Cooling structure of oil-cooled motor and oil-cooled motor

Abstract

The utility model relates to a cooling structure of an oil-cooled motor and the oil-cooled motor, and provides an innovative scheme for solving the problems of large occupied space, high cost and cooling dead angles existing in a stator cooling mode of an existing oil-cooled motor. And the drainage holes formed by laminating the open slots in the periphery of the stator punching sheet are combined, so that efficient cooling is realized. Drainage holes which are axially distributed at intervals are formed in the periphery of a mounting flange at the upper part of the stator core, and are communicated with cooling gaps between the through holes and the stator-shell; an oil inlet channel is arranged in the shell end cover, and external cooling oil is guided into a gap between the via hole and the bolt and is guided to the periphery of the stator through the drainage hole; an oil outlet channel is arranged at the bottom of the shell to complete oil circulation. And the drainage holes are distributed obliquely or alternately and are matched with the open slots formed by laminating the stator punching sheets to form circumferential covering cooling, so that dead angles are eliminated. The motor is compact in structure, is simplified in technology, achieves the global cooling through the integrated design, and is suitable for a high-power electric vehicle drive motor.

Description

Technical Field

[0001] This utility model relates to the field of motor technology, specifically to an oil-cooled motor cooling structure and an oil-cooled motor. Background Technology

[0002] As a core component of electric vehicles, the drive motor's system performance and reliability have attracted much attention. Currently, with the development of high-power electric vehicles, the thermal management performance of the motor has become an important aspect of motor development. A high-power motor with energy efficiency, high performance and excellent thermal properties has become a preferred choice in the electric vehicle industry.

[0003] Oil-cooled motors typically consist of a motor housing and a stator. The stator is bolted to the motor housing and includes a stator core and stator windings mounted on the stator core. Currently, stator core cooling often employs oil pipe spraying. However, this cooling method suffers from space requirements and high costs due to the oil pipes, and the presence of mounting flanges on the stator core creates blind spots in the spraying process, failing to meet the trends of motor compactness and cost control.

[0004] For example, CN114157081A discloses an oil-cooled motor stator assembly. This type of oil-cooled motor is equipped with an oil guide ring. One end of the oil guide ring is fitted and connected to one end face of the stator core, and the other end of the oil guide ring is fitted and connected to the inner wall of the rear housing end cover, forming an end oil spray for the stator core. An axially extending opening groove is provided on the outer circumference of the stator core to form an oil channel. Although this structure can achieve cooling of the motor stator to a certain extent, the setting of the oil guide ring will inevitably increase the axial length of the oil-cooled motor and the production cost. The axially extending oil channel is complex to manufacture and has high production process requirements, and the cooling effect at the through hole is weak. Summary of the Invention

[0005] The purpose of this utility model is to address the shortcomings of existing technologies by providing a cooling structure and an oil-cooled motor. This oil-cooled motor uses the bolt mounting holes of the stator lamination mounting flange as cooling oil channels. The mounting flange is provided with a through hole connecting to the inner cavity of the motor housing, which guides the cooling oil from the through hole to the outer periphery of the stator core, thereby fully cooling the outer periphery of the stator.

[0006] The specific technical solution adopted to achieve the purpose of this utility model is as follows:

[0007] A cooling structure for an oil-cooled motor includes a housing. One end of the housing is fixedly connected to a housing end cover to form a motor mounting cavity. A stator core is provided inside the motor mounting cavity. The stator core is formed by stacking stator laminations axially. Multiple radially extending mounting flanges are provided on its outer periphery. Fastening bolts pass through through holes opened on the mounting flanges to fix the stator core on the housing end cover. A cooling gap is formed between the stator core and the housing. A stator winding is embedded inside the stator core.

[0008] The cooling structure includes:

[0009] Drainage holes, which are axially spaced on at least one mounting flange located on the upper part of the stator core, connect the through holes to the electric cooling gap and guide the cooling oil from the through holes to the outer periphery of the stator core to cool the stator core.

[0010] The oil inlet channel is located inside the end cover of the housing. Its oil inlet end is connected to the oil inlet port provided on the outer periphery of the end cover of the housing, and its oil outlet end is connected to one end of the through hole with a drainage hole, so that the cooling oil is introduced from the outside of the oil-cooled motor into the gap between the through hole wall and the fastening bolt.

