Cooling and lubricating system for an electric drive assembly

Abstract

The utility model discloses a cooling lubrication system of electric drive assembly, including speed reducer, motor, half axle subassembly and oil cooling circulation system, oil cooling circulation system includes oil storage cavity, oil pump, oil cooler, speed reducer oil cooling system and motor oil cooling system, oil storage cavity is connected with oil cooler through conveying oil circuit, and oil pump sets up on conveying oil circuit, and the oil inlet of speed reducer oil cooling system is connected with conveying oil circuit, and the oil outlet of speed reducer oil cooling system is connected with oil storage cavity, the oil inlet of motor oil cooling system is connected with oil cooler, and the oil outlet of motor oil cooling system is connected with oil storage cavity, be provided with coarse filter and fine filter on conveying oil circuit, and the coarse filter is located the upstream side of oil pump, and the fine filter is located the downstream side of oil pump, the utility model discloses coarse filter and fine filter can filter treatment to oil liquid, avoid internal impurity and block the oil way, guarantee the cleanliness of electric drive inside, improve the oil cooling effect.

Description

Technical Field

[0001] This utility model relates to the field of new energy vehicle technology, specifically to a cooling and lubrication system for an electric drive assembly. Background Technology

[0002] The electric drive system is the core power unit of new energy vehicles, including key components such as motors, reducers, and controllers, responsible for converting electrical energy into mechanical energy to drive the vehicle. Under prolonged high-load conditions, internal components of the electric drive system, such as bearings and rotors, are prone to high heat and wear, thus requiring an efficient cooling and lubrication mechanism to ensure system stability and service life.

[0003] The internal cleanliness of the cooling and lubrication system of existing electric drive assemblies cannot be controlled, which can easily lead to the generation of impurities inside and affect the service life of the electric drive. Utility Model Content

[0004] In view of this, the present invention provides a cooling and lubrication system for an electric drive assembly to solve the problem that easily worn parts such as the gear shaft of the reducer in the current cooling and lubrication system of the electric drive assembly cannot be given priority lubrication.

[0005] This utility model provides a cooling and lubrication system for an electric drive assembly, including a reducer, a motor, a half-shaft assembly, and an oil cooling circulation system. The reducer includes a reducer housing and a reducer gear shaft. The oil cooling circulation system includes an oil storage chamber, an oil pump, an oil cooler, a reducer oil cooling system, and a motor oil cooling system; The oil storage chamber is connected to the oil cooler via an oil delivery circuit; The oil pump is installed on the oil delivery line and is used to drive the cooling oil to flow in the oil cooling circulation system; The oil cooler is used to cool the cooling oil entering the motor oil cooling system; The oil inlet of the reducer oil cooling system is connected to the oil delivery circuit, and the oil outlet of the reducer oil cooling system is connected to the oil storage chamber. The reducer oil cooling system is used to introduce cooling oil into the reducer to lubricate and cool the internal structure and gear shaft of the reducer. The oil storage chamber, the oil delivery circuit, the oil pump and the reducer oil cooling system constitute the reducer circulation oil circuit. The oil inlet of the motor oil cooling system is connected to the oil cooler, and the oil outlet of the motor oil cooling system is connected to the oil storage chamber. The motor oil cooling system is used to introduce cooling oil into the motor for lubrication and cooling. The oil storage chamber, the oil delivery circuit, the oil pump, the oil cooler, and the motor oil cooling system together form the motor circulation oil circuit. The oil delivery line is equipped with a coarse filter and a fine filter. The coarse filter is located upstream of the oil pump, and the fine filter is located downstream of the oil pump.

[0006] The beneficial effects of the above technical solution are as follows: the oil cooling system can accurately distribute the oil volume of each cooling circulation branch, ensuring that the internal heat-generating components are adequately lubricated, improving the cooling efficiency of the electric drive assembly, and thus allowing the motor performance to be fully utilized. The coarse and fine filters can filter the oil, preventing internal impurities from clogging the oil passages, ensuring the cleanliness of the electric drive interior, and improving the oil cooling effect.

[0007] The coarse filter pre-filters large particles of impurities in the oil, preventing them from entering the oil pump and causing internal wear or jamming. The fine filter, located downstream, further filters out tiny particles, ensuring the cleanliness of the oil entering the reducer and motor oil passages and preventing blockage of precision components. Clean oil keeps the oil passages clear, preventing uneven flow distribution caused by impurity buildup, ensuring precise oil supply to each lubrication point in the reducer and motor, stable cooling efficiency, and guaranteeing continuous and reliable operation of the electric drive assembly under high load conditions.

[0008] In one optional embodiment, the oil delivery circuit between the fine filter and the oil cooler is connected to the oil inlet of the reducer's oil cooling system.

