Stator cooling oil circuit and motor
The stator cooling system in electric machines simplifies manufacturing by using housing channels instead of stator channels, ensuring consistent silicon steel sheet types and effective cooling.
Patent Information
- Application Number
- CN202421631847.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-10
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-07-10
AI Technical Summary
In the prior art, the cooling oil circuit design on the stator core is complicated, which increases the manufacturing difficulty and the punch type of silicon steel sheets, resulting in the complex overlapping process of the stator core.
The oil guide groove and oil passage are set on the outer jacket and inner sleeve of the motor housing, and an oil inlet port is set on the side wall of the outer jacket and the oil return port is set on the end cover of the motor to form a circulating cooling oil passage, and the stator core and coil are directly cooled to avoid opening the oil guide groove on the stator.
The complexity of stator core manufacturing is reduced, the punching type of silicon steel sheets is ensured, and the overlapping process of stator core is simplified.
Smart Images
Figure CN223109786U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of motor cooling, in particular to a stator cooling oil circuit and a motor. Background Art
[0002] A motor is the core driving unit of a new energy vehicle. During its operation, due to various losses, heat will be generated, so it needs to be cooled to ensure its normal operation. The main heat-generating parts of the motor are the stator and winding of the motor. Currently, there are three types of cooling media for motors: air, water, and oil. Among them, oil cooling can achieve direct cooling and has the best cooling effect, which is the current trend in the industry.
[0003] For the cooling of the stator, the current oil circuit is mainly designed on the stator core. Since the stator core is formed by stamping and laminating a number of silicon steel sheets, the oil circuit structure on the stator core is relatively complex, including a number of oil guiding grooves opened axially, radially, and circumferentially. This will undoubtedly increase the types of silicon steel sheet stamping, resulting in a more complex subsequent lamination process; and this oil circuit structure requires a special oil guiding groove to be arranged on the stator end face, thereby increasing the complexity of stator core manufacturing. Summary of the Utility Model
[0004] The utility model provides a stator cooling oil circuit and a motor, which solve the problems in the prior art that designing a cooling oil circuit on the stator core increases the complexity of stator core manufacturing.
[0005] The technical solution of the utility model is realized as follows:
[0006] In the first aspect of the utility model, a stator cooling oil circuit is provided. The stator is arranged in the shell of the motor. The shell includes an outer sleeve and an inner sleeve. The inner wall of the outer sleeve is hermetically connected to the outer wall of the inner sleeve. The inner wall of the inner sleeve abuts against the outer wall of the stator (sealing and abutting to form an oil circuit); a number of oil guiding grooves are provided on the side walls of the outer sleeve and / or the inner sleeve, and the oil guiding grooves on the side wall of the inner sleeve are communicated with the oil guiding grooves on the side wall of the outer sleeve through an oil passage; an oil inlet is provided on the outer sleeve, and the oil inlet is communicated with the oil guiding groove on the side wall of the inner sleeve or the side wall of the outer sleeve to form an oil inlet oil circuit. A cooling oil circuit is formed between the oil guiding groove on the side wall of the inner sleeve and the stator; an oil return port is provided on the outer sleeve or the motor end cover, and the oil return port is communicated with the cooling oil circuit to form an oil return oil circuit. The oil inlet oil circuit, the cooling oil circuit, and the oil return oil circuit are sequentially communicated to form a circulating oil circuit.
[0007] The utility model cools the stator core and the coils at both ends by arranging a plurality of oil guiding grooves and oil channels on the outer sleeve and the inner sleeve of the motor housing, opening an oil inlet on the side wall of the outer sleeve, and arranging an oil return port on the outer sleeve or the motor end cover. Cooling oil is injected into the oil guiding grooves and oil channels of the outer sleeve and the inner sleeve through the oil inlet to cool the stator core and the coils at both ends, and then the cooling oil is recovered through the oil return port. After the cooling oil is recovered and cooled, it is pumped into the oil inlet through an oil pump to form a circulating cooling oil circuit. The stator cooling oil circuit of the utility model does not need to open oil guiding grooves on the stator, which can ensure the consistency of the punching types of silicon steel sheets, reduce the complexity of punching and stacking the stator core, and thus reduce the complexity of manufacturing the stator core.
