features are represented by the same or similar reference numerals. Detailed Implementation

[0040] Embodiments of the present invention are described below with reference to the accompanying drawings. In the following description, numerous specific details are set forth to enable those skilled in the art to more fully understand and implement the invention. However, it will be apparent to those skilled in the art that implementations of the invention may not include some of these specific details. Furthermore, it should be understood that the invention is not limited to the specific embodiments described. Rather, the invention can be conceived to be practiced with any combination of the features and elements described below, regardless of whether they relate to different embodiments. Therefore, the following aspects, features, embodiments, and advantages are for illustrative purposes only and should not be construed as features or limitations of the claims unless expressly set forth in the claims.

[0041] The descriptions of orientation used in the following description, such as “upper,” “lower,” “inner,” “outer,” “radial,” and “axial,” are merely for convenience of description and are not intended to limit the technical solution of the invention unless explicitly stated otherwise. Furthermore, the terms “first,” “second,” and other similar terms used below to describe the elements of this application are only used to distinguish individual elements and are not intended to limit the nature, sequence, order, or number of these elements.

[0042] Figure 1 A perspective view of a stator winding according to an embodiment of the present invention is shown. The stator winding 20 is formed by welding together a plurality of conductor elements arranged in a manner described in detail below. The conductor elements include U-shaped conductor elements. Figure 1 In the final stator winding 20, the overall shape is cylindrical, thereby defining an axis. The stator winding 20 has a first end 21 at the lower end shown in the figure, where multiple conductor elements are welded together in a predetermined arrangement, while the other end of the U-shaped conductor elements forms a second end at the upper end of the figure, also known as a crown end based on its shape.

[0043] In actual assembly, one feasible process is to first twist the heads of multiple conductor elements to their predetermined positions, then insert their legs into the slots of the stator, followed by bending and welding. Alternatively, other processes known in the prior art can be used to form the stator winding 20.

[0044] After the stator winding 20 is formed in the stator to form a stator assembly, the first end 21 and the second end 22 of the stator winding 20 are located outside the stator in the axial direction, while the portion of the stator winding 20 located between the first end 21 and the second end 22 is located inside the stator in the axial direction, specifically inside the slots of the stator.

[0045] To connect the stator windings to other components such as the inverter, the stator windings also have leads 23. Leads 23 include multiple leads that are connected to the inverter via busbars to receive three-phase alternating power to generate an alternating magnetic field in the stator, thereby causing the rotor located inside the stator to rotate.

[0046] As one aspect of the present invention, such as Figure 1 As shown, all leads of the stator winding 100 at the lead-out terminal 40 are located on the outermost radial side of the stator winding. The following section will describe how to implement this structure in conjunction with specific winding methods.

[0047] Figure 2 A front sectional view of a stator assembly according to an embodiment of the present invention is shown. Figure 2 As shown, the stator of the present invention has 54 slots, and six layers of conductor elements are arranged in each slot. Figure 2 In the diagram, one phase winding is represented by one color, while the other two phase windings are represented by a different color.

[0048] Figure 3 A schematic diagram of a three-phase, three-way parallel stator winding according to the present invention is shown. For stator windings, if a 4 / 6 / 8 / 10-layer design with one or two parallel windings is used, the number of winding turns is high, making it difficult to increase the high-speed power of the motor. Therefore, the present invention proposes a stator winding scheme based on a three-way parallel connection.

[0049] Specifically, for the three-phase parallel scheme, for the three-phase windings including U phase, V phase and W phase, the structure of each phase is the same, and the windings of each phase are 120° apart on the circumference.

[0050] like Figure 3As can be seen, for phases U, V, and W, each phase includes three branches connected in parallel. Taking phase U as an example, each branch includes input terminals U1in, U2in, and U3in, and output terminals U1out, U2out, and U3out. Between the input and output terminals of each branch are multiple conductor elements connected in sequence. As mentioned earlier, for flat wire motors, winding design is crucial. Different winding designs affect the motor's electrical performance, the specifications and number of conductor elements, manufacturing processes, and the manufacturing process of the busbars connected to the windings.