[0009] In one alternative embodiment, the motor includes a front bearing, a rear bearing, a bearing plate, a stator assembly, a rotor assembly, an end cover, a cover plate, an eddy current sensor, an oil seal, and a sealing ring. The stator assembly includes a housing and a stator component, the stator component includes a stator and windings, and the oil reservoir is located at the bottom of the housing; The rotor assembly is rotatably mounted inside the housing at both ends via a front bearing and a rear bearing. The rotor assembly includes a shaft and a rotor. The shaft has a hollow interior to allow the half-shaft assembly to pass through. The end cap is connected to the end of the housing; The cover plate is used to encapsulate the end cap and the housing; The oil seal and sealing ring are installed inside the cover plate.

[0010] In one alternative embodiment, the housing is provided with carbon fiber brushes; and / or, the rear bearing is a ceramic ball bearing, which can effectively suppress the occurrence of electro-corrosion.

[0011] In one optional embodiment, the motor oil cooling system includes a stator oil cooling circuit, which includes a stator oil inlet, a stator annular oil groove, an internal stator oil passage, and a stator oil spray hole. The stator oil inlet is located on the housing, the stator annular oil groove is arranged around the outer periphery of the stator, the stator annular oil groove is connected to the stator oil spray hole through the internal stator oil passage, and the stator oil spray hole leads to the end of the winding. The oil output from the end of the winding flows into the oil storage chamber.

[0012] The beneficial effects of the above technical solution are as follows: By arranging the stator annular oil grooves around the outer circumference of the stator, the cooling oil can be evenly distributed to various areas of the stator along the annular path, and then guided to different positions through the internal oil channels of the stator, ensuring uniform temperature distribution of the stator core and windings as a whole, and avoiding the insulation aging problem caused by local heat accumulation in traditional cooling methods. The stator oil spray holes are directly connected to the winding ends, directing the cooling oil to the winding end areas of the motor that are most prone to heat generation. The direct contact of the oil with the winding ends removes heat, reducing the temperature of the winding ends and significantly improving the motor's overload resistance and continuous operating stability. After cooling the winding ends, the cooling oil can flow directly back to the oil storage chamber, forming a closed-loop path of oil inlet-cooling-return.

[0013] In one optional embodiment, the motor oil cooling system further includes a rotor oil cooling circuit, which includes a housing rotor oil inlet, an end cover oil circuit, a cover plate oil circuit, a half-shaft assembly oil circuit, and a motor shaft oil circuit. The housing rotor oil inlet is located on the housing and is connected to the cover plate oil circuit through the end cover oil circuit. The cover plate oil circuit is divided into a first oil circuit connected to the half-shaft assembly oil circuit and a second oil circuit connected to the motor shaft oil circuit.

[0014] In one optional embodiment, the end cap oil circuit includes an end cap oil inlet, an end cap oil outlet, and an end cap drain hole disposed on the end cap, wherein the end cap oil inlet and the end cap oil outlet are connected. The cover plate oil circuit includes a first oil hole, a second oil hole, and a third oil hole on the cover plate. The end cap oil outlet is connected to the first oil hole. The second and third oil holes are respectively connected to both sides of the first oil hole. The second oil hole is connected to the half-shaft assembly oil circuit, and the third oil hole is connected to the motor shaft oil circuit.

[0015] In one alternative embodiment, the half-shaft assembly includes a small half-shaft and a half-shaft bearing, wherein the small half-shaft is provided with a half-shaft spline inside. The oil passage of the half-shaft assembly includes an inclined oil groove and an oil slinger hole. The inclined oil groove extends axially on the small half-shaft, and the oil slinger hole extends radially through the small half-shaft. The inclined oil groove communicates with the spline surface of the half-shaft, and the oil slinger hole is used to guide the cooling oil to the half-shaft bearing and oil seal.

[0016] The beneficial effects of the above technical solution are as follows: the rotor oil cooling circuit is divided into two independent branches—the half-shaft assembly and the motor shaft—through the cover plate oil circuit, which can simultaneously achieve precise lubrication of the small half-shaft splines, half-shaft bearings, front and rear motor bearings, and rotor core. The internal oil seals / bearings of the half-shaft assembly are directly lubricated, and the internal splines of the half-shaft can also be lubricated, ensuring consistency between the interfaces on the motor side and the differential side. The entire vehicle's half-shaft splines are adequately lubricated, which is beneficial for the overall vehicle structural layout.

[0017] In one optional embodiment, the motor shaft oil passage includes a first oil hole, a second oil hole, a third oil hole, and a fourth oil hole distributed along the shaft axis. The first oil hole is used to guide oil to the rear bearing of the motor, the second and third oil holes are used to guide oil to the rotor, and the fourth oil hole is used to guide oil to the front bearing.