[0008] Preferably, a plurality of first oil guiding grooves are arranged on the inner wall of the inner sleeve, and the positions of the first oil guiding grooves correspond to the position of the stator core. The plurality of first oil guiding grooves are distributed along the circumferential direction of the inner sleeve, and both ends of the plurality of first oil guiding grooves are respectively communicated with the oil inlet and the oil return port. Cooling oil is injected into the first oil guiding grooves through the oil inlet, and the outer wall of the stator core can be directly cooled. The cooled cooling oil is then recovered through the oil return port to form a circulating cooling oil circuit.
[0009] Preferably, a first annular oil groove and a second annular oil groove are arranged on the outer wall of the inner sleeve, and the positions of the first annular oil groove and the second annular oil groove respectively correspond to the positions of both ends of the plurality of first oil guiding grooves. A plurality of first communication holes are opened on the arc surface of the first annular oil groove, and the plurality of first communication holes are respectively communicated with one ends of the plurality of first oil guiding grooves. A plurality of second communication holes are opened on the arc surface of the second annular oil groove, and the plurality of second communication holes are respectively communicated with the other ends of the plurality of first oil guiding grooves. The first annular oil groove is communicated with the oil inlet, and the second annular oil groove is communicated with the oil return port. After the cooling oil introduced from the oil inlet enters the first annular oil groove, it enters one ends of the plurality of first oil guiding grooves through the plurality of first communication holes, and then flows from one end of the first oil guiding groove to the other end (when the cooling oil circulates in the first oil guiding groove, it directly contacts the outer wall of the stator core, thereby cooling the stator core), and then converges into the second annular oil groove through the second communication holes at the other end of the first oil guiding groove, and finally is recovered through the oil return port.
[0010] Further, the outer wall of the inner sleeve is provided with a third annular oil groove and a fourth annular oil groove. The positions of the third annular oil groove and the fourth annular oil groove correspond to the positions of the coils at both ends of the stator core respectively. The third annular oil groove is communicated with the first annular oil groove through a second oil guiding groove, and the fourth annular oil groove is communicated with the second annular oil groove through a third oil guiding groove. A plurality of first oil spraying holes are formed on the arc surface of the third annular oil groove, and a plurality of second oil spraying holes are formed on the arc surface of the fourth annular oil groove. After the cooling oil introduced from the oil inlet enters the first annular oil groove, a part of it enters the first oil guiding groove through the first communication hole to cool the stator core, and the other part enters the third annular oil groove through the second oil guiding groove, and then is sprayed out through a plurality of first oil spraying holes on the third annular oil groove to spray and cool the coil at one end of the stator core. The cooling oil that enters the second annular oil groove through the first oil guiding groove and the second communication hole enters the fourth annular oil groove through the third oil guiding groove, and then is sprayed out through a plurality of second oil spraying holes on the fourth annular oil groove to spray and cool the coil at the other end of the stator core. The cooling oil after spraying and cooling converges at the lowest point of the motor installation, and finally is recovered through the oil return port.
[0011] Optionally, the inner wall of the outer sleeve is provided with a first annular oil groove and a second annular oil groove. The positions of the first annular oil groove and the second annular oil groove correspond to the positions of both ends of a plurality of first oil guiding grooves respectively. A plurality of first communication holes communicated with the first annular oil groove are formed on the side wall of the inner sleeve, and a plurality of the first communication holes are respectively communicated with one end of a plurality of first oil guiding grooves. A plurality of second communication holes communicated with the second annular oil groove are formed on the side wall of the inner sleeve, and a plurality of the second communication holes are respectively communicated with the other end of a plurality of first oil guiding grooves. The first annular oil groove is communicated with the oil inlet, and the second annular oil groove is communicated with the oil return port.
[0012] Further, the inner wall of the outer sleeve is provided with a third annular oil groove and a fourth annular oil groove. The positions of the third annular oil groove and the fourth annular oil groove correspond to the positions of the coils at both ends of the stator core respectively. The third annular oil groove is communicated with the first annular oil groove through a second oil guiding groove, and the fourth annular oil groove is communicated with the second annular oil groove through a third oil guiding groove. A plurality of first oil spraying holes communicated with the third annular oil groove are formed on the side wall of the inner sleeve, and a plurality of second oil spraying holes communicated with the fourth annular oil groove are formed on the side wall of the inner sleeve.