[0051] Therefore, this application proposes the following winding design. Since there is a correspondence between the three phases, the following explanation uses the U-phase winding as an example, showing the position of each conductor element in each branch and their interconnections. Specifically, for the position of each conductor element, m(n) represents its position in the stator slot, where m represents the slot number and n represents the layer number within a slot. For this application, the proposed stator winding is for a stator with 54 slots, and each slot has 6 layers. The layer numbers increase sequentially from the inside out within the slot; that is, within each slot, the deepest layer is numbered 1, and the outermost layer, or the layer closest to the rotor, is numbered 6.

[0052] According to the above rules, a specific example of a winding design proposed in this application is as follows.

[0053] For the first branch, the positions and specific connections of its conductor elements are as follows:

[0054] U1_in→

[0055] 46(1)→37(2)→28(3)→19(4)→11(5)→2(6)→

[0056] 47(6)→2(5)→10(4)→19(3)→28(2)→37(1)→

[0057] 27(1)→18(2)→9(3)→54(4)→46(5)→37(6)→

[0058] 28(6)→37(5)→45(4)→54(3)→9(2)→18(1)→

[0059] 11(1)→2(2)→47(3)→38(4)→30(5)→21(6)→

[0060] 12(6)→21(5)→29(4)→38(3)→47(2)→2(1)→

[0061] U1_out.

[0062] Since the slot numbering is relative, the numbering of the same slot can change as long as the slot numbers of all the slots in the entire stator are consecutive. Therefore, the positions of the conductor elements in the U-phase stator winding described above are merely an example. Even after changing the slot numbering, as long as the relative positions of the conductor elements remain the same, the same stator winding can still be obtained. Based on the above example, the core principle of the first branch of the stator winding proposed in this invention is as follows:

[0063] (1) The first branch consists of 6 winding cycles. As shown in the winding relationship above, each row represents one winding cycle. Within each winding cycle, the conductor element in the winding is located in one of the 6 slots. Within each cycle, the layer of the conductor element changes sequentially between layer 1 and layer 6. Furthermore, in two adjacent cycles, the changing trend of the layer of the conductor element is opposite. For example, in the first cycle, the number of layers changes from layer 1 to layer 6, while in the second cycle, the number of layers changes from layer 6 to layer 1, and in the third cycle, the number of layers changes again from layer 1 to layer 6.

[0064] (2) Within each cycle, the slot numbering of each conductor element changes in the same direction. Furthermore, the trend of slot numbering for each conductor element within each cycle is opposite to the trend of slot numbering for each conductor element in adjacent cycles. For example, in the first cycle, the slot numbers of the conductor elements are 46→37→28→19→11→2. If the direction of slot numbering is defined as counterclockwise or the first direction, then the slot numbers of the conductor elements in the second cycle are 47→2→10→19→28→37, meaning the direction of slot numbering is clockwise or the second direction. In the first branch, the slot numbering of the conductor elements in the 1st, 3rd, and 5th cycles follows the first direction, while the slot numbering of the conductor elements in the 2nd, 4th, and 6th cycles follows the second direction.

[0065] (3) Since the conductor elements contained in each cycle are distributed in 6 slots, the number of slots between two adjacent conductor elements is defined as the span. Then, in all 6 cycles, each cycle contains 5 spans, and the values ​​of the 1st, 3rd, and 5th spans are the same in all 6 cycles. Furthermore, the values ​​of the 1st, 3rd, and 5th spans are all 9.

[0066] Furthermore, the second and fourth spans within each cycle are both 8 or 9.

[0067] (4) In these 6 cycles, when changing from one cycle to the next, the span is 9-10-9-7-9 in sequence.

[0068] (5) In these 6 cycles, the span variation pattern is the same for cycles with odd-numbered cycles and the span variation pattern is the same for cycles with even-numbered cycles. Furthermore, the spans in each cycle are 9-9-9-8-9, 9-8-9-9-9, 9-9-9-8-9, 9-8-9-9-9, 9-9-9-8-9, and 9-8-9-9-9.

