Stator assembly and electric machine

Abstract

The application discloses a stator assembly and a motor. The stator assembly comprises a stator core and a stator winding. The stator core has a plurality of stator slots formed on a radially inner surface of the stator core and spaced apart along a circumferential direction of the stator core at a predetermined slot pitch. The stator winding comprises a plurality of phase windings mounted on the stator core and forms M layers on each stator slot, where M is an odd number greater than or equal to 3. Each phase winding comprises a plurality of coil units connected in series. Each coil unit comprises a first U-shaped hairpin winding, an I-shaped hairpin winding and a second U-shaped hairpin winding. The first U-shaped hairpin winding is located at an innermost layer of the stator slot, the I-shaped hairpin winding is located at a middle layer of the stator slot, and the second U-shaped hairpin winding is located at an outermost layer of the stator slot. The opening direction of the first U-shaped hairpin winding and the second U-shaped hairpin winding is opposite. The stator assembly of the application avoids same-layer welding, greatly simplifies the process steps and reduces the welding difficulty.

Description

Technical Field

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

[0002] Hairpin motors are widely used in new energy vehicles due to their advantages of higher slot fill factor, shorter winding ends, higher power density, and stronger heat dissipation. Hairpin motors can be divided into two types according to the number of layers of their pin hairpin coils: even-layer and odd-layer. Among them, motors with odd-layer pin hairpin coils offer more combinations of series turns per phase due to their connection method, enabling the motor to meet the performance requirements of low-speed torque and high-speed power, and thus match specific motor power requirements, attracting increasing attention.

[0003] However, in motors with odd-numbered pin hairpin coils, there are situations where the innermost or outermost layer of the stator winding welding end needs to be welded on the same layer. The same-layer welding process not only requires the addition of a pre-separation device for the same-layer pin hairpin coil to pre-separate the pin hairpin coil, but also makes the welding process complex, involves many steps, and is difficult to weld. Moreover, the reverse twisting of the pre-separated pin hairpin coil can easily cause the innermost or outermost pin hairpin coil to twist itself, thus occupying a large space and resulting in low space utilization. Summary of the Invention

[0004] The main objective of this invention is to propose a stator assembly and motor that aims to solve the problems of high difficulty in welding stator windings on the same layer and low space utilization in motors with odd-numbered hairpin coils.

[0005] To achieve the above objectives, the present invention provides a stator assembly, the stator assembly comprising:

[0006] A stator core having a plurality of stator slots formed on the radial inner surface of the stator core and spaced apart by a predetermined slot pitch along the circumferential direction of the stator core.

[0007] The stator winding includes multiple phase windings mounted on the stator core, and M layers are formed on each stator slot, where M is an odd number greater than or equal to 3;

[0008] Each phase winding includes multiple coil units connected in series. Each coil unit includes a first U-shaped hairpin winding, an I-shaped hairpin winding, and a second U-shaped hairpin winding. The first U-shaped hairpin winding is located in the innermost layer of the stator slot, the I-shaped hairpin winding is located in the middle layer of the stator slot, and the second U-shaped hairpin winding is located in the outermost layer of the stator slot.

[0009] The opening directions of the first U-shaped hairpin winding and the second U-shaped hairpin winding are opposite.

[0010] Optionally, when M equals 3, the type I hairpin winding includes a first type I hairpin sub-winding, the two ends of which are respectively connected to one end of the first U-shaped hairpin winding and one end of the second U-shaped hairpin winding.

[0011] Optionally, when M equals 5, the type I hairpin winding includes a first type I hairpin sub-winding and a second type I hairpin winding, wherein the first type I hairpin winding and the second type I hairpin winding are arranged in a mirror symmetrical structure.

[0012] The first type I hairpin winding is set in the middle layer with an odd number of layers, and the second type I hairpin winding is set in the middle layer with an even number of layers;

[0013] The first type I hairpin winding is used to connect the end-to-end second type I hairpin windings of different intermediate layers;

[0014] The second type I hairpin winding is used to connect the first type I hairpin winding and the first U-type hairpin winding end to end, and to connect the first type I hairpin winding and the second U-type hairpin winding end to end.

[0015] Optionally, when M is greater than 5, the type I hairpin winding includes a first type I hairpin sub-winding and a second type I hairpin winding, wherein the first type I hairpin winding and the second type I hairpin winding are arranged in a mirror symmetrical structure.

[0016] The first type I hairpin winding is set in the middle layer with an odd number of layers, and the second type I hairpin winding is set in the middle layer with an even number of layers;

[0017] The first type I hairpin winding is used to connect the second type I hairpin winding of the first adjacent layer and the second type I hairpin winding of the second adjacent layer end to end;

[0018] The second type I hairpin winding is used to connect the first type I hairpin winding of the adjacent layer and the first U-shaped hairpin winding of the adjacent layer end to end, and to connect the first type I hairpin winding of the adjacent layer and the second U-shaped hairpin winding of the fourth adjacent layer end to end.

[0019] Optionally, both the first U-shaped hairpin winding and the second U-shaped hairpin winding include a connecting section, two first straight sections, two first bent sections, and two first welded sections. The connecting section is connected between the two first straight sections. One end of each of the two first bent sections is connected to the end of each of the two first straight sections away from the connecting section, and the two first bent sections are arranged in parallel. The two first welded sections are connected to the other end of each of the first bent sections, and the first welded sections are arranged in parallel with the first straight sections.

[0020] The two first straight sections are respectively inserted into the two stator slots, and the connecting section and the first bent section respectively protrude from the two end faces of the stator core;

[0021] The distance between the first welding segment and the end face of the stator core is not less than the distance between the vertex of the connecting segment and the end face of the stator core.