[0013] In a second aspect of the present invention, there is provided a motor, including a housing, wherein a stator and a rotor are arranged inside the housing, and the above-mentioned stator cooling oil circuit is arranged on the housing. Description of the Drawings
[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.
[0015] Figure 1 Structural schematic diagram of a stator cooling oil circuit of the present invention;
[0016] Figure 2 External structural schematic diagram of the inner sleeve in the embodiment of the present invention;
[0017] Figure 3 Internal structural schematic diagram of the inner sleeve in the embodiment of the present invention;
[0018] In the figure: 1. Outer sleeve; 2. Inner sleeve; 3. Oil inlet; 4. End cover; 5. Oil return port; 6. First oil guide groove; 7. Stator core; 8. First annular oil groove; 9. Second annular oil groove; 10. First communication hole; 11. Second communication hole; 12. Third annular oil groove; 13. Fourth annular oil groove; 14. Coil; 15. Second oil guide groove; 16. Third oil guide groove; 17. First injection hole; 18. Second injection hole. Specific embodiments
[0019] The following will clearly and completely describe the technical solutions of the present invention in combination with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.
[0020] Refer to Figures 1 to 3, an embodiment of the present utility model provides a stator cooling oil circuit. The stator is arranged inside the housing of the motor. The housing includes an outer sleeve 1 and an inner sleeve 2. The inner wall of the outer sleeve 1 is hermetically welded to the outer wall of the inner sleeve 2 (for closing the oil groove between the inner wall of the outer sleeve 1 and the outer wall of the inner sleeve 2, thereby forming a sealed oil passage). The inner wall of the inner sleeve 2 abuts against the outer wall of the stator. A plurality of oil guiding grooves are provided on the side walls of the outer sleeve 1 and / or the inner sleeve 2, and the oil guiding grooves on the side wall of the inner sleeve 2 are communicated with the oil guiding grooves on the side wall of the outer sleeve 1 through an oil passage. An oil inlet 3 is provided on the outer sleeve 1. The oil inlet 3 is communicated with the oil guiding groove on the side wall of the inner sleeve 2 or the outer sleeve 1 to form an oil inlet oil circuit. A cooling oil circuit is formed between the oil guiding groove on the side wall of the inner sleeve 2 and the stator. An oil return port 5 is provided on the outer sleeve 1 or the motor end cover 4 (the specific installation position can be adjusted according to the actual installation situation of the motor). The oil return port 5 is communicated with the cooling oil circuit to form an oil return oil circuit. The oil inlet oil circuit, the cooling oil circuit, and the oil return oil circuit are sequentially communicated to form a circulating oil circuit.
[0021] In the present utility model, a plurality of oil guiding grooves and oil passages are provided on the outer sleeve 1 and the inner sleeve 2 of the motor housing. An oil inlet 3 is opened on the side wall of the outer sleeve 1, and an oil return port 5 is provided on the outer sleeve 1 or the motor end cover 4. Cooling oil is injected into the oil guiding grooves and oil passages of the outer sleeve 1 and the inner sleeve 2 through the oil inlet 3 to cool the stator core 7 and the coils 14 at both ends. Then, the cooling oil is recovered through the oil return port 5. After being cooled and recovered, the cooling oil is pumped into the oil inlet 3 through an oil pump to form a circulating cooling oil circuit. The stator cooling oil circuit of the present utility model does not need to open oil guiding grooves on the stator, which can ensure the consistency of the punching types of silicon steel sheets, reduce the complexity of punching and stacking of the stator core 7, and thus reduce the complexity of manufacturing the stator core 7.
[0022] As a preferred embodiment of the present utility model, a plurality of first oil guiding grooves 6 are provided on the inner wall of the inner sleeve 2 (the grooving direction of the first oil guiding grooves 6 is parallel to the axial direction of the stator). The positions of the first oil guiding grooves 6 correspond to the positions of the stator core 7. The plurality of first oil guiding grooves 6 are evenly distributed along the circumferential direction of the inner sleeve 2. Both ends of the plurality of first oil guiding grooves 6 are respectively communicated with the oil inlet 3 and the oil return port 5. By injecting cooling oil into the first oil guiding grooves 6 through the oil inlet 3, the outer wall of the stator core 7 can be directly cooled, and the cooled cooling oil is recovered through the oil return port 5 to form a circulating cooling oil circuit.