[0069] For the second branch, the positions and specific connections of its conductor elements are as follows:

[0070] U2_in→

[0071] 45(1)→36(2)→27(3)→18(4)→10(5)→1(6)→

[0072] 46(6)→1(5)→9(4)→18(3)→27(2)→36(1)→

[0073] 29(1)→20(2)→11(3)→2(4)→48(5)→39(6)→

[0074] 30(6)→39(5)→47(4)→2(3)→11(2)→20(1)→

[0075] 10(1)→1(2)→46(3)→37(4)→29(5)→20(6)→

[0076] 11(6)→20(5)→28(4)→37(3)→46(2)→1(1)→

[0077] U2_out.

[0078] The core principle of the second branch of the stator winding proposed in this invention is as follows:

[0079] (1) The second branch consists of 6 winding cycles. As shown in the winding relationship above, each row represents one winding cycle. Within each winding cycle, the conductor element in the winding is located in one of the 6 slots. Within each cycle, the layer of the conductor element changes sequentially between layer 1 and layer 6. Furthermore, in two adjacent cycles, the changing trend of the layer of the conductor element is opposite. For example, in the first cycle, the number of layers changes from layer 1 to layer 6, while in the second cycle, the number of layers changes from layer 6 to layer 1, and in the third cycle, the number of layers changes again from layer 1 to layer 6.

[0080] (2) Within each cycle, the slot numbering of each conductor element changes in the same direction. Furthermore, the trend of slot numbering for each conductor element within each cycle is opposite to the trend of slot numbering for each conductor element in adjacent cycles. For example, in the first cycle, the slot numbers of the conductor elements are 45→36→27→18→10→1. If the direction of slot numbering is defined as counterclockwise or the first direction, then in the second cycle, the slot numbers of the conductor elements are 46→1→9→18→27→36, meaning the direction of slot numbering is clockwise or the second direction. In the first branch, the slot numbering of the conductor elements in the 1st, 3rd, and 5th cycles follows the first direction, while the slot numbering of the conductor elements in the 2nd, 4th, and 6th cycles follows the second direction.

[0081] (3) Since the conductor elements contained in each cycle are distributed in 6 slots, the number of slots between two adjacent conductor elements is defined as the span. Then, in all 6 cycles, each cycle contains 5 spans, and the values ​​of the 1st, 3rd, and 5th spans are the same in all 6 cycles. Furthermore, the values ​​of the 1st, 3rd, and 5th spans are all 9.

[0082] Furthermore, the second and fourth spans within each cycle are both 8 or 9.

[0083] (4) In these 6 cycles, when changing from one cycle to the next, the span is 9-7-9-10-9 in sequence.

[0084] (5) In these 6 cycles, the span variation pattern is the same for cycles with odd-numbered cycles and the span variation pattern is the same for cycles with even-numbered cycles. Furthermore, the spans in each cycle are 9-9-9-8-9, 9-8-9-9-9, 9-9-9-8-9, 9-8-9-9-9, 9-9-9-8-9, and 9-8-9-9-9.

[0085] For the third branch, the positions and specific connections of its conductor elements are as follows:

[0086] U3_in→

[0087] 47(1)→38(2)→29(3)→20(4)→12(5)→3(6)→

[0088] 48(6)→3(5)→11(4)→20(3)→29(2)→38(1)→

[0089] 28(1)→19(2)→10(3)→1(4)→47(5)→38(6)→

[0090] 29(6)→38(5)→46(4)→1(3)→10(2)→19(1)→

[0091] 9(1)→54(2)→45(3)→36(4)→28(5)→19(6)→

[0092] 10(6)→19(5)→27(4)→36(3)→45(2)→54(1)→

[0093] U3_out.

[0094] The core principle of the third branch of the stator winding proposed in this invention is as follows:

[0095] (1) The third branch consists of 6 winding cycles. As shown in the winding relationship above, each row represents one winding cycle. Within each winding cycle, the conductor element in the winding is located in one of the 6 slots. Within each cycle, the layer of the conductor element changes sequentially between layer 1 and layer 6. Furthermore, in two adjacent cycles, the changing trend of the layer of the conductor element is opposite. For example, in the first cycle, the number of layers changes from layer 1 to layer 6, while in the second cycle, the number of layers changes from layer 6 to layer 1, and in the third cycle, the number of layers changes again from layer 1 to layer 6.