[0011] The oil outlet is located at the bottom of the housing, allowing cooling oil to be discharged from inside the motor housing cavity to the outside of the oil-cooled motor.

[0012] Preferably, the stator lamination is annular, and the drainage hole is formed by axially stacking open grooves provided on the outer periphery of the stator lamination.

[0013] Preferably, the housing end cover is provided with a positioning step for cooperating with the stator core. The screw of the fastening bolt passes through the through hole of the mounting flange and is threadedly engaged with the threaded hole provided on the positioning step, so as to fix the stator core in the motor mounting cavity. The outer periphery and axial free end of the stator core and the housing form a cooling gap.

[0014] Preferably, the positioning step is provided with an oil guide groove, which is connected to the through hole of the connecting drain hole and the oil outlet of the oil inlet channel, so that the cooling oil is introduced from the oil outlet of the oil inlet channel through the threaded hole into the gap between the through hole and the fastening bolt.

[0015] Preferably, the drainage hole is obliquely disposed on the outer periphery of the mounting flange.

[0016] Preferably, the drainage holes are alternately distributed on both sides of the outer periphery of the mounting flange.

[0017] Preferably, the slots on the same stator lamination are arranged in the same circumferential direction.

[0018] Preferably, the oil inlet channel includes a connecting oil channel, a radial oil channel, and an axial oil channel. The oil inlet end of the connecting oil channel is connected to an oil inlet provided on the outer periphery of the end cover of the housing, and the oil outlet end is connected to the radial oil channel. The oil outlet end of the radial oil channel is connected to the oil inlet end of the axial oil channel, and the oil outlet end of the axial oil channel is connected to the through hole of the connecting drainage hole.

[0019] Preferably, the stator laminations are formed by stamping silicon steel sheets.

[0020] An oil-cooled motor includes the aforementioned oil-cooled motor cooling structure.

[0021] The beneficial effects of this utility model are as follows:

[0022] 1. Integrated structure and small space occupation: By reusing the through holes on the mounting flange as cooling oil holes and using radial openings to form drainage holes, compared with the cooling method of setting a spray device at the stator end, the contact range between the cooling oil and the stator in this application is larger, and additional components such as oil pipes are eliminated. While improving the cooling effect, it meets the requirements of compactness and integration of oil-cooled motors.

[0023] 2. Full-area cooling coverage, eliminating dead zones: The drainage holes connect the through holes to the inner cavity of the motor housing. The drainage holes are alternately distributed on both sides of the outer periphery of the mounting flange. Cooling oil flows to the outer periphery of the stator core through the drainage holes, realizing circumferential cooling coverage of the stator core, reducing cooling dead zones, and improving cooling efficiency.

[0024] 3. Simplified process and low cost: The stator laminations are integrally formed by stamping silicon steel sheets. Through holes and drainage holes are naturally formed during the stator lamination stacking process, without the need for additional processing. The production cost is low, and the standardized stamping process is suitable for large-scale production.

[0025] 4. Optimized cooling efficiency through directional airflow: The opening slots on the same stator lamination are arranged in the same circumferential direction, which guides the cooling oil to form a swirling effect, enhances the circulation flow of the oil in the inner cavity of the motor housing, and further improves the heat dissipation efficiency. Attached Figure Description

[0026] Figure 1 This is an exploded view of the structure of this utility model;

[0027] Figure 2 This is a cross-sectional view of the structure of this utility model;

[0028] Figure 3 This is a schematic diagram of the structure of the shell end cap in this utility model;

[0029] Figure 4 This is a schematic diagram of the stator core structure without opening slots in this utility model;

[0030] Figure 5 This is a schematic diagram of the stator core structure with an open slot in this utility model. Detailed Implementation