[0023] As a preferred embodiment of the present utility model, the outer wall of the inner sleeve 2 is provided with a first annular oil groove 8 and a second annular oil groove 9, and the positions of the first annular oil groove 8 and the second annular oil groove 9 respectively correspond to the two ends of a plurality of first oil guiding grooves 6; a plurality of first communication holes 10 are formed in the arc surface of the first annular oil groove 8 (the number of the first communication holes 10 is the same as that of the first oil guiding grooves 6, and the positions of the first communication holes 10 correspond to one end of the first oil guiding grooves 6), and a plurality of the first communication holes 10 are respectively communicated with one end of a plurality of first oil guiding grooves 6; a plurality of second communication holes 11 are formed in the arc surface of the second annular oil groove 9 (the number of the second communication holes 11 is the same as that of the first oil guiding grooves 6, and the positions of the second communication holes 11 correspond to the other end of the first oil guiding grooves 6), and a plurality of the second communication holes 11 are respectively communicated with the other end of a plurality of first oil guiding grooves 6; the first communication holes 10 and the second communication holes 11 are both radially formed; the first annular oil groove 8 is communicated with the oil inlet 3, and the second annular oil groove 9 is communicated with the oil return port 5; after the cooling oil introduced from the oil inlet 3 enters the first annular oil groove 8, it enters one end of a plurality of first oil guiding grooves 6 through a plurality of first communication holes 10, and then flows from one end of the first oil guiding grooves 6 to the other end (when the cooling oil flows in the first oil guiding grooves 6, it directly contacts the outer wall of the stator core 7, so as to cool the stator core 7), and then converges into the second annular oil groove 9 through the second communication holes 11 at the other end of the first oil guiding grooves 6, and finally is recovered through the oil return port 5.
[0024] Further, an outer wall of the inner sleeve 2 is provided with a third annular oil groove 12 and a fourth annular oil groove 13. Positions of the third annular oil groove 12 and the fourth annular oil groove 13 respectively correspond to positions of coils 14 at two ends of a stator core 7. The third annular oil groove 12 is communicated with the first annular oil groove 8 through a second oil guiding groove 15. The fourth annular oil groove 13 is communicated with the second annular oil groove 9 through a third oil guiding groove 16 (the second oil guiding groove 15 / the third oil guiding groove 16 is opened along an axial direction of the stator). A plurality of first oil spraying holes 17 are opened on an arc surface of the third annular oil groove 12. A plurality of second oil spraying holes 18 are opened on an arc surface of the fourth annular oil groove 13 (the first oil spraying holes 17 and the second oil spraying holes 18 are both opened along a radial direction of the stator, and a plurality of the first oil spraying holes 17 / the second oil spraying holes 18 are uniformly distributed along a circumferential direction of the stator); after the cooling oil introduced from an oil inlet 3 enters the first annular oil groove 8, a part of the cooling oil enters a first oil guiding groove 6 through a first communication hole 10 to cool the stator core 7, and another part of the cooling oil enters the third annular oil groove 12 through the second oil guiding groove 15, and then is sprayed out through a plurality of the first oil spraying holes 17 on the third annular oil groove 12 to perform spray cooling on the coil 14 at one end of the stator core 7; the cooling oil entering the second annular oil groove 9 through the first oil guiding groove 6 and a second communication hole 11 enters the fourth annular oil groove 13 through the third oil guiding groove 16, and then is sprayed out through a plurality of the second oil spraying holes 18 on the fourth annular oil groove 13 to perform spray cooling on the coil 14 at the other end of the stator core 7; the cooling oil after spray cooling converges at a lowest point where the motor is installed, and finally is recovered through an oil return port 5.