[0022] Optionally, the type I hairpin winding includes a first type I hairpin sub-winding and / or a second type I hairpin winding. Both the first type I hairpin winding and the second type I hairpin winding include a second straight section, two second bent sections, and two second welded sections. One end of each of the two second bent sections is connected to both ends of the second straight section, and the two second bent sections are arranged in parallel. The two second welded sections are connected to the other end of the first bent section, and the second welded sections are arranged in parallel with the second straight section.

[0023] The second straight section passes through the stator slot, and the two second bent sections protrude from the two end faces of the stator core, respectively;

[0024] The distance between the second welded segment and the end face of the stator core is not less than the distance between the vertex of the first U-shaped hairpin winding and / or the distance between the vertex of the second U-shaped hairpin winding and the end face of the stator core; and / or, the distance between the second welded segment and the end face of the stator core is not less than the distance between the vertex of the second U-shaped hairpin winding and the end face of the stator core.

[0025] Optionally, each of the phase windings includes a lead wire and a neutral wire, which are disposed in adjacent layers of the stator slot.

[0026] Optionally, the number of stator slots is N, where N is a multiple of 3 and is an even number.

[0027] Optionally, the pitch of the first U-shaped hairpin winding is a short pitch, a full pitch, or a long pitch; the pitch of the second U-shaped hairpin winding is a short pitch, a full pitch, or a long pitch.

[0028] On the other hand, the present invention also proposes an electric motor, the electric motor including a rotor and a stator assembly as described above, the rotor being disposed within the stator assembly and capable of rotating relative to the stator assembly.

[0029] In the stator assembly of this invention, each of the multiple stator slots has an innermost layer and an outermost layer. The innermost layer of the stator slot is located near the slot opening, and the outermost layer is located near the bottom wall of the stator slot. An intermediate layer exists between the innermost and outermost layers within the multiple stator slots. In the innermost, intermediate, and outermost layers of the stator slots, a first U-shaped hairpin winding is provided in the innermost layer, an I-shaped hairpin winding is provided in the intermediate layer, and a second U-shaped hairpin winding is provided in the outermost layer. The opening orientation of the first U-shaped hairpin winding is opposite to that of the second U-shaped hairpin winding. That is, the first and second U-shaped hairpin windings are inserted into their respective stator slots from both ends of the stator core. The first U-shaped hairpin winding and the adjacent intermediate layer... The I-type hairpin winding is welded, and the second U-type hairpin winding is welded to the I-type hairpin winding in the adjacent intermediate layer, so that multiple first U-type hairpin windings or multiple second U-type hairpin coils do not need to be welded in the same layer. In this invention, by setting the first U-type hairpin winding and the second U-type hairpin winding with their openings facing away from each other in the innermost and outermost layers of the stator slot, respectively, the first U-type hairpin winding and the second U-type hairpin winding only need to be welded to the I-type hairpin winding, avoiding the same-layer welding between the first U-type hairpin windings and between the second U-type hairpin windings, greatly simplifying the process steps, reducing the welding difficulty, effectively preventing the first U-type hairpin winding and the second U-type hairpin winding from self-twisting, reducing the space occupied, and improving the space utilization rate. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the assembly structure of the stator assembly and the rotor according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the assembly structure of a stator assembly according to an embodiment of the present invention;

[0033] Figure 3 This is an exploded structural diagram of a stator assembly according to an embodiment of the present invention;

[0034] Figure 4 This is a partial structural schematic diagram of a stator assembly according to an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of the structure of the first U-shaped hairpin winding in the stator assembly according to an embodiment of the present invention;

[0036] Figure 6 This is a schematic diagram of the assembly structure of the first U-shaped hairpin winding and the stator core according to an embodiment of the present invention;

[0037] Figure 7 This is a schematic diagram of the structure of the second U-shaped hairpin winding in the stator assembly according to an embodiment of the present invention;

[0038] Figure 8 This is a schematic diagram of the assembly structure of the second U-shaped hairpin winding and the stator core according to an embodiment of the present invention;

[0039] Figure 9 This is a schematic diagram of the structure of the first type I hairpin winding in the stator assembly according to an embodiment of the present invention;

[0040] Figure 10 This is a schematic diagram of the assembly structure of the first type I hairpin winding and the stator core according to an embodiment of the present invention;

[0041] Figure 11 This is a schematic diagram of the structure of the second type I hairpin winding in the stator assembly according to an embodiment of the present invention;

[0042] Figure 12 This is a schematic diagram of the assembly structure of the second type I hairpin winding and the stator core according to an embodiment of the present invention;

[0043] Figure 13 This is a schematic diagram of the circuit structure of the stator winding in a stator assembly according to an embodiment of the present invention;

[0044] Figure 14 This is a schematic diagram of the circuit structure of the stator winding in the stator assembly according to another embodiment of the present invention;

[0045] Figure 15 This is a schematic diagram of the connection method of the stator winding in a stator assembly according to an embodiment of the present invention;

[0046] Figure 16 This is a schematic diagram of the connection method of the stator winding in the stator assembly according to another embodiment of the present invention.

[0047] Explanation of icon numbers:

[0048] label name label name 100 stator assembly 223 First bend section 10 stator core 224 First welding section 11 stator slot 23 Type I hairpin winding 12 Insulating paper 23a Type I hairpin winding 20 stator winding 23b Type II hairpin winding 21 Phase winding 231 Second straight section 22a First U-shaped hairpin winding 232 Second bend section 22b Second U-shaped hairpin winding 233 Second welding section 221 Connecting segment 200 motor 222 First straight segment 201 rotor

[0049] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0050] The technical solutions in this embodiment will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this embodiment are only used to explain the relative positional relationship and movement of each component in a specific posture (as shown in the attached figure). If the specific posture changes, the directional indicator will also change accordingly.

