Oil-cooled hub motor

Abstract

An oil guide groove is formed on the circumference of the inner wall of an end cover of the motor, a flow channel cover plate pressed on the oil guide groove is arranged in the end cover, the flow channel cover plate and the end cover are fixedly connected, and a cooling oil flow channel is formed between the flow channel cover plate and the end cover; the sections of the cooling oil flow channels are gradually reduced from the oil inlet to the oil outlet, and the multiple cooling oil flow channels are arranged on the inner wall of the end cover in a circumferential array mode; and the oil outlet faces the stator. According to the utility model, by adopting the design of shrinking the oil guide channel, the flow speed of oil flowing out of the outlet is increased, so that the oil can be effectively sprayed to the end part of the stator winding and then diffused to the whole stator winding through capillary action, and the stator winding is fully and uniformly cooled; the problem of uneven heat dissipation of the stator winding is solved, the double-spring oil seal is adopted, the oil seal and the air contact side dustproof lip have continuous and stable holding force, and good sealing performance is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of hub motors, in particular to an oil-cooled hub motor. Background Art

[0002] Hub permanent magnet motors are widely used in the electric two-wheel vehicle market. With the improvement of the performance requirements for electric vehicles, the requirements for hub motors are becoming more and more stringent, especially in mountainous and hilly areas. The motors heat up seriously under long-term climbing conditions, and the risk of burning coils is very high. Referring to the development of new energy vehicle drive motors, the motor cooling method has gradually changed from water cooling to oil cooling, so using oil cooling to improve the heat dissipation performance of the motor is a future trend.

[0003] The existing oil-cooled motors in the two-wheeled vehicle industry are mostly directly refueled, and there are also circulating cooling oil circuits with external oil pumps. Both methods have the problem of uneven heat dissipation;

[0004] The external oil pump fixes the cooling pipe at the stator end winding and is tightly integrated with the stator through potting glue. Due to the limitations of the existing surface mount structure, the heat of the winding needs to be transferred to the cooling end through the potting glue and then taken away through the cooling oil pipe. The heat dissipation is not ideal and the cost is high.

[0005] When adding oil directly, the oil cannot reach the top winding of the stator, resulting in a large temperature difference between the winding and other parts that the oil can reach, and there is a problem of uneven heat dissipation. Although the internal plastic oil guide ring has the function of guiding oil to make the heat dissipation uniform, plastic is prone to aging in oil and high temperature environment, so special cooling oil needs to be developed, and positioning bosses need to be set for bolt locking to ensure its installation reliability, which will increase the cost accordingly. Existing two-wheeled vehicle motors mostly use a multi-lip dustproof oil seal structure, which has a poor oil sealing effect, and the motor shaft is not hard enough. As the working time of the motor increases, grooves are easily worn out at the contact between the shaft and the lip, resulting in a further decrease in the sealing effect, and there is a great risk of oil leakage and water ingress. Utility Model Content

[0006] In view of the shortcomings of the above-mentioned existing production technology, the applicant provides an oil-cooled hub motor with a reasonable structure, which has the advantages of uniform heat dissipation and good sealing effect.

[0007] The technical solution adopted by the utility model is as follows:

[0008] An oil-cooled hub motor, wherein an oil guide groove is formed circumferentially on the inner wall of the motor end cover, a flow channel cover plate pressed on the oil guide groove is arranged inside the end cover, the flow channel cover plate and the end cover are fastened and connected, and a cooling oil flow channel is formed between the two;

[0009] The cross section of the cooling oil flow channel gradually decreases from the oil inlet to the oil outlet.

[0010] A plurality of cooling oil flow channels are arranged in a circular array on the inner wall of the end cover; and the oil outlet faces the stator.

[0011] As a further improvement of the above technical solution:

[0012] The cooling oil flow channel includes an outer wall close to one side of the end cover circumference, an inner wall close to the end cover axis, and an end wall at the intersection of the outer wall and the inner wall; the axis of the oil outlet is arranged parallel to the end wall.

[0013] The flow channel cover plate is pressed on the oil guide groove of the end cover to form the inner wall of the cooling oil flow channel, and the inner wall adopts a straight wall or a curved wall;

[0014] The outer side wall adopts a curved wall;

[0015] The end wall is a straight wall.

[0016] The end wall and the outer side wall are connected by a rounded transition.

[0017] The oil outlet of the cooling oil flow channel adopts a single-hole or multi-hole oil outlet structure.

[0018] An oil seal is arranged at the center of the end cover, and the oil seal comprises a plurality of lips abutting against the motor shaft and at least two elastic members pressurized on a side of the oil seal away from the motor shaft.

