Motor stator and motor

Abstract

The utility model provides a motor stator and a motor. According to the motor stator, the cooling fluid flowing in from the inlet of the ring assembly can enter the first cavity, and then the cooling fluid flows into the hollow flow path through the first opening of each hairpin unit, so that the whole winding can be directly cooled. The cooled cooling fluid enters the second chamber from the second opening of each card issuing unit and then is discharged from the discharge port communicated with the second chamber. Therefore, in the motor stator, the whole winding can be directly cooled by using the cooling fluid, a conduction path for transferring heat from the winding to the cooling fluid is greatly reduced, and the cooling effect on the whole winding is effectively improved. Moreover, as the cooling fluid flows in the hairpin units of the winding, relative fixation between the winding and the iron core through adhesive glue outside the winding and the like is not affected, and the problems of possible abrasion and NVH performance degradation of the winding are avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric machines, and in particular to an electric machine stator with an oil cooling structure and an electric machine comprising the same. BACKGROUND

[0002] Nowadays, electric machines are often used as a power source of output torque in pure electric vehicles or hybrid electric vehicles, and the cooling of the electric machine (especially the cooling of the electric machine stator) is very important for the performance of the electric machine. Since the cooling oil as a cooling fluid can directly contact the heat generating parts of the electric machine stator, the scheme of cooling the electric machine stator by using the cooling oil is superior to the scheme of cooling the electric machine stator by using water. The following patent documents disclose the scheme of cooling in the electric machine by using the cooling oil.

[0003] In the Chinese utility model patent with the publication number CN 212649253 U and the name "Electric machine oil cooling device, electric machine assembly and vehicle", a cooling method is realized in which the cooling oil is directly sprayed onto the first winding end portion and the second winding end portion to take away heat. In this scheme, although the two side end portions of the winding can be cooled, the conduction path of the heat generated by the main heat generating part of the winding of the electric machine stator (the part located in the wire slot of the iron core) to the cooling oil is very long, resulting in insufficient cooling capacity for the main heat generating part of the winding.

[0004] In the Chinese invention patent application with the publication number CN 109617319 A and the name "Flat wire electric machine in-slot oil cooling structure", a cooling method is realized in which the cooling oil in the in-slot cooling oil passage is used to directly cool the stator winding to take away heat. In this scheme, although the main heat generating part of the winding of the electric machine stator can be directly cooled, this scheme will result in that the winding cannot be fixed relative to the iron core, so that the electromagnetic wire constituting the winding can be abraded and result in the degradation of NVH performance. SUMMARY

[0005] The present application is made in view of the above-mentioned state of the art. One object of the present application is to provide an electric machine stator which can effectively cool each part of the winding while avoiding the abrasion of the winding and the degradation of NVH performance. Another object of the present application is to provide an electric machine comprising the above-mentioned electric machine stator.

[0006] In order to achieve the above-mentioned objects, the present application can adopt the following technical scheme.

[0007] The present application provides an electric machine stator comprising:

[0008] an iron core having a plurality of wire slots distributed at intervals in the circumferential direction of the electric machine stator;

[0009] a winding including a plurality of hairpin units inserted into the wire slot, twisted side end portions of different hairpin units being connected to make the winding form a predetermined electric circuit, each of the hairpin units being formed with a hollow flow path, and the hollow flow path being formed with a first opening and a second opening at both twisted side end portions of the hairpin unit, respectively; and

[0010] a ring assembly formed with an inlet port and an outlet port, and formed with a first chamber and a second chamber partitioned from each other, the inlet port communicating the first chamber with the outside of the ring assembly, the outlet port communicating the second chamber with the outside of the ring assembly, the twisted side end portion of each of the hairpin units being inserted into the ring assembly so that the first opening of each of the hairpin units communicates with the first chamber, thereby enabling the cooling fluid to be fed into the hairpin unit from the first opening via the inlet port and the first chamber; the second opening communicates with the second chamber, thereby enabling the cooling fluid in the hairpin unit to be discharged from the second opening via the second chamber and the outlet port.

