Centralized lubrication electric drive axle

Abstract

The invention provides a centralized lubrication electric drive axle which comprises an axle housing, and driving parts are fixedly arranged at the two ends of the axle housing. The cooling and lubricating system is used for cooling and circulating lubricating oil; an oil bottom box is fixedly arranged on the axle housing, an oil suction port is formed in the bottom of the oil bottom box and communicated with an inlet of a cooling and lubricating system through a pipeline, and an outlet of the cooling and lubricating system is communicated with oil inlets of driving components on the left side and the right side through oil inlet pipes respectively. An oil return pipe for communicating the oil outlet of the driving part on each side with the oil bottom box is arranged in the oil bottom box; when the axle housing inclines, the oil return ports of the two oil return pipes are located above the oil surface of the oil bottom box all the time, and the oil suction port is located below the oil surface all the time.

Description

Technical Field

[0001] The invention belongs to the field of wheel-side motor lubrication of vehicles, and in particular relates to a centralized lubrication electric drive axle. Background Art

[0002] The existing wheel-side motor drive axle has the following problems: ① the use of round wire motors, low power density and backward technology; ② low integration, low mutual integration between the motor, reducer and bridge, heavy weight and small channel space; ③ complex transmission structure, low efficiency and heavy weight of two-stage parallel shafts, affecting channel space; ④ the use of segmented bridge housing (reducer housing, motor housing, bridge housing middle section), which is not conducive to lightweight; ⑤ the seal between the motor and the reducer is prone to failure and cause motor failure; ⑥ the oil seal between the motor and the reducer needs to be replaced regularly, and the maintenance cost is high; ⑦ the reducer splash lubrication and oil stirring loss are high and the efficiency is low; ⑧ the water-cooled motor is large in size and has low power density and torque density. For example, the patents "CN102139628B A wheel-side drive axle", "CN102139629A Wheel-side drive axle", "CN110654224B Wheel-side drive system and structure in the vehicle.

[0003] Patent No. US20240218971A1 adopts an oil-cooled flat-wire distributed wheel-side electric drive bridge, in which the wheel-side electric drive bridge oil pans are distributed at the bottom of the motors at both ends, and the oil pump is installed in the center of the bridge housing. Features: ① The motor is large and heavy. ② When the vehicle is on an inclined road, the oil in the oil pan of the motor on one side is easily emptied. The patent uses a specially designed oil pump to ensure that the oil pump can continue to pump the oil on the other side when the oil on one side is emptied. The oil pump cost is high. ③ When the road tilts, the oil is easily concentrated in the oil pan of the motor on one side. At this time, the oil level rises and the rotor will stir the cooling oil, affecting the efficiency of the motor. ④ The oil pan is designed on the motor. If the reducer lubricating oil enters the oil pan of the motor, the impurities such as iron filings inside are easily adsorbed on the motor. Therefore, the first-stage reducer adopts oil stirring lubrication and the motor does not share lubrication, and the system efficiency is low. The dirty oil in the motor oil pan is easy to backflow into the motor, causing motor insulation failure. Summary of the invention

[0004] The invention provides a centralized lubrication electric drive axle.

[0005] The objective of the present invention is achieved in the following manner: a centralized lubrication electric drive bridge, comprising a bridge housing, drive components fixedly arranged at both ends of the bridge housing; and also comprising a cooling lubrication system for cooling and circulating lubricating oil; an oil pan is fixedly arranged on the bridge housing, an oil suction port is arranged at the bottom of the oil pan, the oil suction port is connected with the inlet of the cooling lubrication system through a pipeline, and the outlet of the cooling lubrication system is connected with the oil inlets of the drive components on the left and right sides respectively through an oil inlet pipe; an oil return pipe is arranged in the oil pan to connect the oil outlet of each side of the drive component with the oil pan respectively; when the bridge housing is tilted, the oil return ports of the two oil return pipes are always located above the oil level of the oil pan, and the oil suction port is always located below the oil level.

[0006] The oil pan is arranged at the middle position of the bridge housing; the two oil return ports are arranged above the center position of the oil pan; and the oil suction port is located at the center position of the bottom of the oil pan.

[0007] A groove is arranged on one side surface of the bridge housing, and the side of the bridge housing with the groove is arranged upwards. The groove serves as an oil pan, and a cover plate is fixedly arranged on the top and sealed.