[0019] The oil seal contacts the lip on the motor shaft. From the inside of the motor to the outside of the end cover, a first lip, a second lip and a third lip are sequentially arranged. A cavity is reserved between adjacent lips and filled with grease.

[0020] The top angles of the first lip and the second lip are sharp, and the top angle of the third lip is rounded;

[0021] The top angles of the first lip and the second lip form a lubricating seal.

[0022] The third lip and the motor shaft are interference fit to form a seal against the external environment.

[0023] The first lip and the second lip both include two coaxial side walls, and the inclination angles between the two coaxial side walls and the outer cylindrical surface of the motor shaft are angle α and angle β respectively, wherein angle α is close to the inside of the motor and angle α is greater than angle β.

[0024] Elastic parts are respectively arranged at the circumferential positions corresponding to the first lip and the third lip.

[0025] The beneficial effects of the utility model are as follows:

[0026] The utility model adopts a contraction oil guide channel design to increase the flow rate of the oil flowing out of the outlet, so that the oil can be effectively sprayed to the end of the stator winding, and then diffused to the entire stator winding through capillary action, so that the stator winding can be fully and evenly dissipated. The problem of uneven heat dissipation of the stator winding is overcome.

[0027] The utility model adopts a double spring oil seal, and the oil seal and the dustproof lip on the air contact side have a continuous and stable holding force, which solves the problem that the holding force of the existing hub motor oil seal and the dustproof lip on the air contact side decreases with the aging of the rubber and the motor sealing performance decreases.

[0028] During use, compared with the plastic oil guide structure, the aluminum material does not need to consider the material compatibility of the oil with the guide structure; and the all-aluminum oil guide structure can improve the thermal conductivity, and the installation is reliable and easy.

[0029] The oil of the utility model circulates in the oil channel, and less oil is accumulated at the bottom. Compared with the non-circulating flow wheel hub motor with direct oiling, the fluid resistance is smaller. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a cross-sectional view of the overall motor structure of the utility model.

[0031] Figure 2 It is an exploded view of the end cover and flow channel cover plate of the utility model.

[0032] Figure 3 It is a three-dimensional diagram of the end cover of the utility model.

[0033] Figure 4 This is a stereoscopic view of the end cover of the utility model from another perspective.

[0034] Figure 5 for Figure 4 The enlarged view of part B is used to illustrate the oil guide groove structure.

[0035] Figure 6 It is the front view of the motor of the present utility model.

[0036] Figure 7 for Figure 6 The AA cross-sectional view is used to reflect the cross-sectional changes of the cooling oil flow channel.

[0037] Figure 8 It is a schematic diagram of the installation of the oil seal structure of the utility model.

[0038] Fig. 9 for Figure 8 The enlarged view of part C is used to illustrate the oil seal structure.

[0039] Fig.10 It is a schematic diagram of the angle setting of the first lip and the second lip of the utility model.

[0040] Fig.11 This is a front view of the motor of the present utility model, and the partial section in the figure is used to reflect the position and structure of a single cooling oil flow channel.

[0041] Among them: 1. End cover; 2. Flow channel cover plate; 3. Cooling oil flow channel; 4. Oil seal; 5. Elastic part; 6. Grease; 7. Bolts; 8. Motor shaft;

[0042] 101, oil guide groove;

[0043] 301, oil inlet; 302, oil outlet; 303, outer wall; 304, inner wall; 305, end wall;

[0044] 401, first lip; 402, second lip; 403, third lip. DETAILED DESCRIPTION

[0045] The specific implementation of the present utility model is described below in conjunction with the accompanying drawings.

[0046] like Figure 1-Figure 11 As shown, in the oil-cooled hub motor of this embodiment, an oil guide groove 101 is formed circumferentially on the inner wall of the end cover 1 of the motor, a flow channel cover plate 2 pressed on the oil guide groove 101 is arranged inside the end cover 1, and the flow channel cover plate 2 and the end cover 1 are fastened to form a cooling oil flow channel 3 between the two;

[0047] The cross section of the cooling oil flow channel 3 gradually decreases from the oil inlet 301 to the oil outlet 302.

[0048] A plurality of cooling oil channels 3 are provided in a circular array on the inner wall of the end cover 1 ; and the oil outlet 302 faces the stator.

[0049] The cooling oil flow channel 3 includes an outer wall 303 close to one side of the circumference of the end cover 1 , an inner wall 304 close to the axis of the end cover 1 , and an end wall 305 where the outer wall 303 and the inner wall 304 intersect; the axis of the oil outlet 302 is arranged parallel to the end wall 305 .

[0050] The flow channel cover plate 2 is pressed on the oil guide groove 101 of the end cover 1 to form the inner wall 304 of the cooling oil flow channel 3. The inner wall 304 is a straight wall or a curved wall.