[0052] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0053] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0054] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible to those skilled in the art. If a combination of technical solutions contradicts each other or cannot be implemented, such a combination should be considered non-existent and not within the scope of protection claimed by the present invention. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0055] In this invention, the descriptions of directions such as "up," "down," "front," "back," "left," and "right" are as follows: Figure 1 and Figure 2 The directions shown are for reference only and are used to interpret the location. Figure 1 and Figure 2 The relative positional relationship between the components in the shown posture is such that if the specific posture changes, the directional indication will also change accordingly.

[0056] The present invention proposes a stator assembly 100.

[0057] like Figures 1 to 14 As shown, the stator assembly 100 includes a stator core 10 and a stator winding 20. The stator core 10 has a plurality of stator slots 11 formed on the radially inner surface of the stator core 10 and spaced apart by a predetermined slot pitch along the circumferential direction of the stator core 10. The stator winding 20 includes a plurality of phase windings 21 mounted on the stator core 10, and M layers are formed on each stator slot 11, where M is an odd number greater than or equal to 3. Each phase winding 21 includes a phase winding. Multiple coil units are connected in series. Each coil unit includes a first U-shaped hairpin winding 22a, an I-shaped hairpin winding 23, and a second U-shaped hairpin winding 22b. The first U-shaped hairpin winding 22a is located in the innermost layer of the stator slot 11, the I-shaped hairpin winding 23 is located in the middle layer of the stator slot 11, and the second U-shaped hairpin winding 22b is located in the outermost layer of the stator slot 11. The opening directions of the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b are opposite.

[0058] Specifically, the stator core 10 is used to wind a first U-shaped hairpin winding 22a, an I-shaped hairpin winding 23, and a second U-shaped hairpin winding 22b. A through-hole is formed in the center of the stator core 10, and multiple stator slots 11 are formed on the wall of the through-hole. These slots are evenly distributed circumferentially along the wall of the through-hole. Each stator slot 11 is a long, narrow slot structure, meaning each slot extends axially along the stator core 10. Insulating paper 12 is laid on the wall of each stator slot 11. The insulating paper 12 is used to isolate the coil unit from the slot wall of the stator slot 11, thus maintaining insulation between the coil unit and the stator core 10. It should be noted that, as... Figures 1 to 4 As shown, M layers are formed in the stator slot 11 along its depth direction. Each layer can accommodate multiple first U-shaped hairpin windings 22a, multiple I-shaped hairpin windings 23, or multiple second U-shaped hairpin windings 22b. The M layers of the stator slot 11 are not physically isolated or distinguished from each other, that is, the M layers of the stator slot 11 are interconnected and do not have clear dividing lines. The reason for dividing the inner space of the stator slot 11 into M layers is to better explain the distribution of the first U-shaped hairpin windings 22a, I-shaped hairpin windings 23, and second U-shaped hairpin windings 22b in the stator slot 11.

[0059] In this embodiment, the stator winding 20 of the stator assembly 100 includes at least three-phase windings 21, and the three-phase windings 21 can be connected in a star configuration, such as... Figure 13 As shown, or a delta connection method can be used for connection, such as... Figure 14As shown. The stator winding 20 with a star connection has a larger equivalent number of turns, suitable for situations where the motor 200 has a high voltage load; the stator winding 20 with a delta connection has a smaller equivalent number of turns, suitable for situations where the motor 200 has a high current load. Furthermore, each phase winding 21 includes at least two parallel branch windings, and each branch winding includes multiple coil units connected in series. Each coil unit includes a first U-shaped hairpin winding 22a, an I-shaped hairpin winding 23, and a second U-shaped hairpin winding 22b, ensuring symmetrical inductance among the phase windings 21 and effectively preventing circulating currents between the phase windings 21.

[0060] In this embodiment, each of the multiple stator slots 11 has an innermost layer and an outermost layer. The innermost layer of the stator slot 11 is located near the slot opening, and the outermost layer is located near the bottom wall of the stator slot 11. An intermediate layer exists between the innermost and outermost layers within the multiple stator slots 11. In the innermost, intermediate, and outermost layers of the stator slot 11, a first U-shaped hairpin winding 22a is provided in the innermost layer, an I-shaped hairpin winding 23 is provided in the intermediate layer, and a second U-shaped hairpin winding 22b is provided in the outermost layer. The opening orientation of the first U-shaped hairpin winding 22a is opposite to that of the second U-shaped hairpin winding 22b. That is, the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b are inserted from both ends of the stator core 10 into the corresponding stator slots 11. The first U-shaped hairpin winding 22a and the adjacent I-shaped hairpin winding 23 in the intermediate layer... The first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b are welded together, and the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b are welded together in the adjacent intermediate layer. This eliminates the need for welding between multiple first U-shaped hairpin windings 22a or between multiple second U-shaped hairpin windings 22b in the same layer. In this embodiment, the first U-shaped hairpin windings 22a and the second U-shaped hairpin windings 22b with their openings facing away from each other are respectively located in the innermost and outermost layers of the stator slot 11. This allows the first U-shaped hairpin windings 22a and the second U-shaped hairpin windings 22b to be welded only to the I-shaped hairpin winding 23, avoiding welding between the first U-shaped hairpin windings 22a and between the second U-shaped hairpin windings 22b in the same layer. This greatly simplifies the process steps, reduces the welding difficulty, effectively prevents the first U-shaped hairpin windings 22a and the second U-shaped hairpin windings 22b from self-twisting, reduces the space occupied, and improves the space utilization rate.

[0061] In one embodiment, when M equals 3, the type I hairpin winding 23 includes a first type I hairpin sub-winding 23a, the two ends of which are respectively connected to one end of a first U-shaped hairpin winding 22a and one end of a second U-shaped hairpin winding 22b. Specifically, three layers are formed in the stator slot 11. The first U-shaped hairpin winding 22a is disposed in the first layer of the stator slot 11, the first I-shaped hairpin sub-winding 23a is disposed in the second layer of the stator slot 11, and the second U-shaped hairpin winding 22b is disposed in the third layer of the stator slot 11. The first end of the first I-shaped hairpin sub-winding 23a is connected to the open end of the first U-shaped hairpin winding 22a, and the second end of the first I-shaped hairpin winding 23a is connected to the open end of the second U-shaped hairpin winding 22b, so that the first U-shaped hairpin winding 22a in the first layer, the first I-shaped hairpin winding 23a in the second layer, and the second U-shaped hairpin winding 22b in the third layer are connected in series.