[0031] like Figures 1 to 5As shown, an oil-cooled motor cooling structure includes a housing 19. One end of the housing 19 is fixedly connected to a housing end cover 18 by bolts to form a motor mounting cavity. A stator core 2 is provided inside the motor mounting cavity. The stator core 2 is supported by a rotor shaft inside the stator core 2 in shaft holes opened in the housing 19 and the housing end cover 18. The stator core 2 is formed by axially stacking stator laminations 4. It has multiple radially extending mounting flanges 5 on its outer periphery. Fastening bolts 6 pass through through holes 7 opened on the mounting flanges 5 to fix the stator core 2 onto the housing end cover 18. In this embodiment, the housing end cover 18 has a fitting for cooperating with the stator core 2. The stator core 2 has a positioning step 12, on which a threaded hole 13 is provided to mate with the through hole 7. The threaded hole 13 is located at the radial clearance of the positioning step 12. Multiple fastening bolts 6 pass through the through hole 7 of the mounting flange 5. In actual production, the through hole 7 can be of any shape, such as a polygonal hole or a round hole, and it is threadedly engaged with the threaded hole 13 on the positioning step 12 to fix the stator core 2 on the housing end cover 18. The outer periphery and axial free end of the stator core 2 and the housing 19 form a cooling gap for the cooling oil to flow around the outer periphery of the stator core 2. The stator core 2 is embedded with stator windings.

[0032] The cooling structure includes: drainage holes 8, which are axially spaced on at least one mounting flange 5 located on the upper part of the stator core 2, connecting the through holes 7 with the electric cooling gap, for guiding cooling oil from the through holes 7 to the outer periphery of the stator core 2 to cool the stator core 2.

[0033] The stator lamination 4 is formed by stamping silicon steel sheet and is annular. The inner edge of the stator lamination 4 has a mounting groove for embedding the motor winding 3, and the outer edge has a radial extension portion. Each radial extension portion has a through hole. After axial stacking, they form a mounting flange 5 with through holes 7. The drainage hole 8 is formed by axially stacking open slots 81 on the outer periphery of the stator lamination 4. Stator laminations 4 with open slots 81 are stacked to form a group of stator laminations 4 with a certain axial thickness. Stator laminations 4 without open slots 81 are stacked to form a group of stator laminations 4 with a certain axial thickness. The two are alternately stacked to form drainage holes 8 axially spaced on the outer periphery of the mounting flange 5. In this embodiment, the open slots 81 are inclined. On the radial extension of the stator lamination 4, axially stacked drainage holes 8 are formed on the outer periphery of the mounting flange 5. The inclined drainage holes 8 facilitate the discharge of cooling oil at a lower pressure. The stator laminations 4 with opening slots 81 are stacked to form a group of stator laminations 4 with a certain axial thickness. The group of stator laminations 4 with drainage holes 8 is flipped to form a group of stator laminations 4 with drainage holes 8 distributed on the other side of the outer periphery of the mounting flange 5. The group of stator laminations 4 is stacked alternately to form drainage holes 8 that are alternately distributed on both sides of the outer periphery of the mounting flange 5. If there are two or more mounting flanges 5 with drainage holes 8, the opening slots 81 on the same stator lamination 4 are arranged in the same circumferential direction to facilitate the flow of coolant around the outer periphery of the stator core 2.

[0034] An oil inlet channel is located inside the end cover 18 of the housing. Its oil inlet end is connected to the oil inlet port 10 provided on the outer periphery of the end cover 18 of the housing, and its oil outlet end is connected to one end of the through hole 7 with the drainage hole 8, so that the cooling oil is introduced from the oil sump at the bottom of the electric drive housing outside the oil-cooled motor into the gap between the wall of the through hole 7 and the fastening bolt 6; an oil guide groove 14 is provided on the surface of the positioning step 12. The oil guide groove 14 is connected to the through hole 7 that connects to the drainage hole 8 and the oil outlet end of the oil inlet channel, so that the cooling oil is introduced from the oil outlet end of the oil inlet channel through the threaded hole 13 into the gap between the through hole 7 and the fastening bolt 6. Oil outlet 11 is located at the bottom of housing 19, allowing cooling oil to be discharged from the motor housing 1 cavity to the oil sump at the bottom of the electric drive housing outside the oil-cooled motor. Oil inlet, oil outlet 11 and oil sump form a circulating oil circuit. The oil inlet includes connecting oil channel 15, radial oil channel 16 and axial oil channel 17. The oil inlet end of the connecting oil channel 15 is connected to the oil inlet 10 provided on the outer periphery of the housing end cover 18, and the oil outlet end is connected to all radial oil channels 16. The oil outlet end of the radial oil channel 16 is connected to the oil inlet end of the axial oil channel 17. The oil outlet end of the axial oil channel 17 is connected to the through hole 7 of the connecting drain hole 8. The manufacturing process hole opened in the axial oil channel 17 is blocked by a plug.