[0018] In one optional embodiment, a controller is also provided outside the reducer and the motor, and the cooling and lubrication system further includes a water-cooled circulation system for cooling the controller, the water-cooled circulation system including circulating water paths connected to the controller and the oil cooler respectively. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the assembly structure of a cooling and lubrication system for an electric drive assembly provided by this utility model; Figure 2 A cross-sectional view of the cooling and lubrication system of an electric drive assembly provided by this utility model; Figure 3 A schematic diagram of the stator assembly of a cooling and lubrication system for an electric drive assembly provided by this utility model; Figure 4 A schematic diagram of the stator assembly of a cooling and lubrication system for an electric drive assembly provided by this utility model; Figure 5 A schematic diagram of the end cover of a cooling and lubrication system for an electric drive assembly provided by this utility model; Figure 6 A schematic diagram of a cover plate for a cooling and lubrication system of an electric drive assembly provided by this utility model; Figure 7 A schematic diagram of the rotor assembly of a cooling and lubrication system for an electric drive assembly provided by this utility model; Figure 8 A schematic diagram of the small half-shaft of a cooling and lubrication system for an electric drive assembly provided by this utility model; Figure 9 A schematic diagram of a cooling and lubrication system for an electric drive assembly provided by this utility model; Figure 10 A schematic diagram of the stator cooling route of a cooling and lubrication system for an electric drive assembly provided by this utility model; Figure 11 A schematic diagram of the rotor cooling route of the cooling and lubrication system of an electric drive assembly provided by this utility model. Figure 12 A schematic diagram of the water cooling route for a cooling and lubrication system of an electric drive assembly provided by this utility model.

[0021] Explanation of reference numerals in the attached figures: 1. Reducer; 11. Reducer housing; 12. Reducer gear shaft; 2. Controller; 3. Motor; 31. Front bearing; 32. Bearing pressure plate; 33. Carbon fiber brush; 34. Rotor assembly; 341. Shaft; 3411. First oil hole; 3412. Second oil hole; 3413. Third oil hole; 3414. Fourth oil hole; 342. Rotor; 35. Stator assembly; 351. Housing; 3511. Fine filter oil inlet; 3512. Fine filter oil outlet; 3513. Oil cooler oil inlet; 3514. Oil cooler water inlet; 3515. Control... 3516. Rotor oil inlet; 3517. Oil cooler oil outlet; 3518. Stator oil inlet; 3519. Oil pump mounting hole; 352. Stator assembly; 3521. Stator annular oil groove; 3522. Stator internal oil passage; 3523. Stator oil injection hole; 36. Rear bearing; 37. Eddy current sensor; 38. Cover plate; 381. First oil hole of cover plate; 382. Second oil hole of cover plate; 383. Third oil hole of cover plate; 39. Oil seal. 4. Fine filter; 40. End cap; 401. End cap oil inlet; 402. End cap oil outlet; 403. End cap oil drain hole; 41. Sealing ring; 42. Oil storage chamber; 5. Oil pump; 6. Oil cooler; 7. Half-shaft assembly; 71. Small half-shaft; 711. Oil slinger hole; 712. Inclined oil groove; 713. End groove; 8. Coarse filter. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0023] Combination Figures 1 to 12As shown below, the embodiments of this utility model are described in detail with reference to the cooling and lubrication system of this utility model.

[0024] According to an embodiment of this utility model, a cooling and lubrication system for an electric drive assembly is provided, specifically a cooling and lubrication system for an asynchronous coaxial electric drive assembly, including a reducer 1, a motor 3, a half-shaft assembly 7, and an oil cooling circulation system. The cooling and lubrication system is used to cool the internal components of the electric drive assembly and operates in a reciprocating cycle within the system. The oil cooling system can precisely distribute the oil volume in each cooling circulation branch, ensuring sufficient lubrication of internal heat-generating components, improving the cooling efficiency of the electric drive assembly, and thus fully utilizing the motor performance.

[0025] The oil cooling circulation system includes an oil storage chamber 42, an oil pump 5, an oil cooler 6, a reducer oil cooling system, and a motor oil cooling system. The oil pump 5 and the oil cooler 6 are installed on the motor 3.

[0026] The oil storage chamber 42 is connected to the oil cooler 6 through an oil delivery circuit, and the oil storage chamber 42 is located inside the electric drive oil pan.

[0027] Oil pump 5 is installed on the oil delivery line to drive the cooling oil to flow in the oil cooling circulation system.

[0028] Oil cooler 6 is used to cool the cooling oil entering the motor oil cooling system.