[0062] In another embodiment, when M equals 5, the type I hairpin winding 23 includes a first type I hairpin sub-winding 23a and a second type I hairpin winding 23b, with the first type I hairpin winding 23a and the second type I hairpin winding 23b arranged in a mirror symmetrical structure.

[0063] The first type I hairpin winding 23a is set in the middle layer with an odd number of layers, and the second type I hairpin winding 23b is set in the middle layer with an even number of layers.

[0064] The first type I hairpin winding 23a is used to connect the first and last ends of the second type I hairpin winding 23b with different intermediate layers;

[0065] The second type I hairpin winding 23b is used to connect the first type I hairpin winding 23a and the first U-shaped hairpin winding 22a end to end, and to connect the first type I hairpin winding 23a and the second U-shaped hairpin winding 22b end to end.

[0066] In another embodiment, when M is greater than 5, the type I hairpin winding 23 includes a first type I hairpin sub-winding 23a and a second type I hairpin winding 23b, and the first type I hairpin winding 23a and the second type I hairpin winding 23b are arranged in a mirror symmetrical structure.

[0067] The first type I hairpin winding 23a is set in the middle layer with an odd number of layers, and the second type I hairpin winding 23b is set in the middle layer with an even number of layers.

[0068] The first type I hairpin winding 23a is used to connect the second type I hairpin winding 23b of the first adjacent layer and the second type I hairpin winding 23b of the second adjacent layer end to end.

[0069] The second type I hairpin winding 23a is used to connect the first type I hairpin winding 23a of the adjacent layer and the first U-shaped hairpin winding of the adjacent layer end to end, connect the first type I hairpin winding 23a of the adjacent layer and the second U-shaped hairpin winding 22b of the adjacent layer end to end, and connect the first type I hairpin winding 23a of the third adjacent layer and the first type I hairpin winding 23a of the fourth adjacent layer end to end.

[0070] Specifically, there are multiple intermediate layers between the innermost and outermost layers of the stator slot 11. Among the multiple intermediate layers of the stator slot 11, the intermediate layers with an odd number of layers are provided with only the first type I hairpin winding 23a, and the intermediate layers with an even number of layers are provided with only the second type I hairpin winding 23b.

[0071] The first adjacent layer is the layer preceding the layer containing the first type I hairpin winding 23a, and the second adjacent layer is the layer following the layer containing the first type I hairpin winding 23a. The third adjacent layer is the layer preceding the layer containing the second type I hairpin winding 23b, and the fourth adjacent layer is the layer following the layer containing the second type I hairpin winding 23b. The layers preceding the layers containing the first type I hairpin winding 23a and the second type I hairpin winding 23b can be set according to actual needs. For example, the layer adjacent to the stator outer diameter of the layer containing the first type I hairpin winding 23a can be designated as the first adjacent layer, or the layer adjacent to the stator outer diameter of the layer containing the first type I hairpin winding 23a can be designated as the first adjacent layer. The naming method for the second, third, and fourth adjacent layers is similar to that of the first adjacent layer and will not be repeated.

[0072] like Figures 9 to 12As shown, the first type I hairpin winding 23a is located in the Xth layer, where X is an odd number and the Xth layer is an intermediate layer. Second type I hairpin windings 23b are provided in both the X-1th and X+1th layers. The first end of the first type I hairpin winding 23a is connected to the second type I hairpin winding 23b in the X-1th layer, and the second end of the first type I hairpin winding 23a is connected to the second type I hairpin winding 23b in the X+1th layer. Further, when M equals 5, X = 3. The first end of the second type I hairpin winding 23b in the second layer is connected to the first end of the first type I hairpin winding 23a in the third layer, and the second end of the second type I hairpin winding 23b in the second layer is connected to the first U-shaped hairpin winding 22a in the first layer. The first end of the second type I hairpin winding 23b in the fourth layer is connected to the second end of the first type I hairpin winding 23a in the third layer. Then, the second end of the second type I hairpin winding 23b in the fourth layer is connected to the second U-shaped hairpin winding 22b in the fifth layer; when M is greater than 5, the first end of the second type I hairpin winding 23b in the (X-1)th layer is connected to the first type I hairpin winding 23a in the Xth layer, and the second end of the second type I hairpin winding 23b in the (X-1)th layer is connected to the first type I hairpin winding 23a in the (X-2)th layer; that is, the two ends of the second type I hairpin winding 23b can be connected to two adjacent first type I hairpin windings 23a respectively; or, the two ends of the second type I hairpin winding 23b are connected to an adjacent first type I hairpin winding 23a and a first U-shaped hairpin winding 22a respectively; or, the two ends of the second type I hairpin winding 23b are connected to an adjacent first type I hairpin winding 23a and a second U-shaped hairpin winding 22b respectively.

[0073] In one embodiment, both the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b include a connecting section 221, two first straight sections 222, two first bent sections 223, and two first welded sections 224. The connecting section 221 is connected between the two first straight sections 222. One end of each of the two first bent sections 223 is connected to the end of each of the two first straight sections 222 away from the connecting section 221, and the two first bent sections 223 are arranged in parallel. The two first welded sections 224 are connected to the other end of each of the first bent sections 223, and the first welded sections 224 are arranged in parallel with the first straight sections 222. The two first straight sections 222 are respectively inserted into the two stator slots 11, and the connecting section 221 and the first bent sections 223 respectively protrude from the two end faces of the stator core 10. The distance between the first welded section 224 and the end face of the stator core 10 is not less than the distance between the vertex of the connecting section 221 and the end face of the stator core 10.