[0035] An oil-cooled motor includes the oil-cooled motor cooling structure described above.

[0036] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications made to the present utility model by those skilled in the art without departing from the spirit of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A cooling structure for an oil-cooled motor, comprising a housing (19), one end of which is fixedly connected to a housing end cover (18) to form a motor mounting cavity, wherein a stator core (2) is provided in the motor mounting cavity, the stator core (2) being formed by axially stacking stator laminations (4), and having multiple radially extending mounting flanges (5) on its outer periphery, wherein fastening bolts (6) pass through through holes (7) opened on the mounting flanges (5) to fix the stator core (2) on the housing end cover (18), a cooling gap is formed between the stator core (2) and the housing (19), and a stator winding (3) is embedded in the stator core (2), characterized in that: The cooling structure includes: Drainage holes (8) are axially spaced on at least one mounting flange (5) located on the upper part of the stator core (2) to connect the through hole (7) with the cooling gap and to guide the cooling oil from the through hole (7) to the outer periphery of the stator core (2) to cool the stator core (2). The oil inlet channel is located inside the end cover (18) of the housing. Its oil inlet end is connected to the oil inlet (10) provided on the outer periphery of the end cover (18) of the housing, and its oil outlet end is connected to one end of the through hole (7) with the drain hole (8), so that the cooling oil is introduced from outside the oil-cooled motor into the gap between the wall of the through hole (7) and the fastening bolt (6). The oil outlet (11) is located at the bottom of the housing (19) to allow the cooling oil to be discharged from the motor housing (1) cavity to the outside of the oil-cooled motor.

2. The oil-cooled motor cooling structure according to claim 1, characterized by: The stator lamination (4) is annular, and the drainage hole (8) is formed by axially stacking the opening groove (81) provided on the outer periphery of the stator lamination (4).

3. The oil-cooled motor cooling structure according to claim 1, characterized by: The housing end cover (18) is provided with a positioning step (12) for cooperating with the stator core (2). The fastening bolt (6) passes through the through hole (7) of the mounting flange (5) and is threadedly engaged with the threaded hole (13) provided on the positioning step (12) to fix the stator core (2) on the housing end cover (18). The outer periphery and axial free end of the stator core (2) and the housing (19) form a cooling gap.

4. The oil-cooled motor cooling structure according to claim 3, characterized by: The positioning step (12) is provided with an oil guide groove (14), which is connected to the through hole (7) of the connecting drain hole (8) and the oil outlet of the oil inlet channel, so that the cooling oil is introduced from the oil outlet of the oil inlet channel through the threaded hole (13) into the gap between the through hole (7) and the fastening bolt (6).

5. The oil-cooled motor cooling structure according to claim 1, characterized by: The drainage hole (8) is inclinedly disposed on the outer periphery of the mounting flange (5).

6. The oil-cooled motor cooling structure according to claim 5, characterized by: The drainage holes (8) are alternately distributed on both sides of the outer periphery of the mounting flange (5).

7. The oil-cooled motor cooling structure according to claim 2, characterized by: The opening slots (81) on the same stator lamination (4) are arranged in the same circumferential direction.

8. The oil-cooled motor cooling structure of claim 1, wherein: The oil inlet channel includes a connecting oil channel (15), a radial oil channel (16), and an axial oil channel (17). The oil inlet end of the connecting oil channel (15) is connected to the oil inlet (10) provided on the outer periphery of the end cap (18) of the housing, and the oil outlet end is connected to the radial oil channel (16). The oil outlet end of the radial oil channel (16) is connected to the oil inlet end of the axial oil channel (17), and the oil outlet end of the axial oil channel (17) is connected to the through hole (7) of the connecting drainage hole (8).

9. The oil-cooled motor cooling structure of claim 1, wherein: The stator lamination (4) is formed by stamping silicon steel sheets.

10. An oil-cooled electric machine characterized by: An oil-cooled electric machine cooling structure comprising the oil-cooled electric machine cooling structure as claimed in any one of claims 1 to 9.

Images