[0029] The reducer 1 includes a reducer housing 11 and a reducer gear shaft 12. The oil inlet of the reducer oil cooling system is connected to the oil delivery circuit, and its oil outlet is connected to the oil storage chamber 42. The reducer oil cooling system is used to introduce cooling oil into the reducer 1 to lubricate and cool the internal structure of the reducer and the reducer gear shaft 12. The oil storage chamber 42, the oil delivery circuit, the oil pump 5, and the reducer oil cooling system constitute the reducer circulating oil circuit.

[0030] The oil inlet of the motor oil cooling system is connected to the oil cooler 6, and its outlet is connected to the oil storage chamber 42. The motor oil cooling system is used to introduce cooling oil into the motor 3 for lubrication and cooling. The oil storage chamber 42, the oil delivery circuit, the oil pump 5, the oil cooler 6, and the motor oil cooling system together form the motor circulating oil circuit.

[0031] A coarse filter 8 and a fine filter 4 are installed on the oil delivery line. The coarse filter 8 is located upstream of the oil pump 5, and the fine filter 4 is located downstream of the oil pump 5. The coarse filter 8 and the fine filter 4 are respectively installed on the motor 3. The coarse filter 8 can pre-filter large particulate impurities in the oil to prevent impurities from entering the oil pump and causing internal wear or jamming. The fine filter 4, located downstream, further filters fine particles to ensure the cleanliness of the oil entering the reducer and motor oil passages, preventing blockage of precision components. Clean oil can keep the oil passages unobstructed, avoid uneven flow distribution caused by impurity accumulation, ensure accurate oil supply to each lubrication point of the reducer and motor, maintain stable cooling efficiency, and ensure continuous and reliable operation of the electric drive assembly under high load conditions.

[0032] Preferably, the oil supply line between the fine filter 4 and the oil cooler 6 is connected to the oil inlet of the reducer's oil cooling system, so that the finely filtered oil can be input into the reducer and the reducer gear shaft.

[0033] The cooling and lubrication requirements of the reducer prioritize lubrication and are mainly supplemented by cooling. Its circulating oil circuit (oil reservoir → oil pump → reducer oil cooling system → oil reservoir) does not pass through the oil cooler. It uses the fluidity of the oil itself to carry away the frictional heat of the reducer gear shaft and bearings, which satisfies the lubrication requirements and avoids unnecessary energy consumption.

[0034] The motor is a high-heat-generating component (stator winding, rotor core), which requires enhanced cooling with low-temperature oil. Its circulating oil circuit (oil reservoir → oil pump → oil cooler → motor oil cooling system → oil reservoir) is cooled by the oil cooler and then the low-temperature oil is delivered to the inside of the motor, which specifically solves the problem of overheating of the motor under long-term high load.

[0035] The working process of the oil cooling circulation system is as follows: S1. Oil extraction and preliminary filtration: The cooling oil in the oil storage chamber 42 is drawn into the oil pump 5 through the oil delivery circuit. First, it passes through the coarse filter 8 to filter out large particles of impurities, so as to prevent impurities from entering the oil pump and causing wear.

[0036] S2. Pressurization and fine filtration: After the oil pump 5 pressurizes the oil, the oil enters the fine filter 4) for secondary filtration to remove tiny impurities and ensure the cleanliness of the oil entering the cooling oil circuit.

[0037] S3. Reducer oil cooling path: Part of the filtered oil directly enters the reducer oil cooling system, passes through the oil passage inside the reducer housing 11 and lubricates the reducer gear shaft 12 and other transmission components, and after absorbing heat, it flows back to the oil storage chamber 42.

[0038] S4. Motor oil cooling path: Another part of the oil first enters the oil cooler 6 to cool down, and then enters the motor oil cooling system to lubricate and cool the stator windings, rotor bearings and other components, and finally flows back to the oil storage chamber 42.

[0039] S5. Oil pump 5 continuously drives the oil to circulate within the system, achieving continuous lubrication and cooling of the reducer and motor.

[0040] The aforementioned oil cooling circulation system, through dual-path independent oil supply, can distribute the oil volume according to the heating characteristics of the reducer and motor, ensuring sufficient lubrication of each component; the forced cooling of the oil cooler 6 reduces the temperature of the motor oil, significantly improving the motor's heat dissipation efficiency and avoiding performance degradation caused by overheating.

[0041] The oil cooling system is integrated into the motor housing, eliminating the need for additional large pipelines and reducing space occupation; the oil pump is an electronic oil pump that adjusts the flow rate as needed, adapting to the energy-saving requirements of new energy vehicles.