[0011] In an alternative, the ring assembly has a first side wall, a second side wall, a first peripheral wall, a second peripheral wall and a partition wall fixed to each other,

[0012] the first side wall and the second side wall extend along the circumferential direction and oppose each other in the axial direction of the motor stator, the first peripheral wall and the second peripheral wall extend along the circumferential direction and oppose each other in the radial direction of the motor stator, and an internal space enclosed by the first side wall, the second side wall, the first peripheral wall and the second peripheral wall is partitioned into the first chamber and the second chamber by the partition wall.

[0013] In another alternative, the ring assembly includes a partition ring and an end cover assembled and fixed to each other,

[0014] the partition ring includes the first side wall, the first peripheral wall, the second peripheral wall and the partition wall formed as one body, the end cover includes the second side wall, and the first peripheral wall, the second peripheral wall and the partition wall stand from the first side wall toward the second side wall and abut against the second side wall.

[0015] In another alternative, the first side wall is formed with a through hole through which the twisted side end portion of the hairpin unit is sealingly inserted, and the twisted side end portions of a pair of the hairpin units connected to each other are inserted through one corresponding through hole.

[0016] In another alternative, the through hole includes a first end portion, an intermediate portion, and a second end portion which communicate with each other, the intermediate portion is located between the first end portion and the second end portion in the axial direction, at least one peripheral wall of the first end portion is formed with a chamfer, and a glue groove is formed between the peripheral wall of the second end portion and the torsion side end portion.

[0017] In another alternative, the peripheral wall of the second end portion and the torsion side end portion are connected together by a connecting portion formed by applying adhesive glue in the glue groove, and the connecting portion seals between the peripheral wall of the second end portion and the torsion side end portion.

[0018] In another alternative, a surface of the second side wall facing the first side wall is formed with a first mounting groove, a second mounting groove, and a third mounting groove,

[0019] the first mounting groove is the same as an extension trajectory of the first peripheral wall, and the first peripheral wall is inserted and mounted in the first mounting groove,

[0020] the second mounting groove is the same as an extension trajectory of the second peripheral wall, and the second peripheral wall is inserted and mounted in the second mounting groove, and

[0021] the third mounting groove is the same as an extension trajectory of the partition wall, and the partition wall is inserted and mounted in the third mounting groove.

[0022] In another alternative, a surface of the second side wall facing away from the first side wall is formed with a protruding welding guide portion, an extension trajectory of the welding guide portion is the same as extension trajectories of the first mounting groove, the second mounting groove, and the third mounting groove, and welding along the welding guide portion fixes the partition ring and the end cover together.

[0023] In another alternative, the hairpin unit includes a first insertion portion, a second insertion portion, a crown side end portion, a first torsion side end portion, and a second torsion side end portion which are fixed together,

[0024] the first insertion portion and the second insertion portion each extend linearly along the axial direction of the motor stator, the first insertion portion and the second insertion portion of the same hairpin unit are located in different wire grooves,

[0025] one end portion of the first insertion portion and one end portion of the second insertion portion are connected via the crown side end portion, the other end portion of the first insertion portion is connected to the first torsion side end portion, and the other end portion of the second insertion portion is connected to the second torsion side end portion.

[0026] The application also provides an electric machine comprising the electric machine stator.

[0027] By adopting the above technical solution, the application provides an electric machine stator and an electric machine comprising the electric machine stator. In the electric machine stator of the application, the electric machine stator comprises a core, a winding and a ring assembly assembled together. The core comprises a plurality of wire slots distributed at intervals in the circumferential direction of the electric machine stator. The winding comprises a plurality of hairpin units, the plurality of hairpin units are inserted into the wire slots, and the twisted side end portions of different hairpin units are connected to form a predetermined electric circuit. In addition, each hairpin unit is formed with a hollow flow path, and the hollow flow path has a first opening and a second opening at the two twisted side end portions of the hairpin unit, respectively. The ring assembly is formed with an inlet and an outlet, and is formed with a first chamber and a second chamber separated from each other, the inlet communicates the first chamber with the outside of the ring assembly, the outlet communicates the second chamber with the outside of the ring assembly, and the twisted side end portion of each hairpin unit is inserted into the ring assembly so that the first opening of each hairpin unit communicates with the first chamber, thereby enabling the cooling fluid to be introduced into the hairpin unit from the first opening via the inlet and the first chamber; the second opening communicates with the second chamber, so that the cooling fluid in the hairpin unit can be discharged from the second opening via the second chamber and the outlet.