[0051] The outer side wall 303 is a curved wall;

[0052] The end wall 305 is a straight wall.

[0053] The end wall 305 and the outer side wall 303 are connected by a rounded transition.

[0054] The oil outlet 302 of the cooling oil flow channel 3 adopts a single-hole or multi-hole oil outlet structure.

[0055] An oil seal 4 is arranged at the center of the end cover 1 . The oil seal 4 includes a plurality of lips abutting against the motor shaft 8 and at least two elastic members 5 pressurized on a side of the oil seal 4 away from the motor shaft 8 .

[0056] The oil seal 4 contacts the lip on the motor shaft 8 , and a first lip 401 , a second lip 402 , and a third lip 403 are sequentially provided from the inside of the motor to the outside of the end cover 1 , and a cavity is reserved between adjacent lips, and the cavity is filled with grease 6 .

[0057] The top angles of the first lip 401 and the second lip 402 are sharp, and the top angle of the third lip 403 is rounded;

[0058] The top corners of the first lip 401 and the second lip 402 form a lubricating seal.

[0059] The third lip 403 and the motor shaft 8 are interference-fitted to form a seal against the external environment.

[0060] The first lip 401 and the second lip 402 each include two coaxial side walls, and the inclination angles between the two coaxial side walls and the outer circumferential surface of the motor shaft 8 are angles α and β respectively, wherein angle α is close to the inside of the motor and angle α is greater than angle β.

[0061] Elastic members 5 are respectively provided at circumferential positions corresponding to the first lip 401 and the third lip 403 .

[0062] The specific structure and working principle of the utility model are as follows:

[0063] like Figure 1 and Figure 2 As shown, the end cover 1 and the flow channel cover plate 2 of the motor form a cooling oil flow channel 3 that allows oil to pass through, and bolts 7 connect the end cover 1 and the flow channel cover plate 2 to fix the relative position between the two.

[0064] like Figure 4 and Figure 6 , Figure 7 As shown, the cross-sectional area of ​​the cooling oil flow channel 3 gradually decreases from the oil inlet 301, and the oil outlet 302 of the cooling oil flow channel 3 is the smallest cross-sectional area of ​​the entire flow channel. When the cooling oil flows through the cooling oil flow channel 3 with a gradually decreasing cross-sectional area, the flow velocity gradually increases, and the cooling oil is accelerated and pressurized and sprayed onto the stator from the oil outlet 302, thereby achieving the effect of cooling the stator.

[0065] In the utility model, after the flow channel cover plate 2 and the end cover 1 are matched, the flow channel cover plate 2 serves as the inner side wall 304 of the cooling oil flow channel 3. A cooling oil flow channel 3 includes an outer side wall 303 provided by the end cover 1, an inner side wall 304 served by the flow channel cover plate 2, and an end wall 305 of the outer side wall 303 close to the oil outlet 302. The end wall 305 and the outer side wall 303 are connected by a rounded transition, forming an acceleration pressurization channel with a large oil inlet 301 and a small oil outlet 302.

[0066] The side wall and end wall 305 of the cooling oil flow channel 3 can be designed in the form of a straight wall or a curved wall. Considering the ease of manufacturing the flow channel cover plate 2, the inner side wall 304 is preferably a straight wall; considering the flow of the oil, the outer side wall 303 is preferably a curved wall arranged along a spiral line; considering the smooth flow of the oil, the end wall 305 is a straight wall and is connected to the outer side wall 303 with a rounded transition.

[0067] The cross-section of the oil outlet 302 can be polygonal, circular, or adopt a multi-hole oil outlet method. In one embodiment of the utility model, the oil outlet 302 adopts a structure with a parallelogram cross-section, and at least one edge of the oil outlet 302 is parallel to the end wall 305, ensuring that the oil is effectively sprayed on the stator coil.

[0068] As an alternative embodiment,

[0069] In consideration of the smooth flow of oil, the outer wall 303 and the inner wall 304 may both be arcuate walls, and the end wall 305 may be a straight wall.

[0070] With the oil cooling structure of the utility model, the cooling oil circulates in the cooling oil flow channel 3 formed by the end cover 1, the bolts 7 and the flow channel cover plate 2. The oil at the bottom of the motor is less than that of a conventional motor, thereby effectively reducing the oil resistance.

[0071] Under the premise of oil circulation injection, the utility model further arranges an oil seal 4 to achieve sealing of oil and grease.