[0025] As an optionally implemented scheme of the present utility model (this implemented scheme is not shown in the attached drawings of this embodiment), an inner wall of the outer sleeve 1 is provided with a first annular oil groove 8 and a second annular oil groove 9. Positions of the first annular oil groove 8 and the second annular oil groove 9 respectively correspond to positions of two ends of a plurality of first oil guiding grooves 6; a plurality of first communication holes 10 communicated with the first annular oil groove 8 are opened on a side wall of the inner sleeve 2, and a plurality of the first communication holes 10 are respectively communicated with one ends of a plurality of the first oil guiding grooves 6; a plurality of second communication holes 11 communicated with the second annular oil groove 9 are opened on the side wall of the inner sleeve 2, and a plurality of the second communication holes 11 are respectively communicated with the other ends of a plurality of the first oil guiding grooves 6; the first annular oil groove 8 is communicated with the oil inlet 3, and the second annular oil groove 9 is communicated with the oil return port 5.
[0026] Further, the inner wall of the outer sleeve 1 is provided with a third annular oil groove 12 and a fourth annular oil groove 13. The positions of the third annular oil groove 12 and the fourth annular oil groove 13 correspond to the positions of the coils 14 at both ends of the stator core 7 respectively. The third annular oil groove 12 is communicated with the first annular oil groove 8 through a second oil guiding groove 15, and the fourth annular oil groove 13 is communicated with the second annular oil groove 9 through a third oil guiding groove 16. A plurality of first oil spraying holes 17 communicating with the third annular oil groove 12 are formed in the side wall of the inner sleeve 2, and a plurality of second oil spraying holes 18 communicating with the fourth annular oil groove 13 are formed in the side wall of the inner sleeve 2.
[0027] The annular oil groove in the present utility model can be arranged on the inner wall of the outer sleeve 1 or on the outer wall of the inner sleeve 2, and can be flexibly selected according to the actual situation. The accompanying drawings of this embodiment only take the annular oil groove arranged on the outer wall of the inner sleeve 2 as an example.
[0028] A second aspect of the embodiment of the present utility model provides a motor, including a housing. A stator and a rotor are arranged inside the housing, and the above-mentioned stator cooling oil circuit is arranged on the housing.
[0029] The circulation process of the stator cooling oil circuit in this embodiment is as follows:
[0030] First, the cooling oil in the fuel tank is pumped into the oil inlet 3 on the side wall of the outer sleeve 1 by a oil pump, and then enters the first annular oil groove 8. A part of the cooling oil enters the third annular oil groove 12 through the second oil guiding groove 15, and then is sprayed out through a plurality of first oil spraying holes 17 on the third annular oil groove 12 to spray-cool the coil 14 at one end of the stator core 7; another part of the cooling oil respectively enters a plurality of first oil guiding grooves 6 through a plurality of first communication holes 10 on the first annular oil groove 8 to cool the stator core 7, and then respectively converges into the second annular oil groove 9 through a plurality of second communication holes 11, and then enters the fourth annular oil groove 13 through the third oil guiding groove 16, and then is sprayed out through a plurality of second oil spraying holes 18 on the fourth annular oil groove 13 to spray-cool the coil 14 at the other end of the stator core 7; the cooling oil after spray-cooling converges at the lowest point where the motor is installed, and enters the oil return pipe through the oil return port 5, and finally is recovered to the fuel tank through the oil return pipe to complete the circulation of the stator cooling oil circuit.
[0031] The above are only the preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.
Claims
1. A stator cooling oil circuit, the stator being disposed within a housing of a motor, characterized in that, The housing includes an outer sleeve (1) and an inner sleeve (2). The inner wall of the outer sleeve (1) is sealingly connected to the outer wall of the inner sleeve (2), and the inner wall of the inner sleeve (2) abuts against the outer wall of the stator. A plurality of oil guiding grooves are provided on the side walls of the outer sleeve (1) and / or the inner sleeve (2), and the oil guiding grooves on the side wall of the inner sleeve (2) are communicated with the oil guiding grooves on the side wall of the outer sleeve (1) through oil channels. An oil inlet (3) is provided on the outer sleeve (1), and the oil inlet (3) is communicated with the oil guiding groove on the side wall of the inner sleeve (2) or the outer sleeve (1) to form an oil inlet oil path. A cooling oil path is formed between the oil guiding groove on the side wall of the inner sleeve (2) and the stator. An oil return port (5) is provided on the outer sleeve (1) or the motor end cover (4), and the oil return port (5) is communicated with the cooling oil path to form an oil return oil path. The oil inlet oil path, the cooling oil path, and the oil return oil path are sequentially communicated to form a circulating oil path.