[0028] In this way, the cooling fluid such as cooling oil flowing from the inlet of the ring assembly can enter the first chamber, and then the cooling fluid flows into the hollow flow path of the hairpin unit through the first opening of each hairpin unit to cool the hairpin unit, thereby enabling direct cooling of the entire winding. The cooled cooling fluid will enter the second chamber from the second opening of each hairpin unit and then be discharged via the outlet communicating with the second chamber. Therefore, in the electric machine stator according to the application, not only can the entire winding be directly cooled by the cooling fluid, but also the conduction path of heat transfer from the winding to the cooling fluid is greatly reduced, and the cooling effect of the entire winding is effectively improved. Moreover, since the cooling fluid flows inside the hairpin unit of the winding, it does not affect the relative fixation between the winding and the core through the adhesive or the like outside the winding, thereby avoiding the problems of wear and tear and NVH performance degradation that may occur in the winding. In addition, the cooling fluid enters the hairpin unit from the first opening of the hairpin unit through the inlet and the first chamber, and the cooling fluid flows out of the hairpin unit from the second opening of the hairpin unit through the second chamber and the outlet, rather than the cooling fluid flowing out of the hairpin unit to the electric machine cavity from other openings or holes of the hairpin unit other than the above first opening and second opening. The entry of the cooling fluid into the electric machine cavity can be reduced or avoided, and the cooling fluid will not be stirred by the electric machine rotor, thereby avoiding the generation of stirring noise, and also avoiding the problems of cooling fluid loss, kinetic energy loss and the like caused by the stirring of the cooling fluid by the electric machine rotor. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1A is a perspective schematic view showing a motor stator according to an embodiment of the present application.

[0030] Figure 1B is a perspective schematic view showing a motor stator according to an embodiment of the present application. Figure 1A is a perspective schematic view showing a motor stator in

[0031] Figure 1C is a perspective schematic view showing a motor stator according to an embodiment of the present application. Figure 1A is another perspective schematic view showing a motor stator in

[0032] Figure 1D is a perspective schematic view showing a motor stator according to an embodiment of the present application. Figure 1C is a perspective schematic view showing a partial configuration of

[0033] Figure 1E is a front schematic view showing a partial configuration of Figure 1C

[0034] Figure 1F is a partial sectional schematic view showing a motor stator in Figure 1A

[0035] Figure 2A is a perspective schematic view showing a hairpin unit of a winding of a motor stator in Figure 1A

[0036] Figure 2B is a perspective schematic view showing a partial configuration of a first twisted side end of a hairpin unit in Figure 2A

[0037] Figure 3A is a perspective schematic view showing a partition ring of a ring assembly of a motor stator in Figure 1A

[0038] Figure 3B is another perspective schematic view showing a partition ring in Figure 3A

[0039] Figure 3C is a schematic view showing a partial configuration of a partition ring in Figure 3A

[0040] Figure 3D is a schematic view showing a partial configuration of a partition ring in Figure 3A

[0041] Figure 4A is a perspective schematic view showing an end cover of a ring assembly of a motor stator in Figure 1A ​​​​​​​​​

[0042] Figure 4B is another perspective view showing Figure 4A the end cover.

[0043] Reference Signs List

[0044] 1 core; 1c winding slot; 11 yoke portion; 12 tooth;

[0045] 2 winding; 2a hairpin unit; 21 first insertion portion; 22 second insertion portion; 23 crown side end portion; 24 first torsion side end portion; 24o first opening; 25 second torsion side end portion; 25o second opening;

[0046] 3 ring assembly; 3c1 first chamber; 3c2 second chamber;

[0047] 31 partition ring; 311 first side wall; 311h through hole; 312 first peripheral wall; 313 second peripheral wall; 314 partition wall; 315 connecting portion;

[0048] 32 end cover; 32o1 inlet; 32o2 outlet; 32c1 first mounting groove; 32c2 second mounting groove; 32c3 third mounting groove; 321 second side wall; 322 welding guide portion;

[0049] A axial direction; C circumferential direction. DETAILED DESCRIPTION

[0050] The exemplary embodiments of the present application will be described hereinafter with reference to the accompanying drawings. It is to be understood that the specific description is only for the purpose of teaching one skilled in the art how to implement the present application, and is not intended to limit the scope of the present application.