[0072] like Figure 8 and Fig. 9 As shown, the oil seal 4 is sleeved between the motor shaft 8 and the end cover 1, and the inner wall of each oil seal 4 that contacts the motor shaft 8 is sequentially provided with a first lip 401, a second lip 402 and a third lip 403. Two depressions are provided on the outer wall of the oil seal 4, and two springs are pressurized to continuously apply a clamping force. The two springs correspond to the positions of the first lip 401 and the third lip 403, respectively, to solve the problem that the rubber of the lip of the oil seal 4 on the side in contact with the air of the existing hub motor 4 gradually ages over time, resulting in a decrease in the clamping force, and to improve the sealing performance of the motor.

[0073] The first lip 401 and the second lip 402 are pointed in shape, and the third lip 403 is rounded in shape. A cavity is provided between the first lip 401 and the second lip 402 and between the second lip 402 and the third lip 403, and the cavity is filled with lubricating grease 6.

[0074] The third lip 403 is interference fit with the motor shaft 8 to prevent the entry of foreign matter such as water and dust from the outside, and to prevent the grease 6 from leaking out;

[0075] according to Fig. 9 and Fig.10In the middle position, the angles of the first lip 401 and the second lip 402 are set to be the same, and one of them is used as an example for explanation. The left angle α of the first lip 401 is greater than the right angle β, which can prevent the grease 6 between the first lip 401 and the second lip 402 from leaking out; and the grease 6 filled in the cavity between the second lip 402 and the third lip 403 can be pumped into the cavity between the first lip 401 and the second lip 402, ensuring that the grease 6 carried away by the oil at the contact point between the first lip 401 and the motor shaft 8 can be replenished and well lubricated.

[0076] The above description is an explanation of the utility model, not a limitation of the utility model. The scope of the utility model is defined by the claims. Any form of modification can be made within the protection scope of the utility model.

Claims

1. An oil-cooled hub motor, characterized in that: An oil guide groove (101) is formed circumferentially on the inner wall of the end cover (1) of the motor, a flow channel cover plate (2) pressed on the oil guide groove (101) is arranged inside the end cover (1), the flow channel cover plate (2) and the end cover (1) are tightly connected, and a cooling oil flow channel (3) is formed between the two. The cross section of the cooling oil flow channel (3) gradually decreases from the oil inlet (301) to the oil outlet (302). A plurality of cooling oil flow channels (3) are provided in a circular array on the inner wall of the end cover (1); and the oil outlet (302) faces the stator.

2. The oil-cooled hub motor according to claim 1, characterized in that: The cooling oil flow channel (3) comprises an outer wall (303) close to one side of the circumference of the end cover (1), an inner wall (304) close to the axis of the end cover (1), and an end wall (305) at the intersection of the outer wall (303) and the inner wall (304); the axis of the oil outlet (302) is arranged parallel to the end wall (305).

3. The oil-cooled hub motor according to claim 2, characterized in that: The flow channel cover plate (2) is pressed onto the oil guide groove (101) of the end cover (1) to form an inner wall (304) of the cooling oil flow channel (3), and the inner wall (304) is a straight wall or a curved wall; The outer side wall (303) is a curved wall; The end wall (305) is a straight wall.

4. The oil-cooled hub motor according to claim 3, characterized in that: The end wall (305) and the outer side wall (303) are connected by a rounded transition.

5. The oil-cooled hub motor according to claim 2, characterized in that: The oil outlet (302) of the cooling oil flow channel (3) adopts a single-hole or multi-hole oil outlet structure.

6. The oil-cooled hub motor according to claim 1, characterized in that: An oil seal (4) is arranged at the center of the end cover (1), and the oil seal (4) comprises a plurality of lips that abut against the motor shaft (8) and at least two elastic members (5) that are pressurized on a side of the oil seal (4) that faces away from the motor shaft (8).

7. The oil-cooled hub motor according to claim 6, characterized in that: The oil seal (4) contacts the lip on the motor shaft (8), and a first lip (401), a second lip (402), and a third lip (403) are sequentially arranged from the inside of the motor to the outside of the end cover (1), and a cavity is reserved between adjacent lips, and the cavity is filled with grease (6).

8. The oil-cooled hub motor according to claim 7, characterized in that: The top angles of the first lip (401) and the second lip (402) are sharp angles, and the top angle of the third lip (403) is rounded; The top angles of the first lip (401) and the second lip (402) form a lubricating seal. The third lip (403) and the motor shaft (8) are interference-fitted to form a seal against the external environment.

9. The oil-cooled hub motor according to claim 8, characterized in that: The first lip (401) and the second lip (402) both include two coaxial side walls, and the inclination angles between the two coaxial side walls and the outer circular surface of the motor shaft (8) are angles α and β respectively, wherein angle α is close to the inside of the motor and angle α is greater than angle β.

10. The oil-cooled hub motor according to claim 7, characterized in that: Elastic parts (5) are respectively arranged at circumferential positions corresponding to the first lip (401) and the third lip (403).

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