[0042] In some embodiments, the motor 3 includes a front bearing 31, a rear bearing 36, a bearing pressure plate 32, a stator assembly 35, a rotor assembly 34, an end cover 40, a cover plate 38, a carbon fiber brush 33, an eddy current sensor 37, an oil seal 39, and a sealing ring 41. The stator assembly 35 includes a housing 351 and a stator assembly 352, which includes a stator and windings. An oil reservoir 42 is disposed at the bottom of the housing 351. The two ends of the rotor assembly 34 are rotatably disposed inside the housing 351 via the front bearing 31 and the rear bearing 36. The rotor assembly 34 includes a shaft 341 and a rotor 342. The shaft 341 is hollow to allow the half-shaft assembly 7 to pass through. The end cover 40 is connected to the end of the housing 351. The cover plate 38 is used to encapsulate the end cover 40 and the housing 351. The carbon fiber brush 33 is installed inside the housing 351, the rear bearing 36 and the eddy current sensor 37 are installed inside the end cover 40; the oil seal 39 and the sealing ring 41 are installed inside the cover plate 38.

[0043] The housing 351 is equipped with the following main parts: fine filter oil inlet 3511, fine filter oil outlet 3512, oil cooler oil inlet 3513, oil cooler water inlet 3514, controller water outlet 3515, rotor oil inlet 3516, oil cooler oil outlet 3517, stator oil inlet 3518, and oil pump mounting hole 3519.

[0044] The housing 351 has a carbon fiber brush 33 inside, and the rear bearing 36 is a ceramic ball bearing, which can effectively suppress the occurrence of electro-corrosion.

[0045] In some embodiments, the reducer housing 11 is integrally integrated with the motor housing 351, and the reducer gear shaft 12 is disposed inside the reducer housing 11. After being adsorbed by the negative pressure of the oil pump 5, the cooling oil is drawn into the oil pump from the coarse filter 8, and then sent to the fine filter 4 for filtration before entering the delivery oil circuit. Part of the cooling oil enters the reducer 1 and the reducer gear shaft 12 for lubrication, of which a small portion of the oil is used for cooling and lubricating the reducer gear shaft 12, and the other portion enters the motor 3 for cooling through the oil cooler 6.

[0046] In some embodiments, the motor oil cooling system includes a stator oil cooling circuit, which includes a stator oil inlet 3518, a stator annular oil groove 3521, a stator internal oil passage 3522, and a stator oil spray hole 3523. The stator oil inlet 3518 is disposed on the housing 351. The stator annular oil groove 3521 is arranged around the outer periphery of the stator. The stator annular oil groove 3521 is connected to the stator oil spray hole 3523 through the stator internal oil passage 3522. The stator oil spray hole 3523 leads to the end of the winding, and the end of the winding is connected to the oil storage chamber 42.

[0047] In this embodiment, the stator annular oil groove 3521 is arranged around the outer periphery of the stator, allowing the cooling oil to be evenly distributed to various areas of the stator along the annular path. The oil is then guided to different locations via the internal oil channels 3522, ensuring a uniform temperature distribution across the stator core and windings, thus avoiding insulation aging problems caused by localized heat accumulation in traditional cooling methods. The stator oil spray holes 3523 directly connect to the winding ends, directing the cooling oil to the most heat-prone winding end areas of the motor. Direct contact with the oil removes heat, lowering the winding end temperature and significantly improving the motor's overload resistance and continuous operational stability. After cooling the winding ends, the cooling oil can flow directly back to the oil reservoir 42, forming a closed-loop path of oil inlet-cooling-return. The stator oil cooling circuit's oil channels (annular oil groove, internal oil channels) are integrated within the housing 351 and stator assembly 352, eliminating the need for additional external piping, reducing space occupation, and further improving the integration level of the electric drive assembly.

[0048] In some embodiments, the motor oil cooling system further includes a rotor oil cooling circuit, which includes a housing rotor oil inlet 3516, an end cover oil circuit, a cover plate oil circuit, a half-shaft assembly oil circuit, and a motor shaft oil circuit. The housing rotor oil inlet 3516 is located on the housing 351 and is connected to the cover plate oil circuit via the end cover oil circuit. The cover plate oil circuit is divided into a first oil circuit connected to the half-shaft assembly oil circuit and a second oil circuit connected to the motor shaft oil circuit. The lubricating oil from the stator oil cooling circuit and the rotor oil cooling circuit finally enters the oil storage chamber 42 and then passes through the oil cooling system for reuse, thus forming the entire circulating oil circuit.

[0049] The end cap 40 is provided with an oil inlet 401, an oil outlet 402, and an oil drain 403. The oil inlet 401 and the oil outlet 402 are connected.

[0050] The cover plate 38 is provided with a first oil hole 381, a second oil hole 382, ​​and a third oil hole 383. The end cover oil outlet 402 is connected to the first oil hole 381. The second oil hole 382 and the third oil hole 383 are respectively connected to both sides of the first oil hole 381. The second oil hole 382 is connected to the oil circuit of the half shaft assembly, and the third oil hole 383 is connected to the oil circuit of the motor shaft.