[0051] In the present application, unless otherwise specified, "axial direction", "radial direction" and "circumferential direction" respectively refer to the axial direction, the radial direction and the circumferential direction of the motor stator.

[0052] The specific structure of the motor stator according to an embodiment of the present application will be described below with reference to the accompanying drawings.

[0053] In the present embodiment, as shown in Figures 1A-1C , the motor stator according to an embodiment of the present application includes a core 1, a winding 2 and a ring assembly 3 assembled together.

[0054] In the present embodiment, the core 1 can be composed of a plurality of silicon steel sheets fixed together in the axial direction A, each of which can be formed by stamping. As shown in Figures 1A-1CAs shown, the iron core 1 as a whole has a cylindrical structure, and the iron core 1 includes a magnetic yoke portion 11 and a plurality of teeth 12 fixed to each other. Specifically, the magnetic yoke portion 11 can be formed in an annular shape continuously extending along the circumferential direction C over the entire circumference, and the plurality of teeth 12 extend from the magnetic yoke portion 11 toward the radially inner side and are uniformly distributed at intervals in the circumferential direction C. A wire slot 1c for mounting a following described hairpin unit 2a of the winding 2 is formed between every two adjacent teeth 12, each wire slot 1c extends along the axial direction A and penetrates through the iron core 1, and each wire slot 1c is open toward the radially inner side and has a radial opening.

[0055] In the present embodiment, as shown in Figures 1A-1C , the winding 2 is fixedly mounted to the iron core 1. Specifically, the winding 2 is a hairpin winding that is inserted into the wire slot 1c of the iron core 1 through the hairpin unit 2a and is torsionally formed, and then is electrically connected, for example, by welding. The hairpin unit 2a is composed of a flat wire having a rectangular (including a square) shape in cross section, which can include, for example, a conductor made of copper and an insulating layer covering the outer side of the conductor.

[0056] As shown in Figure 2A and Figure 2B , each hairpin unit 2a includes a first insertion portion 21, a second insertion portion 22, a crown side end portion 23, a first torsion side end portion 24, and a second torsion side end portion 25 fixed to each other. The first insertion portion 21 and the second insertion portion 22 each extend linearly along the axial direction A, and the first insertion portion 21 and the second insertion portion 22 of the same hairpin unit 2a are located in different wire slots 1c and in different layers in the wire slots 1c. The crown side end portion 23 has a bent shape, one end portion of the first insertion portion 21 and one end portion of the second insertion portion 22 are connected to the crown side end portion 23, whereby the plurality of crown side end portions 23 constitute a crown-like structure of the axial end portion of the winding 2 after the winding 2 is mounted in place, and each crown layer constituted by each crown side end portion 23 corresponds to two layers of the insertion portions 21, 22 in the wire slot 1c. The first torsion side end portion 24 is connected to the other end portion of the first insertion portion 21 for connection and electrical connection, for example, by welding, to other hairpin units 2a; and the second torsion side end portion 25 is connected to the other end portion of the second insertion portion 22 for connection and electrical connection, for example, by welding, to other hairpin units 2a. By connecting the torsion side end portions 24, 25 of different hairpin units 2a, for example, by welding, the winding 2 can form a predetermined electrical circuit.

[0057] As shown in Figure 2A and Figure 2BAs shown, each hairpin unit 2a is formed with a hollow flow path configured to extend along the length of the entire hairpin unit 2a to pervade the entire hairpin unit 2a, the hollow flow path is formed with a first opening 24o at the end face of the first twisted side end 24 and a second opening 25o at the end face of the second twisted side end 25, so that a cooling fluid such as cooling oil flowing into the hollow flow path via one of the first opening 24o and the second opening 25o can flow out via the other. It can be understood that each hairpin unit 2a is not formed with any other opening or aperture in communication with the hollow flow path in addition to the first opening 24o and the second opening 25o described above.