[0074] like Figures 5 to 8As shown, two first straight segments 222 are respectively connected to the two ends of the connecting segment 221. Each first straight segment 222 is connected to a first bent segment 223 at the end away from the connecting segment 221. Each first bent segment 223 is connected to a first welding segment 224 at the end away from the first straight segment 222. The first welding segment 224 and the first straight segment 222 are arranged parallel to each other. The first bent segment 223 and the first straight segment 222 are arranged at an angle, which is not equal to 0 degrees or 180 degrees. The two first straight segments 222 are respectively located in the innermost layer of the two stator slots 11 or the outermost layer of the two stator slots 11. The first bending segment 223 is bent to connect the first straight segment 222 and the first welding segment 224. The first welding segment 224 is the welding end of the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b. The first bending segment 223 and the first welding segment 224 protrude from one end face of the stator core 10 so that the first bending segment 223 can be bent to one side, so that the welding end of the first welding segment 224 and the welding end of the I-shaped hairpin winding 23 in the intermediate layer can be welded between different layers. This can eliminate the same-layer welding process, reduce the manufacturing cost of the motor 200, and improve the manufacturing efficiency of the motor 200. Meanwhile, the distance between the first welding section 224 and the end face of the stator core 10 is not less than the distance between the vertex of the connecting section 221 and the end face of the stator core 10. This can prevent the first U-shaped hairpin winding and the second U-shaped hairpin winding from shifting outward or avoiding each other, so that the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b only need to be welded to the I-shaped hairpin winding 23. This avoids same-layer welding between the first U-shaped hairpin winding 22a and between the second U-shaped hairpin winding 22b, greatly simplifies the process steps, reduces the welding difficulty, effectively prevents the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b from self-twisting, reduces the space occupied, and improves the space utilization rate.

[0075] In a preferred embodiment, the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b are centrally symmetrically arranged. The first welding section 224 of the first U-shaped hairpin winding 22a is welded to the adjacent I-shaped hairpin winding 23, and the first welding section 224 of the second U-shaped hairpin winding 22b is welded to the adjacent I-shaped hairpin winding 23. This ensures that there is no spatial radial and circumferential interference between the coil units of each phase of the stator winding 20, and the input and output lines of each phase are arranged compactly, reducing the resistance imbalance rate. Furthermore, each phase lead does not require the use of a busbar, and the neutral point of each phase of the stator winding 20 is radially located on the same layer. The neutral point busbar structure is simple and short in length. The neutral point busbar can be formed by bending flat copper bars, eliminating the need for separate mold making, reducing production costs, and improving processing efficiency.

[0076] In this embodiment, both the first type I hairpin winding 23a and the second type I hairpin winding 23b include a second straight section 231, two second bent sections 232, and two second welded sections 233. One end of each of the two second bent sections 232 is connected to both ends of the second straight section 231, and the two second bent sections 232 are arranged in parallel. The two second welded sections 233 are connected to the other end of the first bent section 223, and the second welded sections 233 are arranged in parallel with the second straight section 231. The second straight section 231 passes through the stator slot 11, and the two second bent sections 232 protrude from the two end faces of the stator core 10. The distance between the second welded section 233 and the end face of the stator core 10 is not less than the distance between the vertex of the first U-shaped hairpin winding and the end face of the stator core 10; and / or, the distance between the second welded section 233 and the end face of the stator core 10 is not less than the distance between the vertex of the second U-shaped hairpin winding and the end face of the stator core 10. Specifically, two second bent segments 232 are respectively connected to both ends of the second straight segment 231. The two second bent segments 232 are arranged in a centrally symmetrical structure, and each second bent segment 232 has a second welded segment 233 connected to the end away from the second straight segment 231. The second straight segment 231 passes through the stator slot 11, and the two second bent segments 232 and the two second welded segments 233 protrude from the two end faces of the stator core 10. The vertex of the first U-shaped hairpin winding and / or the vertex of the second U-shaped hairpin winding can be understood as the vertex of the aforementioned connecting segment 221.

[0077] like Figures 9 to 12 As shown, the second straight section 231 of the first type I hairpin winding 23a can be located in any stator slot 11 of the intermediate layer where the number of layers is odd, and the second welding section 233 of the first type I hairpin winding 23a is welded to the second welding section 233 of the second type I hairpin winding 23b. The second straight section 231 of the second type I hairpin winding 23b can be located in any stator slot 11 of the intermediate layer where the number of layers is even, and the second welding section 233 of the second type I hairpin winding 23b can be welded to the second welding section 233 of the first type I hairpin winding 23a, the first welding section 224 of the first U-shaped hairpin winding 22a, or the first welding section 224 of the second U-shaped hairpin winding 22b.

[0078] In this embodiment, the distance between the second welding segment 233 and one end of the stator core 10 is not less than the distance between the connecting segment 221 and one end of the stator core 10. For example... Figure 2As shown, the second welding segment 233 extends vertically from the second bending segment 232 in a direction away from the stator core 10. The connecting segment 221 is bent and protrudes from the end face of the stator core 10. The distance between the end of the second welding segment 233 away from the second bending segment 232 and the end face of the stator core 10 is greater than or equal to the distance between the connecting segment 221 and the end face of the stator core 10, so as to avoid the second welding segment 233, facilitate the welding of the second welding segment 233 with the adjacent second welding segment 233 or the first welding segment 224, reduce the welding difficulty, and improve the welding efficiency.