[0051] The half-shaft assembly 7 includes a small half-shaft 71 and a half-shaft bearing 72, and the small half-shaft 71 is provided with a half-shaft spline inside.

[0052] The oil passage of the half-shaft assembly includes an inclined oil groove 712 and an oil sling hole 711. The inclined oil groove 712 extends axially and is disposed on the small half-shaft 71. The oil sling hole 711 is disposed radially through the small half-shaft 71. The inclined oil groove 712 communicates with the spline surface of the half-shaft. The oil sling hole 711 is used to guide the cooling oil to the half-shaft bearing 72 and the oil seal 39.

[0053] The motor shaft oil passage includes a first oil hole 3411, a second oil hole 3412, a third oil hole 3413 and a fourth oil hole 3414 distributed along the axial direction of the shaft 341. The first oil hole 3411 is used to pass oil to the rear bearing 36 of the motor, the second oil hole 3412 and the third oil hole 3413 are used to pass oil to the rotor 342, and the fourth oil hole 3414 is used to pass oil to the front bearing 31.

[0054] The specific cooling oil transmission path of the aforementioned rotor oil cooling circuit is as follows: Cooling oil enters from the rotor inlet 3516 in the housing, passes through the end cover inlet 401 and the end cover outlet 402, and enters the first oil hole 381 in the cover plate. A portion of the cooling oil enters the half-shaft assembly 7 from the second oil hole 382 in the cover plate, lubricating the half-shaft bearing 72 and oil seal 39; subsequently, the cooling oil lubricates the small half-shaft spline through the end groove 713 and the inclined oil groove 712, and finally exits through the small half-shaft oil ejector hole 711. Another portion of the cooling oil enters the motor shaft 341 from the third oil hole 383 in the cover plate, lubricating the rear bearing 36 of the motor through the first oil hole 3411 on the shaft 341, cooling the cast aluminum rotor through the second oil hole 3412 on the shaft 341, cooling the cast aluminum rotor through the third oil hole 3413 on the shaft 341, and lubricating the front bearing 31 of the motor through the fourth oil hole 3414 on the shaft 341.

[0055] In this embodiment, the rotor oil cooling circuit is divided into two independent branches—one for the half-shaft assembly and the other for the motor shaft—through a cover plate. This allows for precise lubrication of the small half-shaft splines, half-shaft bearings, front and rear motor bearings, and the rotor core simultaneously. For example, the inclined oil groove 712 directly lubricates the half-shaft spline surface, while the oil slinger hole 711 provides directional lubrication to the half-shaft bearing 72. The first / fourth oil holes in the shaft oil circuit lubricate the rear bearing 36 and the front bearing 31, respectively, while the second / third oil hole cools the cast aluminum rotor, achieving full-area lubrication coverage from bearings to splines to the rotor. The internal oil seals / bearings of the half-shaft assembly are directly lubricated, and the internal splines of the half-shaft are also lubricated, ensuring consistency between the interfaces on the motor side and the differential side. This provides sufficient lubrication for the entire vehicle's half-shaft splines, which is beneficial for the overall vehicle structural layout.

[0056] Cooling oil enters the rotor core area directly through the oil holes inside the shaft, carrying away the heat lost due to eddy currents generated by the high-speed rotation of the motor, thus reducing the rotor temperature and increasing the continuous output power of the motor, which is suitable for the high torque requirements of new energy vehicles.

[0057] The design of the inclined oil groove 712 and oil sling hole 711 of the small half shaft 71 ensures that the spline of the half shaft is fully lubricated when transmitting torque, reducing spline wear and abnormal noise. At the same time, it makes the interface on the motor side and the differential side consistent, which facilitates the unified and standardized design of the half shaft of the whole vehicle and reduces the assembly difficulty.

[0058] The oil passages of the rotor oil cooling circuit (end cover oil passage, cover plate oil passage, and shaft oil passage) are all integrated into the internal structure of the motor (end cover 40, cover plate 38, and shaft 341), eliminating the need for external pipeline connections, reducing the risk of leakage, and shortening the oil flow path.

[0059] In some embodiments, a controller 2 is also provided externally to the reducer 1 and the motor 3. The cooling and lubrication system further includes a water-cooled circulation system for cooling the controller 2. The water-cooled circulation system includes circulating water paths connected to the controller 2 and the oil cooler 6, respectively. The water-cooled circulation system also includes a water tank for supplying water. The water-cooling path is combined... Figure 12 As shown, cooling water flows from the controller outlet 3515 to the oil cooler inlet 3514, enters the oil cooler, cools the high-temperature oil inside the electric drive, and finally enters the external water circuit, forming the entire cycle.