[0058] In the present embodiment, as shown, Figures 1A-1F The ring assembly 3 is integrally formed in a circular ring shape and assembled together coaxially with the core 1. The ring assembly 3 has a first side wall (may also be referred to as a first axial end wall) 311, a second side wall (may also be referred to as a second axial end wall) 321, a first peripheral wall 312, a second peripheral wall 313 and a partition wall 314 fixed to each other, the first side wall 311 and the second side wall 321 continuously extend along the whole circumference C and oppositely face each other in the axial direction A, the first peripheral wall 312 and the second peripheral wall 313 continuously extend along the whole circumference C and oppositely face each other in the radial direction, an internal space enclosed by the first side wall 311, the second side wall 321, the first peripheral wall 312 and the second peripheral wall 313 is partitioned by the partition wall 314 into a first chamber 3c1 and a second chamber 3c2 which do not directly communicate with each other.

[0059] As shown, Figures 1A-1F The ring assembly 3 includes a partition ring 31 and an end cover 32 manufactured separately and fixedly assembled together. In the present embodiment, the partition ring 31 includes the first side wall 311, the first peripheral wall 312, the second peripheral wall 313 and the partition wall 314 formed integrally; while the end cover 32 includes the second side wall 321. As shown, Figure 3A and Figure 3B The first peripheral wall 312 stands up from the outer periphery of the first side wall 311 toward the second side wall 321, and the second peripheral wall 313 stands up from the inner periphery of the first side wall 311 toward the second side wall 321. The partition wall 314 is located between the first peripheral wall 312 and the second peripheral wall 313 and is formed in a shape of extending in a serpentine manner along the whole circumference C as a whole, the partition wall 314 stands up from the first side wall 311 toward the second side wall 321. The first peripheral wall 312, the second peripheral wall 313 and the partition wall 314 all abut against and fixedly connected (i.e. abut) with the second side wall 321. As shown, Figure 4A and Figure 4BAs shown, the surface of the second sidewall 321 facing the first sidewall 311 has a first mounting groove 32c1, a second mounting groove 32c2, and a third mounting groove 32c3. The first mounting groove 32c1 has the same extension trajectory as the first peripheral wall 312 (here, the trajectory extending along the circumferential direction C and the radial direction are the same), and the first peripheral wall 312 is inserted into the first mounting groove 32c1. The second mounting groove 32c2 has the same extension trajectory as the second peripheral wall 313, and the second peripheral wall 313 is inserted into the second mounting groove 32c2. The third mounting groove 32c3 has the same extension trajectory as the partition wall 314, and the partition wall 314 is inserted into the third mounting groove 32c3. Furthermore, a protruding welding guide 322 is formed on the surface of the second sidewall 321 facing away from the first sidewall 311. The welding guide 322 follows the same extension trajectory as the first mounting groove 32c1, the second mounting groove 32c2, and the third mounting groove 32c3 (that is, the welding guide 322 follows the same extension trajectory as the first peripheral wall 312, the second peripheral wall 313, and the partition wall 314). Welding (e.g., laser welding) is then performed along the welding guide 322 to fix the first peripheral wall 312, the second peripheral wall 313, and the partition wall 314 of the partition ring 31 to the end cap 32. With the partition ring 31 fixed to the end cap 32, as described above, the partition wall 314 divides the internal space of the ring assembly 3 into a first chamber 3c1 and a second chamber 3c2 that are not directly connected. Figures 1B-1F As shown, the first chamber 3c1 includes multiple interconnected sector regions, and the second chamber 3c2 also includes multiple interconnected sector regions. The sector regions of the first chamber 3c1 and the second chamber 3c2 are arranged alternately in the circumferential direction C.

