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

Abstract

The invention 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. The method specifically comprises the steps that drainage holes which are axially distributed at intervals are formed in the periphery of a mounting flange at the upper part of a stator core, and the drainage holes are communicated with cooling gaps between the through holes and a 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 structure is compact, the process is simplified, global cooling is realized through integrated design, the production cost is reduced, and the motor is suitable for a high-power electric vehicle driving motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to an oil-cooled motor cooling structure and an oil-cooled motor. Background Art

[0002] As the core component of electric vehicles, the drive motor has attracted much attention for its system performance and reliability. Under the background of the high-power development of electric vehicles, the thermal management performance of the motor has become an important part of motor development. A high-power motor with energy-saving, high efficiency and excellent thermal performance has become the favorite of the electric vehicle industry.

[0003] Oil-cooled motors usually include a motor housing and a stator, wherein the stator is fixed to the motor housing by bolts, and the stator includes a stator core and a stator winding embedded in the stator core. At present, the cooling of the stator core is often done by spraying with oil pipes, but this cooling method has the disadvantages of space occupied by the installation of the oil pipes, high cost, and the stator core has an installation flange, so there is a dead angle for spraying, which does not meet the development trend of compact motors and cost control.

[0004] For example, CN114157081A discloses an oil-cooled motor stator assembly, in which an oil guide ring is provided, 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 of the stator core, and an axially extending open groove is provided on the outer cylindrical surface of the stator core to form an oil channel. Although this structure can cool the motor stator to a certain extent, the provision of the oil guide ring will inevitably increase the axial length and production cost of the oil-cooled motor, and the provision of the axially extending oil channel is complex to manufacture and has high production process requirements, and the cooling effect at the through hole is relatively weak. Summary of the invention

[0005] The purpose of the present invention is to provide an oil-cooled motor cooling structure and an oil-cooled motor in view of the corresponding deficiencies in the prior art. The oil-cooled motor uses the bolt mounting holes of the stator punching mounting flange as cooling oil channels, and the mounting flange is provided with drainage holes connecting the through holes and the inner cavity of the motor housing, which are used to guide the cooling oil from the through holes to the outer periphery of the stator core, thereby fully cooling the outer periphery of the stator.

[0006] The specific technical solutions adopted for the purpose of the present invention are as follows: An oil-cooled motor cooling structure comprises a housing, one end of the housing is fixedly connected to the housing end cover to form a motor installation cavity, a stator core is arranged in the motor installation cavity, the stator core is formed by axially stacking stator punching sheets, a plurality of radially extending installation flanges are arranged on the outer circumference, fastening bolts pass through through holes provided on the installation flanges, and the stator core is fixedly installed on the housing end cover, a cooling gap is formed between the stator core and the housing, and a stator winding is embedded in the stator core; The cooling structure comprises: The drainage holes are axially spaced and distributed on the outer periphery of at least one mounting flange located on the upper part of the stator core, connecting the through holes with the electric cooling gap, and used to guide the cooling oil to flow from the through holes to the outer periphery of the stator core to cool the stator core; An oil inlet passage is arranged in the housing end cover, an oil inlet end of which is communicated with an oil inlet port arranged on the outer periphery of the housing end cover, and an oil outlet end of which is communicated with one end of a through hole provided with a drainage hole, so that cooling oil is introduced from the outside of the oil-cooled motor into the gap between the through hole wall and the fastening bolt; The oil outlet channel is arranged at the bottom of the housing to guide the cooling oil from the motor housing cavity to the outside of the oil-cooled motor.

[0007] Preferably, the stator punching sheet is annular, and the drainage hole is formed by axially stacking open grooves arranged on the outer periphery of the stator punching sheet.

[0008] Preferably, a positioning step for matching the stator core is provided in the shell end cover, and the screw of the fastening bolt passes through the through hole of the mounting flange and is threadedly matched with the threaded hole provided on the positioning step, so that the stator core is fixedly installed in the motor mounting cavity, and a cooling gap is formed between the outer periphery and axial free end of the stator core and the shell.

[0009] Preferably, an oil guide groove is provided on the positioning step, and the oil guide groove is connected to the through hole connected to the drainage hole 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 into the gap between the through hole and the fastening bolt.

[0010] Preferably, the drainage holes are obliquely arranged on the outer circumference of the mounting flange.

[0011] Preferably, the drainage holes are alternately spaced and distributed on both sides of the outer circumference of the mounting flange.

[0012] Preferably, the open slots on the same stator punching sheet are arranged along the same circumferential direction.

[0013] Preferably, the oil inlet passage includes a connecting oil passage, a radial oil passage, and an axial oil passage; the oil inlet end of the connecting oil passage is connected to the oil inlet port arranged on the outer periphery of the shell end cover, and the oil outlet end is connected to the radial oil passage; the oil outlet end of the radial oil passage is connected to the oil inlet end of the axial oil passage, and the oil outlet end of the axial oil passage is connected to the through hole of the connecting drainage hole.

[0014] Preferably, the stator punching sheets are formed by stamping silicon steel sheets.