[0060] In this embodiment, the controller 2 is installed above the reducer 1 and the motor 3, and the water cooling pipe is directly connected to the oil cooler 6, eliminating the need for an additional independent heat dissipation module, reducing the overall size of the electric drive assembly, and further improving the space utilization of the vehicle.

[0061] The water-cooled circulation system removes the heat generated by the controller 2 during operation through the circulating water circuit, and sends it to the oil cooler 6 to exchange heat with the high-temperature oil. This reduces the temperature of the controller's core components, prevents circuit performance degradation or failure due to overheating, and improves the control accuracy and response speed of the electric drive assembly.

[0062] The oil cooler 6 simultaneously performs the dual functions of oil cooling and controller water cooling. By sharing heat dissipation components, it reduces system redundancy and improves the integration of the cooling system. The synergistic effect of water cooling and oil cooling can enhance the overall heat dissipation capacity of the electric drive assembly, adapting to the heat management needs of the motor under high load conditions.

[0063] In some embodiments, the reducer 1 and the motor 3 are arranged coaxially, and the differential is integrated inside the reducer 1. The half-shaft assembly 7 is connected to the output end of the reducer 1 and passes through the output shaft of the motor 3. By arranging the motor 3 and the reducer 1 coaxially, and outputting the power source through the built-in half-shaft assembly, the axial integration of the power transmission path is achieved. The overall structure is axially compact, reducing lateral / longitudinal dimensional redundancy. Compared with the parallel shaft structure, it can shorten key dimensions and directly improve the overall vehicle space utilization. The coaxial design of the half-shaft assembly and the motor output shaft avoids additional space occupation and can directly free up space for the battery pack or passenger compartment, adapting to the compact space requirements of new energy vehicles and conforming to the trend of vehicle integration and miniaturization. Unlike the complex gear meshing of the planetary gear set coaxial scheme, this embodiment reduces intermediate transmission components, reduces redundant parts such as planetary gears and gear rings, reduces the number of parts and assembly precision requirements, thereby reducing manufacturing costs. At the same time, the offset coaxial design of the reducer 1 in this embodiment allows for a wide range of speed ratio selection and more precise vehicle control.

[0064] In some embodiments, the reducer 1 and the motor 3 are integrally housed through a housing, increasing the degree of integration. This integrated housing design reduces the number of connecting parts between the reducer 1 and the motor 3, simplifies the assembly process, and lowers production and maintenance costs. The housing integration also allows the reducer 1 and the motor 3 to form a compact unit, shortening their longitudinal dimension compared to a separate arrangement.

[0065] Overall, the aforementioned cooling and lubrication system solves the problem of complex parallel shaft and other structural arrangements in existing technologies, resulting in high space utilization in the vehicle. It can fully lubricate all parts inside the electric drive assembly, improve the heat dissipation efficiency of the electric drive, and effectively ensure the stability and reliability of the electric drive assembly operation.

[0066] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A cooling and lubrication system for an electric drive assembly, characterized in that, It includes a reducer (1), a motor (3), a half-shaft assembly (7) and an oil cooling circulation system. The reducer (1) includes a reducer housing (11) and a reducer gear shaft (12). The oil cooling circulation system includes an oil storage chamber (42), an oil pump (5), an oil cooler (6), a reducer oil cooling system, and a motor oil cooling system; The oil storage chamber (42) is connected to the oil cooler (6) through an oil delivery circuit; The oil pump (5) is installed on the oil delivery line and is used to drive the cooling oil to flow in the oil cooling circulation system; The oil cooler (6) is used to cool the cooling oil entering the motor oil cooling system; The oil inlet of the reducer oil cooling system is connected to the oil delivery circuit, and the oil outlet of the reducer oil cooling system is connected to the oil storage chamber (42). The reducer oil cooling system is used to introduce cooling oil into the reducer (1) to lubricate and cool the internal structure of the reducer and the reducer gear shaft (12). The oil storage chamber (42), the oil delivery circuit, the oil pump (5) and the reducer oil cooling system constitute the reducer circulating oil circuit. The oil inlet of the motor oil cooling system is connected to the oil cooler (6), and the oil outlet of the motor oil cooling system is connected to the oil storage chamber (42). The motor oil cooling system is used to introduce cooling oil into the motor (3) for lubrication and cooling. The oil storage chamber (42), the oil conveying circuit, the oil pump (5), the oil cooler (6) and the motor oil cooling system constitute a motor circulation oil circuit. The oil conveying line is equipped with a coarse filter (8) and a fine filter (4). The coarse filter (8) is located upstream of the oil pump (5), and the fine filter (4) is located downstream of the oil pump (5).

2. The cooling and lubrication system for the electric drive assembly according to claim 1, characterized in that, The oil delivery circuit between the fine filter (4) and the oil cooler (6) is connected to the oil inlet of the reducer oil cooling system.