[0060] like Figures 3A-3D As shown, the first sidewall 311 has through holes 311h through which the torsional ends 24 and 25 of the card-issuing unit 2a are inserted. These through holes 311h all extend through the first sidewall 311 along the axial direction A. Furthermore, multiple through holes 311h are arranged in an array in the fan-shaped regions of the first chamber 3c1 and the second chamber 3c2. The torsional ends 24 and 25 of the paired card-issuing units 2a are inserted through a corresponding through hole 311h. Further, as... Figure 1CAs shown, one of the first twisted side end 24 and the second twisted side end 25 of each hairpin unit 2a is inserted through the through hole 311h located at the first chamber 3c1, and the other one is inserted through the through hole 311h located at the second chamber 3c2, so that after being installed in place, the first opening 24o of each hairpin unit 2a communicates with the first chamber 3c1 and the second opening 25o communicates with the second chamber 3c2. In addition, in order to facilitate the insertion of the twisted side end 24, 25 of the hairpin unit 2a through the through hole 311h and ensure the sealing between the twisted side end 24, 25 of the hairpin unit 2a and the first side wall 311, the through hole 311h is configured to include a first end, an intermediate part and a second end which communicate with each other. In the axial direction A, the intermediate part is located between the first end and the second end, and the size of the intermediate part can match the size of the twisted ends 24, 25 of the pair of hairpin units 2a connected to each other. The first end can be away from the end cover 32 than the intermediate part, and at least one peripheral wall of the first end is formed with a chamfer, so that the peripheral wall of the first end functions as a guide for guiding the insertion of the twisted side end of the hairpin unit 2a into the through hole 311h. The second end can be closer to the end cover 32 than the intermediate part, and the peripheral wall of the second end forms a glue groove with the twisted side end 24, 25. In this way, the size of the second end can be slightly larger than the size of the twisted side ends 24, 25 of the pair of hairpin units 2a connected to each other inserted into the through hole 311h, so that between the peripheral wall of the second end of the through hole 311h and the twisted side end 24, 25, the connection part 315 formed by the curing of the added adhesive makes them connected together, and in turn the connection part 315 realizes the sealing between the peripheral wall of the second end and the twisted side end 24, 25. In this way, after the twisted side ends 24, 25 of the hairpin units 2a of the winding 2 are all inserted through the through hole 311h, a flow path is formed from the first chamber 3c1 of the ring assembly 3, through the first opening 24o of each hairpin unit 2a to the hollow flow path, and then through the second opening 25o back to the second chamber 3c2 of the ring assembly 3.

[0061] As shown in Figure 4A and Figure 4B The end cover 32 is also formed with an inlet port 32o1 for the cooling fluid to enter the first chamber 3c1 and an outlet port 32o2 for the cooling fluid to be discharged from the second chamber 3c2. The inlet port 32o1 and the outlet port 32o2 are arranged at an interval of 180 degrees in the circumferential direction, the inlet port 32o1 communicates the first chamber 3c1 with the outside of the ring assembly 3, and the outlet port 32o2 communicates the second chamber 3c2 with the outside of the ring assembly 3.

[0062] In this way, under the pumping action of the pumping mechanism, for example, the cooling fluid can enter the first chamber 3c1 from the inlet port 32o1 of the ring assembly 3, and then the cooling fluid flows into the hollow flow path of each hairpin unit 2a through the first opening 24o of the hairpin unit 2a for cooling, thereby enabling direct cooling of the entire winding 2. The cooled cooling fluid will enter the second chamber 3c2 from the second opening 25o of each hairpin unit 2a, and then be discharged through the discharge port 32o2 in communication with the second chamber 3c2. Therefore, in the motor stator according to the present application, not only can the entire winding 2 be directly cooled by the cooling fluid, but the conduction path of the heat from the winding 2 to the cooling fluid is greatly reduced, effectively improving the cooling effect of the entire winding 2. Moreover, since the cooling fluid flows inside the hairpin unit 2a of the winding 2, it does not affect the relative fixation of the winding 2 to the iron core 1 through the adhesive or the like outside the winding 2, thereby avoiding the problems of undesirable wear and degradation of NVH performance of the winding 2.