[0015] An oil-cooled motor comprises the oil-cooled motor cooling structure as claimed in any one of claims 1 to 9.

[0016] The beneficial effects of the present invention are as follows: 1. Integrated structure, 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 end of the stator, the contact range between the cooling oil and the stator of the present application is larger, and additional components such as oil pipes are eliminated, thereby improving the cooling effect while meeting the compactness and integration requirements of oil-cooled motors.

[0017] 2. Full coverage cooling, eliminating dead corners: The drainage holes connect the through holes and the inner cavity of the motor housing. The drainage holes are alternately distributed on both sides of the outer periphery of the mounting flange. The cooling oil flows to the outer periphery of the stator core through the drainage holes, realizing circumferential coverage cooling of the stator core, reducing cooling dead corners and improving cooling efficiency.

[0018] 3. Simplified process and low cost: The stator punching sheets are formed in one piece by stamping silicon steel sheets. The via holes and drainage holes are naturally formed during the lamination process of the stator punching sheets. No additional processing is required, the production cost is low, and the standardized stamping process is suitable for large-scale production.

[0019] 4. Directional flow guidance optimizes cooling efficiency: The open slots on the same stator punching sheet are arranged along the same circumferential direction to guide the cooling oil to form a swirl effect, enhance the circulation fluidity of the oil in the inner cavity of the motor housing, and further improve the heat dissipation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is an exploded schematic diagram of the structure of the present invention; Figure 2 is a cross-sectional view of the structure of the present invention; Figure 3 It is a schematic diagram of the structure of the shell end cover in the present invention; Figure 4 It is a schematic diagram of the structure of the stator core without open slots in the present invention; Figure 5 It is a schematic diagram of the structure of the stator core with open slots in the present invention. DETAILED DESCRIPTION

[0021] 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 the housing end cover 18 by bolts to form a motor installation cavity, a stator core 2 is arranged in the motor installation cavity, the stator core 2 is supported in the shaft hole opened in the housing 19 and the housing end cover 18 through the rotor shaft in the stator core 2, the stator core 2 is formed by axially stacking stator punchings 4, a plurality of radially extending mounting flanges 5 are arranged on the outer periphery, and the fastening bolts 6 pass through the through holes 7 opened on the mounting flanges 5 to fix the stator core 2 on the housing end cover 18. In this embodiment, the housing end cover 18 is provided with a stator core 2 for cooperating with the stator core 2. The positioning step 12 of the stator core 2 is provided with a threaded hole 13 matched with the through hole 7, and the threaded hole 13 is located at the radial yield position of the positioning step 12. A plurality of 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 circular hole, and is threadedly matched 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 for cooling oil to flow around the outer periphery of the stator core 2, and the stator core 2 is embedded with a stator winding.

[0022] The cooling structure comprises: drainage holes 8, which are axially spaced and distributed on the outer periphery of at least one mounting flange 5 located on the upper part of the stator core 2, connecting the through hole 7 with the electric cooling gap, and used 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 stator punching sheet 4 is formed by stamping silicon steel sheets and is annular in shape. The inner edge of the stator punching sheet 4 is provided with a mounting groove for embedding the motor winding 3, and the outer edge is provided with a radial extension portion. The radial extension portion is provided with a through hole, and after axial lamination, a mounting flange 5 with a through hole 7 is formed. The drainage hole 8 is formed by axial lamination of the open groove 81 arranged on the outer periphery of the stator punching sheet 4. The stator punching sheet 4 with the open groove 81 is laminated to form a group of stator punching sheets 4 with a certain axial thickness, and the stator punching sheet 4 without the open groove 81 is laminated to form a group of stator punching sheets 4 with a certain axial thickness. The two are alternately laminated to form the drainage holes 8 distributed axially at intervals on the outer periphery of the mounting flange 5. In this embodiment, the open groove 81 is inclined. On the radial extension of the stator punching sheet 4, axial stacking is formed to form a drainage hole 8 which is obliquely arranged on the outer periphery of the mounting flange 5. The obliquely arranged drainage hole 8 facilitates the discharge of the cooling oil at a lower pressure. The stator punching sheets 4 with open grooves 81 are stacked to form a group of stator punching sheets 4 with a certain axial thickness, which are flipped to form a group of stator punching sheets 4 with drainage holes 8 distributed and obliquely arranged on the other side of the outer periphery of the mounting flange 5. The concentrated stator punching sheets 4 are alternately stacked to form drainage holes 8 alternately distributed on both sides of the outer periphery of the mounting flange 5. If there are more than two mounting flanges 5 with drainage holes 8, the open grooves 81 on the same stator punching sheet 4 are arranged along the same circumferential direction to facilitate the flow of coolant around the outer periphery of the stator core 2.