3. The cooling and lubrication system for the electric drive assembly according to claim 1, characterized in that, The motor (3) includes a front bearing (31), a rear bearing (36), a bearing pressure plate (32), a stator assembly (35), a rotor assembly (34), an end cover (40), a cover plate (38), an eddy current sensor (37), an oil seal (39), and a sealing ring (41). The stator assembly (35) includes a housing (351) and a stator assembly (352), the stator assembly (352) includes a stator and windings, and the oil reservoir (42) is located at the bottom of the housing (351); The rotor assembly (34) is rotatably mounted inside the housing (351) at both ends via a front bearing (31) and a rear bearing (36). The rotor assembly (34) includes a shaft (341) and a rotor (342). The shaft (341) is hollow inside so that the half-shaft assembly (7) can pass through. The end cap (40) is connected to the end of the housing (351); The cover plate (38) is used to enclose the end cap (40) and the housing (351); The oil seal (39) and sealing ring (41) are installed inside the cover plate (38).

4. The cooling and lubrication system for the electric drive assembly according to claim 3, characterized in that, The housing (351) is provided with a carbon fiber brush (33) inside; and / or, the rear bearing (36) is a ceramic ball bearing.

5. The cooling and lubrication system for the electric drive assembly according to claim 3, characterized in that, The motor oil cooling system includes a stator oil cooling circuit, which includes a stator oil inlet (3518), a stator annular oil groove (3521), a stator internal oil passage (3522), and a stator oil spray hole (3523). The stator oil inlet (3518) is located on the housing (351). The stator annular oil groove (3521) is arranged around the outer periphery of the stator. The stator annular oil groove (3521) is connected to the stator oil spray hole (3523) through the stator internal oil passage (3522). The stator oil spray hole (3523) leads to the end of the winding. The oil output from the end of the winding flows into the oil storage chamber (42).

6. The cooling and lubrication system for the electric drive assembly according to claim 3, characterized in that, The motor oil cooling system also includes a rotor oil cooling circuit, which includes a housing rotor oil inlet (3516), an end cover oil circuit, a cover plate oil circuit, a half shaft assembly oil circuit, and a motor shaft oil circuit. The housing rotor oil inlet (3516) is located on the housing (351). The housing rotor oil inlet (3516) is connected to the cover plate oil circuit through the end cover oil circuit. The cover plate oil circuit is divided into a first oil circuit connected to the half shaft assembly oil circuit and a second oil circuit connected to the motor shaft oil circuit.

7. The cooling and lubrication system for the electric drive assembly according to claim 6, characterized in that, The end cap oil circuit includes an end cap oil inlet (401), an end cap oil outlet (402) and an end cap drain (403) provided on the end cap (40), and the end cap oil inlet (401) and the end cap oil outlet (402) are connected to each other; The cover plate oil circuit includes a first oil hole (381), a second oil hole (382), and a third oil hole (383) provided on the cover plate (38). The end cap oil outlet (402) is connected to the first oil hole (381). The second oil hole (382) and the third oil hole (383) are respectively connected to both sides of the first oil hole (381). The second oil hole (382) is connected to the half shaft assembly oil circuit, and the third oil hole (383) is connected to the motor shaft oil circuit.

8. The cooling and lubrication system for the electric drive assembly according to claim 6, characterized in that, The half-shaft assembly (7) includes a small half-shaft (71) and a half-shaft bearing (72), and the small half-shaft (71) is provided with a half-shaft spline inside; The oil passage of the half-shaft assembly includes an inclined oil groove (712) and an oil slinger hole (711). The inclined oil groove (712) extends axially on the small half-shaft (71), and the oil slinger hole (711) penetrates radially on the small half-shaft (71). The inclined oil groove (712) communicates with the spline surface of the half-shaft. The oil slinger hole (711) is used to guide the cooling oil to the half-shaft bearing (72) and the oil seal (39).

9. The cooling and lubrication system for the electric drive assembly according to claim 6, characterized in that, The motor shaft oil circuit includes a first oil hole (3411), a second oil hole (3412), a third oil hole (3413), and a fourth oil hole (3414) distributed along the shaft (341). The first oil hole (3411) is used to pass oil to the rear bearing (36) of the motor, the second oil hole (3412) and the third oil hole (3413) are used to pass oil to the rotor (342), and the fourth oil hole (3414) is used to pass oil to the front bearing (31).

10. The cooling and lubrication system for the electric drive assembly according to claim 1, characterized in that, The reducer (1) and the motor (3) are also provided with a controller (2). The cooling and lubrication system also includes a water cooling circulation system for cooling the controller (2). The water cooling circulation system includes a circulating water path that is connected to the controller (2) and the oil cooler (6) respectively.

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