[0008] Axle housing oil baffles are respectively arranged on the left and right sides of the oil return port and the oil suction port in the oil pan to divide the oil pan into three parts from left to right; a through hole is arranged at the bottom of each axle housing oil baffle.

[0009] Each of the driving components includes an integrated motor and an integrated reducer; the motor and the integrated reducer include a common oil channel; the common oil channel is connected to the oil inlet, and at least one first branch oil channel leading to the internal oil circuit of the motor and at least one second branch oil channel leading to the internal oil circuit of the integrated reducer are arranged on the common oil channel; the oil outlet of the motor is connected to the oil return pipe; the oil outlet of the integrated reducer is connected to the inside of the oil pan through a second oil return pipe.

[0010] The motor and the integrated reducer include a common electric reducer common end cover, in which the common oil passage is arranged; the end of the integrated reducer away from the motor is connected to the wheel-end planetary reducer, and an oil retaining ring is installed at the position where the oil seal is installed on the input shaft of the electric reducer common end cover instead of the oil seal; an oil retaining ring is installed at the position where the oil seal is installed between the wheel-end planetary reducer and the integrated reducer, instead of the oil seal; the electric drive axle transmission part uses the same lubricating oil.

[0011] The two ends of the bridge housing are directly connected to the reducer housing respectively, the electric reducer common end cover is connected to the reducer housing and is not connected to the bridge housing; the motor is connected to the electric reducer common end cover to realize the common end cover integration of the motor and the reducer, and the other end of the reducer housing is connected to the wheel-end planetary reducer; the wheel-end planetary reducer is connected to the brake disc, the brake assembly is connected to the reducer housing, the support arm and the thrust rod are connected to the bridge housing, and the shock absorber and the airbag are connected to the support arm.

[0012] The cooling and lubrication system includes a coarse filter, a fine filter, an oil pump, and an oil cooler; the oil suction port is connected to the coarse filter inlet through a pipeline, the coarse filter outlet is connected to the oil pump inlet through a pipeline, the oil pump outlet is connected to the oil cooler inlet through a pipeline, the oil cooler outlet is connected to the fine filter inlet through a pipeline, and the fine filter outlet is connected to the oil inlets of the driving components on the left and right sides through two oil inlet pipes.

[0013] The cooling and lubrication system also includes an oil circuit board arranged at the rear end of the bridge housing, and the coarse filter, fine filter, oil pump, and oil cooler are all fixedly arranged on the oil circuit board. A channel is arranged inside the oil circuit board to connect the coarse filter and the oil pump, the oil pump and the oil cooler, and the oil cooler and the fine filter.

[0014] Beneficial effects: Compared with the prior art, the present invention has the following advantages: First, the oil pan and the bridge housing are integrated to realize centralized lubrication of the motors at both ends, reducing the size and weight of the motors; Second, the motor and the reducer are lubricated, cooled, share bearings and end covers together, which improves system efficiency, reduces weight, reduces axial dimensions and increases channel space; Third, the oil pump, oil cooler, coarse filter and fine filter are integrated on the oil circuit board and assembled at the rear end of the bridge housing, reducing the number of external pipelines, saving layout space and facilitating maintenance; Fourth, a special oil return design is adopted to ensure that when the vehicle tilts forward, backward or left and right, the oil in the oil pan will not flow back into the motor and the oil pump will not be emptied; Fifth, the oil seal between the motor and the integrated reducer (can also be replaced with an oil retaining ring) and the oil seal between the integrated reducer and the wheel-end planetary reducer (can also be replaced with an oil retaining ring) only require the function of oil retaining, so the oil seal does not require replacement during the entire life cycle, which greatly reduces the maintenance cost; Sixth, the bridge housing is directly connected to the reducer housing, the motor and the bridge housing are separated, and the lightweight effect is good. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 This is a schematic diagram of the interior of the oil pan when it is opened.

[0017] Figure 3 This is the distribution diagram of the oil retaining ring between the motor and the reducer (some parts irrelevant to the invention point are omitted).

[0018] Figure 4 This is the oil circuit diagram of the cooling and lubrication system.

[0019] Figure 5 It is the overall structural oil circuit diagram.

[0020] Figure 6 This is a schematic diagram of the shared oil passage for the motor and integrated reducer (irrelevant parts omitted).

[0021] Figure 7It simulates the position of the lubricating oil, oil return port and oil suction port when the vehicle is tilted.