[0079] In one embodiment, each phase winding 21 includes a lead wire and a neutral wire, which are arranged in adjacent layers of the stator slot 11. Specifically, by arranging the lead wires and neutral wires of different branch windings within the same phase winding 21 adjacent to each other, that is, bending two adjacent first bending segments 223 or two second bending segments 232 in the same direction, the lead wires and neutral wires of different branch windings within the same phase winding 21 can be in the same layer in the radial direction of the motor 200, reducing the extension length and volume of the corresponding busbar. Furthermore, the neutral point busbar connecting the branch windings can be formed by simply bending flat copper busbars without the need for a separate mold, which helps to reduce the production cost of the motor 200 and improve the processing and manufacturing efficiency of the motor 200. In another embodiment, the lead wire and neutral wire of each phase winding 21 can also be set at one end of the stator core 10 away from the welding point of each hairpin winding, so that the busbar is set away from the welding end of the first U-shaped hairpin winding 22a, the second U-shaped hairpin winding 22b and the I-shaped hairpin winding 23, thereby facilitating the arrangement of the busbar at the side end of the stator core 10.

[0080] In a preferred embodiment, the first type I hairpin winding 23a and the second type I hairpin winding 23b are symmetrically arranged. The second welding section 233 of the first type I hairpin winding 23a and the second welding section 233 of the second type I hairpin winding 23b can serve as the lead wire and neutral wire of the branch winding, so that the distance between the second welding section 233 of the adjacent first type I hairpin winding 23a and the second welding section 233 of the second type I hairpin winding 23b is closer, thereby further shortening the length of the busbar and reducing the production cost of the motor 200. Furthermore, the pitch between the first type I hairpin winding 23a and the second type I hairpin winding 23b welded thereto is N / 2p, that is, a full-pitch hairpin coil is formed between the first type I hairpin winding 23a and the second type I hairpin winding 23b welded thereto; the pitch between the second type I hairpin winding 23b and the first type I hairpin winding 23a, the first U-shaped hairpin winding 22a or the second U-shaped hairpin winding 22b welded thereto is N / 2p, that is, a full-pitch hairpin coil is formed between the second type I hairpin winding 23b and the first type I hairpin winding 23a, the first U-shaped hairpin winding 22a or the second U-shaped hairpin winding 22b welded thereto, where 2p is the number of poles of the motor 200.

[0081] In this embodiment, the pitch of the first U-shaped hairpin winding 22a is a short pitch, a full pitch, or a long pitch; the pitch of the second U-shaped hairpin winding 22b is a short pitch, a full pitch, or a long pitch. Specifically, the pitch of the short-pitch first U-shaped hairpin winding 22a and the pitch of the short-pitch second U-shaped hairpin winding 22b are less than the pole pitch of the stator winding 20; the pitch of the full-pitch first U-shaped hairpin winding 22a and the pitch of the full-pitch second U-shaped hairpin winding 22b are equal to the pole pitch of the stator winding 20; and the pitch of the long-pitch first U-shaped hairpin winding 22a and the pitch of the long-pitch second U-shaped hairpin winding 22b are greater than the pole pitch of the stator winding 20. That is, the first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b can be divided into three types according to the pitch: short pitch, full pitch, or long pitch. The pitch of the first U-shaped hairpin winding 22a or the pitch of the second U-shaped hairpin winding 22b of each type is the number of stator slots 11 crossed by the two effective sides. The number of stator slots 11 crossed by the long pitch is greater than the number of stator slots 11 crossed by the full pitch, and the number of stator slots 11 crossed by the full pitch is greater than the number of stator slots 11 crossed by the short pitch.

[0082] Further, the pitch of the short-pitch first U-shaped hairpin winding 22a and the short-pitch second U-shaped hairpin winding 22b is N / 2p-1, the pitch of the full-pitch first U-shaped hairpin winding 22a and the full-pitch second U-shaped hairpin winding 22b is N / 2p, and the pitch of the long-pitch first U-shaped hairpin winding 22a and the long-pitch second U-shaped hairpin winding 22b is N / 2p+1; where 2p is the number of poles of the motor 200. In a preferred embodiment, N = 48, 2p = 8, the short pitch is 5, that is, there are 5 stator slots 11 between the two effective sides of the short pitch, the full pitch is 6, that is, there are 6 stator slots 11 between the two effective sides of the full pitch, and the long pitch is 7, that is, there are 7 stator slots 11 between the two effective sides of the long pitch. The first U-shaped hairpin winding 22a and the second U-shaped hairpin winding 22b simplify the process of inserting wires into the stator slot 11, facilitate the welding of coil windings in each branch winding, and improve processing efficiency. In a preferred embodiment, the first U-shaped hairpin winding 22a has a long pitch and the second U-shaped hairpin winding 22b has a short pitch, so that there is no spatial radial and circumferential interference between the hairpin windings in each phase winding 21, and the incoming and outgoing wires of each phase winding 21 are arranged compactly, further reducing the resistance imbalance rate.

[0083] In this embodiment, as Figures 2 to 12 As shown, insulating paper 12 is laid on the bottom wall and side wall of stator slot 11. The insulating paper 12 isolates the first U-shaped hairpin winding 22a, the second U-shaped hairpin winding 22b, the first I-shaped hairpin sub-winding 23a, and the second I-shaped hairpin winding 23b from the stator slot 11 wall, thereby improving the insulation between the stator winding 20 and the stator core 10. Furthermore, the two ends of the insulating paper 12 protrude from the two end faces of the stator core 10, further improving the insulation performance of the stator assembly 100.

[0084] In this embodiment, the stator assembly 100 has N stator slots 11, where N is a multiple of 3 and is an even number. The phase windings 21 can be connected in a star or delta configuration. Each phase winding 21 consists of two branch windings connected in parallel. Each set of branch windings consists of NM / 4m coil units distributed in each layer of the stator slot 11 connected in series, where m is the number of phases of the motor 200. In a preferred embodiment, m = 3, meaning each set of branch windings includes 28 coil units connected in series. By optimizing the connection of the jumpers between the parallel sub-windings, the stator assembly 100 of this embodiment reduces the types of hairpin windings, thus reducing the types of wire types and molds, and improving the manufacturing efficiency of the motor 200. Furthermore, the current in each parallel phase winding 21 is equal, avoiding circulating currents between the parallel phase windings 21, thereby significantly reducing additional AC copper losses at high frequencies, improving the efficiency of the motor 200 during high-speed operation, preventing local overheating of the windings, and extending the service life of the motor 200.