[0063] It should be understood that the above embodiments are only exemplary and are not intended to limit the present application. Those skilled in the art can make various modifications and changes to the above embodiments under the teaching of the present application without departing from the scope of the present application. The technical solutions of the present application are further described below.

[0064] i. The present application also provides an electric machine comprising a motor stator according to the present application and a motor rotor cooperating with the motor stator.

[0065] ii. In the above specific embodiments, it is explained that the ring assembly 3 comprises a partition ring 31 and an end cover 32 which are manufactured separately and assembled and fixed together, the partition ring 31 comprises a first side wall 311, a first peripheral wall 312, a second peripheral wall 313 and a partition wall 314 formed integrally, and the end cover 32 comprises a second side wall 321, but the present application does not limit the structure and shape of the ring assembly 3.

[0066] In an alternative, the ring assembly 3 can have walls different from the above-mentioned shapes, as long as the internal space of the ring assembly 3 forms the first chamber 3c1 and the second chamber 3c2 which are separated from each other and not directly communicated.

[0067] In another alternative, the ring assembly 3 can be assembled together from a plurality of independent components different from the structure of the above-mentioned partition ring 31 and end cover 32, as long as the internal space of the ring assembly 3 forms the first chamber 3c1 and the second chamber 3c2 which are separated from each other and not directly communicated.

[0068] iii.It can be understood that the motor stator according to the present application mainly overcomes the problem of poor cooling effect caused by the long heat conduction path of the winding 2 in the prior art, and can greatly reduce the temperature of the part of the winding 2 located in the winding slot 1c of the stator. Moreover, since the flow path for the cooling oil to pass through does not need to be provided between the winding 2 and the iron core 1, a sufficient amount of adhesive can be added between the part of the winding 2 located in the winding slot 1c of the iron core 1 and the iron core 1, thereby ensuring the relative fixing relationship between the winding 2 and the iron core 1, and avoiding the problems of abrasion and deterioration of NVH performance caused by the shaking of the winding 2.

[0069] In addition, in the prior art of the first patent document described in the background art, since the cooling oil finally needs to flow into the motor cavity so that the motor stator and the motor rotor are both in an environment where cooling oil exists, very high performance requirements are put forward for the insulation structure and the sealing structure of each part of the motor, thereby increasing the cost. In contrast, in the motor stator according to the present application, the cooling fluid such as cooling oil can flow in the flow path formed by the internal space of the ring assembly 3 and the hollow flow path of the hairpin unit 2a of the winding 2, and it is not necessary to make other parts of the motor stator and the motor rotor be in an environment where cooling oil exists, thereby reducing the performance requirements for the related insulation structure and sealing structure (so that the insulation structure and sealing structure similar to the performance requirements of the traditional water-cooled motor can be adopted), thereby reducing the corresponding cost. Moreover, in the present application, the cooling fluid will not be stirred by the motor rotor, thereby avoiding the generation of stirring noise, and also avoiding the problems of cooling fluid loss, kinetic energy loss, etc. caused by the stirring of the cooling fluid by the motor rotor.

[0070] Further, the ring assembly 3 as a whole constitutes an additional part, which is convenient for transportation and assembly. Moreover, the partition ring 31 and the end cover 32 of the ring assembly 3 can be respectively manufactured by injection molding, thereby simplifying the manufacturing process. In addition, the inlet 32o1 and the outlet 32o2 of the end cover 32 can be sealingly connected with other parts, so that the oil circuit of the entire motor can be simplified, thereby reducing the corresponding cost. The partition ring 31 and the end cover 32 are fixed to each other by laser welding, thereby fully ensuring the structural firmness and reliability of the ring assembly 3, which is beneficial to large-scale industrial production.