2. The stator cooling oil circuit according to claim 1, characterized in that, A plurality of first oil guiding grooves (6) are provided on the inner wall of the inner sleeve (2). The positions of the first oil guiding grooves (6) correspond to the positions of the stator core (7). The plurality of first oil guiding grooves (6) are circumferentially distributed along the inner sleeve (2), and both ends of the plurality of first oil guiding grooves (6) are respectively communicated with the oil inlet (3) and the oil return port (5).
3. A stator cooling oil circuit according to claim 2, wherein A first annular oil groove (8) and a second annular oil groove (9) are provided on the outer wall of the inner sleeve (2). The positions of the first annular oil groove (8) and the second annular oil groove (9) respectively correspond to the positions of both ends of the plurality of first oil guiding grooves (6). A plurality of first communication holes (10) are provided on the arc surface of the first annular oil groove (8), and the plurality of first communication holes (10) are respectively communicated with one ends of the plurality of first oil guiding grooves (6). A plurality of second communication holes (11) are provided on the arc surface of the second annular oil groove (9), and the plurality of second communication holes (11) are respectively communicated with the other ends of the plurality of first oil guiding grooves (6). The first annular oil groove (8) is communicated with the oil inlet (3), and the second annular oil groove (9) is communicated with the oil return port (5).
4. The stator cooling oil circuit according to claim 3, characterized in that, A third annular oil groove (12) and a fourth annular oil groove (13) are provided on the outer wall of the inner sleeve (2). The positions of the third annular oil groove (12) and the fourth annular oil groove (13) respectively correspond to the positions of the coils (14) at both ends of the stator core (7). The third annular oil groove (12) is communicated with the first annular oil groove (8) through a second oil guiding groove (15), and the fourth annular oil groove (13) is communicated with the second annular oil groove (9) through a third oil guiding groove (16). A plurality of first oil spraying holes (17) are provided on the arc surface of the third annular oil groove (12), and a plurality of second oil spraying holes (18) are provided on the arc surface of the fourth annular oil groove (13).
5. The stator cooling oil circuit according to claim 2, wherein The inner wall of the outer sleeve (1) is provided with a first annular oil groove (8) and a second annular oil groove (9), and the positions of the first annular oil groove (8) and the second annular oil groove (9) respectively correspond to the two ends of a plurality of first oil guiding grooves (6); a plurality of first communication holes (10) communicating with the first annular oil groove (8) are formed in the side wall of the inner sleeve (2), and the plurality of first communication holes (10) respectively communicate with one ends of the plurality of first oil guiding grooves (6); a plurality of second communication holes (11) communicating with the second annular oil groove (9) are formed in the side wall of the inner sleeve (2), and the plurality of second communication holes (11) respectively communicate with the other ends of the plurality of first oil guiding grooves (6); the first annular oil groove (8) communicates with the oil inlet (3), and the second annular oil groove (9) communicates with the oil return port (5).
6. The stator cooling oil circuit according to claim 5, wherein, The inner wall of the outer sleeve (1) is provided with a third annular oil groove (12) and a fourth annular oil groove (13), the positions of the third annular oil groove (12) and the fourth annular oil groove (13) respectively correspond to the positions of the coils (14) at both ends of the stator core (7), the third annular oil groove (12) communicates with the first annular oil groove (8) through a second oil guiding groove (15), the fourth annular oil groove (13) communicates with the second annular oil groove (9) through a third oil guiding groove (16), a plurality of first oil injection holes (17) communicating with the third annular oil groove (12) are formed in the side wall of the inner sleeve (2), and a plurality of second oil injection holes (18) communicating with the fourth annular oil groove (13) are formed in the side wall of the inner sleeve (2).
7. A motor, characterized in that, It includes a housing, a stator and a rotor are arranged inside the housing, and the stator cooling oil circuit described in any one of claims 1 to 6 is arranged on the housing.