[0023] The oil inlet passage is arranged in the housing end cover 18, and its oil inlet end is connected with the oil inlet port 10 arranged on the outer periphery of the housing end cover 18, and its oil outlet end is connected with one end of the through hole 7 provided with the drainage hole 8, so that the cooling oil is introduced from the oil pool at the bottom of the electric drive housing outside the oil-cooled motor into the gap between the through hole 7 wall and the fastening bolt 6; the surface of the positioning step 12 is provided with an oil guide groove 14, and the oil guide groove 14 is connected with the through hole 7 connected with the drainage hole 8 and the oil outlet end of the oil inlet passage, so that the cooling oil is introduced from the oil outlet end of the oil inlet passage through the threaded hole 13 into the gap between the through hole 7 and the fastening bolt 6. The oil outlet passage 11 is arranged at the bottom of the shell 19, so that the cooling oil is discharged from the cavity of the motor housing 1 to the oil pool at the bottom of the electric drive shell outside the oil-cooled motor. The oil inlet passage, the oil outlet passage 11 and the oil pool form a circulating oil circuit; the oil inlet passage includes a connecting oil passage 15, a radial oil passage 16 and an axial oil passage 17. The oil inlet end of the connecting oil passage 15 is connected to the oil inlet port 10 arranged on the outer periphery of the shell end cover 18, and the oil outlet end is connected to all the radial oil passages 16. The oil outlet end of the radial oil passage 16 is connected to the oil inlet end of the axial oil passage 17, and the oil outlet end of the axial oil passage 17 is connected to the through hole 7 of the connecting drainage hole 8. The manufacturing process hole opened in the axial oil passage 17 is blocked by a plug.

[0024] An oil-cooled motor comprises the above-mentioned oil-cooled motor cooling structure.

[0025] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A cooling structure for an oil-cooled motor, comprising a housing (19), one end of the housing (19) being fixedly connected to a housing end cover (18) to form a motor mounting cavity, a stator core (2) being arranged in the motor mounting cavity, the stator core (2) being formed by axially stacking stator punching sheets (4), a plurality of radially extending mounting flanges (5) being arranged on the outer periphery, a fastening bolt (6) passing through through holes (7) provided on the mounting flanges (5), the stator core (2) being fixedly mounted on the housing end cover (18), a cooling gap being formed between the stator core (2) and the housing (19), a stator winding (3) being embedded in the stator core (2), characterized in that: The cooling structure comprises: Guide holes (8) are axially spaced and distributed on the outer periphery of at least one mounting flange (5) located on the upper portion of the stator core (2), connecting the through hole (7) with the electric cooling gap, and used to guide cooling oil to flow from the through hole (7) to the outer periphery of the stator core (2) to cool the stator core (2); An oil inlet passage, which is arranged in the housing end cover (18), the oil inlet end of which is in communication with an oil inlet port (10) arranged on the outer periphery of the housing end cover (18), and the oil outlet end of which is in communication with one end of a through hole (7) provided with a drainage hole (8), so that cooling oil is introduced from the outside of the oil-cooled motor into the gap between the through hole (7) wall and the fastening bolt (6); An oil outlet passage (11) is arranged at the bottom of the housing (19) to allow cooling oil to be discharged from the cavity of the motor housing (1) to the outside of the oil-cooled motor.

2. The oil-cooled motor cooling structure according to claim 1, characterized in that: The stator punching sheet (4) is annular in shape, and the drainage hole (8) is formed by axially stacking open grooves (81) arranged on the outer periphery of the stator punching sheet (4).

3. The oil-cooled motor cooling structure according to claim 1, characterized in that: A positioning step (12) for matching the stator core (2) is provided inside the housing end cover (18); the fastening bolt (6) passes through the through hole (7) of the mounting flange (5) and is threadedly matched with the threaded hole (13) provided on the positioning step (12), so that the stator core (2) is fixedly mounted on the housing end cover 18; a cooling gap is formed between the outer periphery and the axial free end of the stator core (2) and the housing (19).

4. The oil-cooled motor cooling structure according to claim 3, characterized in that: An oil guide groove (14) is provided on the positioning step (12), and the oil guide groove (14) is connected to a through hole (7) connected to the drainage hole (8) and an oil outlet end of the oil inlet passage, so that cooling oil is introduced from the oil outlet end of the oil inlet passage 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 in that: The drainage holes (8) are arranged obliquely on the outer circumference of the mounting flange (5).

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

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

8. The oil-cooled motor cooling structure according to claim 1, characterized in that: The oil inlet passage comprises a connecting oil passage (15), a radial oil passage (16), and an axial oil passage (17); the oil inlet end of the connecting oil passage (15) is connected to an oil inlet port (10) provided on the outer periphery of a housing end cover (18); the oil outlet end is connected to the radial oil passage (16); the oil outlet end of the radial oil passage (16) is connected to the oil inlet end of the axial oil passage (17); the oil outlet end of the axial oil passage (17) is connected to a through hole (7) connected to the drainage hole (8).

9. The oil-cooled motor cooling structure according to claim 1, characterized in that: The stator punching sheets (4) are formed by stamping silicon steel sheets.

10. An oil-cooled motor, characterized in that: It comprises the oil-cooled motor cooling structure as described in any one of claims 1 to 9.

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