Claims

1. An electric machine stator, characterized in that, Comprising: a core having a plurality of wire slots distributed at intervals in a circumferential direction of the motor stator; a winding including a plurality of hairpin units inserted into the wire slots, twisted side end portions of different hairpin units being connected to each other so that the winding forms a predetermined electric circuit, each of the hairpin units being formed with a hollow flow path, and the hollow flow path being formed with a first opening and a second opening at both twisted side end portions of the hairpin unit, respectively; and a ring assembly formed with an inlet and an outlet, and formed with a first chamber and a second chamber separated from each other, the inlet communicating the first chamber with an outside of the ring assembly, the outlet communicating the second chamber with the outside of the ring assembly, the twisted side end portion of each of the hairpin units being inserted into the ring assembly so that the first opening of each of the hairpin units communicates with the first chamber, thereby enabling a cooling fluid to be fed into the first opening from the first chamber and the hairpin unit via the inlet and the first chamber; the second opening communicates with the second chamber, thereby enabling the cooling fluid in the hairpin unit to be discharged from the second opening via the second chamber and the outlet. the ring assembly has a first side wall, a second side wall, a first peripheral wall, a second peripheral wall, and a partition wall fixed to each other, 2. The motor stator of claim 1, wherein, the first side wall and the second side wall extend along the circumferential direction and oppose each other in an axial direction of the motor stator, the first peripheral wall and the second peripheral wall extend along the circumferential direction and oppose each other in a radial direction of the motor stator, and an internal space enclosed by the first side wall, the second side wall, the first peripheral wall, and the second peripheral wall is partitioned into the first chamber and the second chamber by the partition wall. the ring assembly includes a partition ring and an end cover assembled and fixed together, 3. The motor stator of claim 2, wherein, the partition ring includes the first side wall, the first peripheral wall, the second peripheral wall, and the partition wall formed as one body, the end cover includes the second side wall, and the first peripheral wall, the second peripheral wall, and the partition wall stand up from the first side wall toward the second side wall and abut against the second side wall. the first side wall is formed with through holes through which the twisted side end portions of the hairpin units are sealingly inserted, and the twisted side end portions of the hairpin units connected to each other of a pair of the hairpin units are inserted through one corresponding through hole.

4. The motor stator of claim 3, wherein, the through hole includes a first end portion, an intermediate portion, and a second end portion communicating with each other, the intermediate portion is located between the first end portion and the second end portion in the axial direction, at least one peripheral wall of the first end portion is formed with a chamfer, and a peripheral wall of the second end portion forms a glue groove with the twisted side end portion.

5. The motor stator of claim 4, wherein, the peripheral wall of the second end portion and the twisted side end portion are connected together by a connecting portion formed by applying a bonding glue in the glue groove, and the connecting portion enables a seal between the peripheral wall of the second end portion and the twisted side end portion.

6. The motor stator of claim 5, wherein, a surface of the second side wall facing the first side wall is formed with a first mounting groove, a second mounting groove, and a third mounting groove, 7. An electrical machine stator according to any one of claims 3 to 6, characterised in that, ​ The first mounting groove is identical to the extension trajectory of the first peripheral wall, and the first peripheral wall is inserted and mounted in the first mounting groove, The second mounting groove is identical to the extension trajectory of the second peripheral wall, and the second peripheral wall is inserted and mounted in the second mounting groove, and The third mounting groove is identical to the extension trajectory of the partition wall, and the partition wall is inserted and mounted in the third mounting groove.

8. The motor stator of claim 7, wherein, A surface of the second peripheral wall, which faces away from the first peripheral wall, is formed with a protruding welding guide portion, and the extension trajectory of the welding guide portion is identical to the extension trajectories of the first mounting groove, the second mounting groove, and the third mounting groove, so that welding along the welding guide portion causes the partition ring and the end cover to be fixed together.

9. The motor stator of any one of claims 1 to 6, wherein, The hairpin unit includes a first insertion portion, a second insertion portion, a crown side end portion, a first twisted side end portion, and a second twisted side end portion that are fixed together, The first insertion portion and the second insertion portion each extend linearly in the axial direction of the motor stator, and the first insertion portion and the second insertion portion of the same hairpin unit are located in different wire grooves, One end portion of the first insertion portion and one end portion of the second insertion portion are connected via the crown side end portion, the other end portion of the first insertion portion is connected to the first twisted side end portion, and the other end portion of the second insertion portion is connected to the second twisted side end portion.

10. An electric machine characterized by A motor stator according to any one of claims 1 to 9.

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