[0096] (2) Within each cycle, the slot numbering of each conductor element changes in the same direction. Furthermore, the trend of slot numbering for each conductor element within each cycle is opposite to that of the adjacent cycle. For example, in the first cycle, the slot numbers of the conductor elements are 47→38→29→20→12→3. If the direction of slot numbering is defined as counter-clockwise or the first direction, then in the second cycle, the slot numbers of the conductor elements are 48→3→11→20→29→38, meaning the direction of slot numbering is clockwise or the second direction. In the first branch, the slot numbering of the conductor elements in the 1st, 3rd, and 5th cycles follows the first direction, while the slot numbering of the conductor elements in the 2nd, 4th, and 6th cycles follows the second direction.

[0097] (3) Since the conductor elements contained in each cycle are distributed in 6 slots, the number of slots between two adjacent conductor elements is defined as the span. Then, in all 6 cycles, each cycle contains 5 spans, and the values ​​of the 1st, 3rd, and 5th spans are the same in all 6 cycles. Furthermore, the values ​​of the 1st, 3rd, and 5th spans are all 9.

[0098] Furthermore, the second and fourth spans within each cycle are both 8 or 9.

[0099] (4) In these 6 cycles, when changing from one cycle to the next, the span is 9-10-9-10-9 in sequence.

[0100] (5) In these 6 cycles, the span variation pattern is the same for cycles with odd-numbered cycles and the span variation pattern is the same for cycles with even-numbered cycles. Furthermore, the spans in each cycle are 9-9-9-8-9, 9-8-9-9-9, 9-9-9-8-9, 9-8-9-9-9, 9-9-9-8-9, and 9-8-9-9-9.

[0101] As illustrated. Figure 4 This diagram shows the unfolded design of the stator winding of the present invention. Figure 5 This diagram shows the U-phase unfolded design of the stator winding of the present invention. Figure 6 This diagram shows the V-phase unfolded design of the stator winding of the present invention. Figure 7 The W-phase unfolded design diagram of the stator winding of the present invention is shown. Figure 5 The U-phase unfolded diagram shown corresponds to the slot number and layer number of the conductor element described above. Figure 6 , Figure 7 The arrangement can be obtained according to the above-described layout.

[0102] As can be seen from the above, in the winding connection method according to the present invention, the span after the winding input includes only four types: 7, 8, 9, and 10. Specifically, the span between layers meets the following conditions:

[0103] There are two ways to cross lines between layers 1: crossing 10 and crossing 7;

[0104] There is only one way to cross between layers 1 and 2 (including from layer 1 to layer 2 and from layer 2 to layer 1): cross 9.

[0105] There is one way to cross between the 2nd and 3rd floors (including from the 2nd floor to the 3rd floor and from the 3rd floor to the 2nd floor): cross 9;

[0106] There is one way to cross between the 3rd and 4th floors (including from the 3rd floor to the 4th floor and from the 4th floor to the 3rd floor): cross 9.

[0107] There is one way to cross between the 4th and 5th floors (including from the 4th floor to the 5th floor and from the 5th floor to the 4th floor): cross 8 floors;

[0108] There is one way to cross between the 5th and 6th floors (including from the 5th floor to the 6th floor and from the 6th floor to the 5th floor): cross 9.

[0109] There is one type of self-crossing method between the 6th layer: crossing 9.

[0110] After the incoming wires are connected, the entire single-phase winding follows this pattern, crossing the wires for 6 turns before exiting the winding.

[0111] As shown above, for the entire winding, the span of 9 appears most frequently, followed by 8, 7, and 10. This means that for the entire winding, only 5 different U-shaped conductor elements and 1 conductor element used as a lead wire are needed to form the entire winding. Therefore, the manufacturing complexity of the stator winding is reduced. At the same time, the simplicity and uniformity of the jumper type also reduces the complexity of the overmolding process, decreasing the costs of copper wire bending and injection molding.

[0112] Furthermore, for the windings of the present invention, both the input and output ends are on the same side and in the first layer, which simplifies the structural design of the busbar and makes the connection structure between the busbar and the stator winding simpler.