[0085] In one embodiment, such as Figure 15 As shown, N=48, meaning there are 48 stator slots on the wall of the through hole; M=7, meaning each stator slot is divided into 7 layers. The dashed arrows indicate the connection between the straight segments of the hairpin winding on one side of the stator core 10 axial direction, and the solid arrows indicate the connection between the straight segments of the hairpin winding on the other side of the stator core 10 axial direction. U1+ and U1- represent the two leads of one branch winding, and U2- and U2+ represent the two leads of the other branch winding. The two branch windings are connected in parallel, for example, U1- connects to U2-, and U1+ connects to U2+. The stator windings 20 within the stator assembly 100 are arranged as follows: the coil unit includes 8 second U-shaped hairpin windings and 40 I-shaped hairpin windings. One branch winding U1 has its lead U1+ located in the 7th layer of the stator slot, and its neutral line U1- located in the 6th layer of the stator slot. The branch winding U1 starts from the lead U1+ in the 7th layer of the stator slot. Two first straight segments of one of the second U-shaped hairpin windings are located in the 7th layer of the 1st stator slot and the 7th layer of the 44th stator slot, respectively. This second U-shaped hairpin winding is welded to a second I-shaped hairpin winding located in the 6th layer of the 2nd stator slot. This second I-shaped hairpin winding is welded to a first I-shaped hairpin winding located in the 5th layer of the 8th stator slot. This first I-shaped hairpin winding is welded to the first... The second type I hairpin winding located in the 4th layer of stator slot 4 is welded, and so on, until the second type I hairpin winding located in the 2nd layer is welded to the first U-shaped hairpin winding located in the 1st layer of stator slot 32. The two first straight segments of the first U-shaped hairpin winding are located in the 1st layer of stator slot 32 and stator slot 25, respectively. The first U-shaped hairpin winding is welded to the second type I hairpin winding located in the 2nd layer of stator slot 19, and the second type I hairpin winding is welded to the first type I hairpin winding located in the 3rd layer of stator slot 13, and so on, until the second type I hairpin winding located in the 6th layer of stator slot 7 is welded to the neutral line U1-, thus completing the series connection of 28 coil units. The connection method of the other branch winding U2 is similar to that of branch winding U1, and will not be described in detail here. Furthermore, the pitch of the first U-shaped hairpin winding in the first layer is a long pitch of N / 2p+1, and the pitch between the straight segments of the remaining hairpin windings welded together at the ends on the same side is N / 2p. The pitch of the second U-shaped hairpin winding in the seventh layer is a short pitch of N / 2p-1, and the pitch between the straight segments of the remaining hairpin windings welded together at the ends on the same side is N / 2p.

[0086] In another embodiment, such as Figure 16As shown, N=48, meaning 48 stator slots are formed on the wall of the through hole; M=7, meaning each stator slot is divided into 7 layers. The dashed arrows indicate the connection between the straight segments of the hairpin winding on one side of the stator core 10's axial direction, and the solid arrows indicate the connection between the straight segments of the hairpin winding on the other side of the stator core 10's axial direction. U1+ and U1- represent the two leads of one branch winding, and U2- and U2+ represent the two leads of another branch winding. The two branch windings are connected in parallel, for example, U1- connects to U2-, and U1+ connects to U2+. The stator windings 20 in the stator assembly 100 are arranged as follows: the lead U1+ of one branch winding U1 is located in the 7th layer of the stator slot, and the neutral lead U1- is located in the 6th layer of the stator slot; the lead U2+ of the other branch winding U2 is located in the 7th layer of the stator slot, and the neutral lead U2- is located in the 6th layer of the stator slot. The connection method of branch windings U1 and U2 is as follows Figure 16 As shown, details will not be repeated here. Furthermore, the pitch of the first U-shaped hairpin winding in the first layer is a short pitch of N / 2p-1, and the pitch between the straight segments of the remaining hairpin windings welded together at the ends on the same side is N / 2p. The pitch of the second U-shaped hairpin winding in the seventh layer is a long pitch of N / 2p+1, and the pitch between the straight segments of the remaining hairpin windings welded together at the ends on the same side is N / 2p.

[0087] In the stator assembly 100 of this embodiment, the stator winding 20 input and output lines can be on any side of the stator core 10, and can also be in any two adjacent layers. Specifically, the motor 200 input and output lines can be adjusted to either the end where the connecting section 221 of the first U-shaped hairpin winding 22a is located, or to the end where the connecting section 221 of the second U-shaped hairpin winding 22b is located. In a preferred embodiment, the motor 200 input and output lines are located at the connecting section 221 of the first U-shaped hairpin winding 22a. The motor 200 input and output lines can be adjusted to any other two adjacent layers within the 7th and 6th layers of one end; the motor 200 input and output lines can be adjusted to any other two adjacent layers within the 1st and 2nd layers of one end where the connecting section 221 of the second U-shaped hairpin winding 22b is located; the stator winding 20 can have one parallel branch, connecting the U1- lead and the U2+ lead to each other so that all coil units of each phase are connected in series to form one branch, or it can have two branches, such as... Figure 13 and Figure 14 As shown.