[0113] In addition to manufacturing advantages, the stator winding of this invention also offers advantages in electrical performance. Specifically, due to its short-pitch design, the stator winding of this invention reduces the coil span, weakens high-order harmonic components, and lowers leakage flux and electromagnetic noise, thereby reducing the motor's NVH and decreasing the design costs for subsequent NVH optimization. Furthermore, the arrangement of three pole pairs of windings per phase ensures potential balance and avoids intra-phase circulating currents.

[0114] The motor with the stator winding of this application can be used in various types of electric vehicles. For example, it can be used in pure electric vehicles that are powered solely by batteries, or in hybrid vehicles that include other types of power sources besides the motor.

[0115] The present invention has been clearly and completely described with reference to the illustrative embodiments above. Those skilled in the art should understand that various other embodiments can be conceived through modifications to the disclosed technical solutions without departing from the spirit and scope of the invention. These embodiments should be understood to fall within the scope of the present invention as defined by the claims and any equivalent technical solutions.

Claims

1. A stator assembly, comprising: A stator core having a plurality of stator teeth and stator slots formed between the stator teeth, the number of stator slots being 54, and the stator core defining an axis; The stator winding, a portion of which is located within the stator slots, is made of multiple conductor elements with rectangular cross-sections. Six layers of conductor elements are arranged within each slot. The stator winding includes U-phase, V-phase, and W-phase windings, with each phase winding having the same winding method. The layer furthest from the axis is layer 1, and the layer closest to the axis is layer 6. The other layers are arranged sequentially between layers 1 and 6. Its features are, Each phase winding has three parallel branches, and for the stator winding, there are only four possible spans.

2. The stator assembly according to claim 1, characterized in that, For each branch of each phase winding, there are 6 winding cycles. In each winding cycle, the conductor element of the branch is located in 6 stator slots. For each branch of each phase winding, the conductor element located in the 6 stator slots has 5 spans, of which the 1st, 3rd and 5th spans are all 9, and the 2nd and 4th spans are both 8 or 9.

3. The stator assembly according to claim 2, characterized in that, For each branch of each phase winding, within each cycle, the layer where the conductor element is located changes sequentially between layer 1 and layer 6, and within two adjacent cycles, the changing trend of the layer where the conductor element is located is opposite.

4. The stator assembly according to claim 2 or 3, characterized in that, For each branch of each phase winding, within each cycle, the slot number of each conductor element changes in the same direction, and the trend of the change of the slot number of each conductor element within each cycle is opposite to the trend of the change of the slot number of each conductor element within the adjacent cycle.

5. The stator assembly according to any one of claims 2-4, characterized in that, For each branch of each phase, in these 6 cycles, the span variation pattern of the cycles with odd-numbered cycles is the same, which is 9-9-9-8-9, and the span variation pattern of the cycles with even-numbered cycles is the same, which is 9-8-9-9-9.

6. The stator assembly according to claim 5, characterized in that, In the first branch of each phase, during the six cycles, as the span changes from one cycle to the next, the spans are 9-10-9-7-9 respectively; and / or In the six cycles of the second branch of each phase, when changing from one cycle to the next, the span is successively 9-7-9-10-9; and / or In the 6 cycles of the third branch of each phase, when changing from one cycle to the next, the span is 9-10-9-10-9.

7. The stator assembly according to any one of claims 1-6, characterized in that, The stator windings can cross over each other in two ways between the first layer: crossing 10 and crossing 7. There is only one way to cross a line between layers 1 and 2, between layers 2 and 3, between layers 3 and 4, between layers 5 and 6, and between layers 6: cross 9. There is one way to cross lines between the 4th and 5th floors: cross 8. After each phase winding enters the circuit, it exits the circuit after crossing the wire 6 times according to this rule.

8. The stator assembly according to any one of claims 1-7, characterized in that, The winding is a short-pitch winding.

9. An electric motor comprising a rotor assembly and a stator assembly according to any one of claims 1-8.

10. An electric drive system, comprising at least one of a reducer and an inverter, characterized in that, It also includes the motor according to claim 9.

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