[0088] The present invention also proposes a motor 200, which includes a rotor 201 and a stator assembly 100 as described above. The rotor 201 passes through the through hole of the stator core 10 and can rotate relative to the stator core 10. Specifically, the rotor 201 is formed by stamping multiple silicon steel sheets, and a rotating shaft passes through the middle of the rotor 201. The rotating shaft can drive the rotor 201 to rotate relative to the stator assembly 100 within the stator core 10. Furthermore, the stator assembly 100 of the present invention is applicable to various rotor magnetic circuit structures such as permanent magnet rotors, asynchronous rotors, and electrically excited rotors, and has high versatility. The specific structure of the stator assembly 100 is as described in the above embodiments. Since the motor 200 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0089] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A stator assembly characterized by, The stator assembly comprises: a stator core having a plurality of stator slots formed on a radially inner surface of the stator core and spaced apart along a circumferential direction of the stator core by a predetermined slot pitch; a stator winding comprising a plurality of phase windings mounted on the stator core and forming M layers on each of the stator slots, M being an odd number greater than or equal to 3; each of the phase windings comprises a plurality of coil units connected in series, each of the coil units comprising a first U-shaped hairpin winding, an I-shaped hairpin winding and a second U-shaped hairpin winding; the first U-shaped hairpin winding is located at an innermost layer of the stator slot, the I-shaped hairpin winding is located at an intermediate layer of the stator slot, and the second U-shaped hairpin winding is located at an outermost layer of the stator slot, wherein the opening directions of the first U-shaped hairpin winding and the second U-shaped hairpin winding are opposite.

2. The stator assembly of claim 1, wherein, When the M is equal to 3, the I-shaped hairpin winding comprises a first I-shaped hairpin sub-winding, two ends of the first I-shaped hairpin sub-winding being connected to one end of the first U-shaped hairpin winding and one end of the second U-shaped hairpin winding respectively.

3. The stator assembly of claim 1, wherein, When the M is equal to 5, the I-shaped hairpin winding comprises a first I-shaped hairpin sub-winding and a second I-shaped hairpin sub-winding, the first I-shaped hairpin sub-winding and the second I-shaped hairpin sub-winding being arranged in a mirror-symmetrical structure; the first I-shaped hairpin sub-winding is arranged in an intermediate layer with an odd number of layers, and the second I-shaped hairpin sub-winding is arranged in an intermediate layer with an even number of layers; the first I-shaped hairpin sub-winding is used to connect the second I-shaped hairpin sub-winding of different intermediate layers in series; the second I-shaped hairpin sub-winding is used to connect the first I-shaped hairpin sub-winding and the first U-shaped hairpin winding in series, and the first I-shaped hairpin sub-winding and the second U-shaped hairpin winding in series.

4. The stator assembly of claim 1, wherein, When the M is greater than 5, the I-shaped hairpin winding comprises a first I-shaped hairpin sub-winding and a second I-shaped hairpin sub-winding, the first I-shaped hairpin sub-winding and the second I-shaped hairpin sub-winding being arranged in a mirror-symmetrical structure; the first I-shaped hairpin sub-winding is arranged in an intermediate layer with an odd number of layers, and the second I-shaped hairpin sub-winding is arranged in an intermediate layer with an even number of layers; the first I-shaped hairpin sub-winding is used to connect the second I-shaped hairpin sub-winding of a first adjacent layer and the second I-shaped hairpin sub-winding of a second adjacent layer in series; the second I-shaped hairpin sub-winding is used to connect the first I-shaped hairpin sub-winding of an adjacent layer and the first U-shaped hairpin winding of the adjacent layer in series, and the first I-shaped hairpin sub-winding and the second U-shaped hairpin winding of the adjacent layer in series.

5. The stator assembly of claim 1, wherein, the first U-shaped hairpin winding and the second U-shaped hairpin winding each comprise a connection section, two first straight sections, two first bending sections and two first welding sections, the connection section being connected between the two first straight sections, one end of the two first bending sections being connected to one end of the two first straight sections away from the connection section respectively, the two first bending sections being arranged in parallel, the other end of the two first bending sections being connected to the two first welding sections respectively, and the first welding sections being arranged in parallel with the first straight sections; Two of the first straight sections are arranged in two of the stator slots respectively, and the connecting section and the first bent section protrude from two end faces of the stator core respectively. The first welding section is arranged at a distance from the end face of the stator core, and the distance is not less than a distance from an apex of the connecting section to the end face of the stator core.

6. The stator assembly of claim 5, wherein, The I-shaped hairpin winding includes a first I-shaped hairpin sub-winding and / or a second I-shaped hairpin sub-winding, the first I-shaped hairpin sub-winding and the second I-shaped hairpin sub-winding each include a second straight section, two second bent sections and two second welding sections, one end of each of the two second bent sections is connected to two ends of the second straight section, and the two second bent sections are arranged in parallel, and the other end of each of the second bent sections is connected to the second welding section, and the second welding section is arranged in parallel with the second straight section. The second straight section is arranged in the stator slot, and the two second bent sections protrude from two end faces of the stator core respectively. The second welding section is arranged at a distance from the end face of the stator core, and the distance is not less than a distance from an apex of the first U-shaped hairpin winding to the end face of the stator core, and / or the distance is not less than a distance from an apex of the second U-shaped hairpin winding to the end face of the stator core.

7. The stator assembly of any one of claims 1-5, wherein, Each of the phase windings includes a lead wire and a neutral wire, and the lead wire and the neutral wire are arranged in adjacent layers of the stator slots.

8. The stator assembly of any one of claims 1-5, wherein, The number of the stator slots is N, N is a multiple of 3, and N is an even number.

9. The stator assembly of any one of claims 1-5, wherein, The pitch of the first U-shaped hairpin winding is a short pitch, an integral pitch or a long pitch, and the pitch of the second U-shaped hairpin winding is a short pitch, an integral pitch or a long pitch.

10. An electric machine characterized by The motor includes a rotor and the stator assembly according to any one of claims 1-9, the rotor is arranged in the stator assembly and can rotate relative to the stator assembly.

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