[0022] The names of the components corresponding to the corresponding reference numerals in the figure are: 1. Cooling and lubrication system; 1a. Oil circuit board; 1b. Coarse filter; 1c. Fine filter; 1d. Oil pump; 1e. Oil cooler; 1f. Oil return pipe; 1g. Oil inlet pipe; 1h. Second oil return pipe; 2. Bridge housing; 2a. Bridge housing oil baffle plate; 2b. Cover plate; 2c. Oil suction port; 2d. Oil pan; 3. Motor; 4. Integrated reducer; 4a. Reducer housing; 4b. Input common bearing; 4c. Electric reducer common end cover; 4d. Common oil channel; 4e. First branch oil channel; 4f. Second branch oil channel; 4g. Oil inlet; 5. Wheel-end planetary reducer; 6. Support arm; 7. Connecting plate; 8. Brake disc; 9. Brake assembly; 10. Shock absorber; 11. Airbag; 12. Thrust rod; 13. Oil baffle ring; 14. Oil return port. DETAILED DESCRIPTION

[0023] In the present invention, unless otherwise clearly specified and limited, the technical terms used in this application shall be the common meanings understood by the technicians of the present invention. The terms "connected", "connected", "fixed", "set", etc. should be understood in a broad sense, and may be fixedly connected, detachably connected, or integrated; may be directly connected, or indirectly connected through an intermediate medium; may be mechanically connected or electrically connected. Unless otherwise clearly specified and limited, the first feature "on" or "below" the second feature may be that the first and second features are in direct contact, or indirectly in contact through an intermediate medium. Moreover, the first feature "above" or "above" or "above" the second feature may be that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below" or "below" or "below" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. Relational terms such as first, second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms used in the description, such as "center", "lateral", "longitudinal", "length", "width", "thickness", "height", "front", "back", "left", "right", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential", "clockwise", "counterclockwise", etc., to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation.

[0024] The following will provide a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings and specific embodiments. Figure 1-7 As shown, a centralized lubrication electric drive bridge includes a bridge housing 2, driving components are fixedly arranged at both ends of the bridge housing 2; and also includes a cooling lubrication system 1 for cooling and circulating lubricating oil; an oil pan 2d is fixedly arranged on the bridge housing 2, and an oil suction port 2c is arranged at the bottom of the oil pan 2d, and the oil suction port 2c is connected to the inlet of the cooling lubrication system 1 through a pipeline, and the outlet of the cooling lubrication system 1 is connected to the oil inlet 4g of the driving components on the left and right sides through an oil inlet pipe 1g; an oil return pipe 1f is arranged in the oil pan 2d to connect the oil outlet of each driving component with the oil pan 2d; when the bridge housing 2 is tilted, the oil return ports 14 of the two oil return pipes 1f are always located above the oil level of the oil pan 2d, and the oil suction port 2c is always located below the oil level. The setting on the bridge housing 2 here can be above, below or inside the bridge housing 2. As long as it is fixed on the bridge housing 2 and moves or tilts with the bridge housing 2, it can be fine. The cooling lubrication system 1, the driving components on both sides, and the oil pan 2d form a circulating oil circuit lubrication structure through pipelines. An oil suction port 2c is set at the bottom of the oil pan 2d, where the bottom includes the bottom surface and the position close to the bottom surface. As long as the oil pan 2d moves and tilts with the bridge housing 2, the oil suction port 2c is always below the oil level of the oil pan 2d to ensure that the oil can always be sucked. The oil suction port 2c is preferably set in the middle position of the oil pan 2d. Other positions are also possible, as long as they can always be below the oil level. The driving components here are preferably the motor 3 and the reducer. The lubrication structure of the present invention can only lubricate the motor 3, or only lubricate the reducer, or lubricate the motor 3 and the reducer at the same time. In the present invention, only one oil pan 2d is required to be set on the axle. When the oil pan 2d tilts left and right or front and back, the height of the oil level changes. As long as the oil return ports 14 of the two oil return pipes 1f are ensured to be above the oil level, the lubricating oil will not flow back into the driving components, such as the motor 3, through the oil return pipe 1f. The present invention prevents backflow when tilted by arranging the positions of the oil pan 2d, the oil suction port 2c and the oil return port 14 of the oil return pipe 1f. It has a simple structure, low cost and greatly reduces the volume and weight of the overall bridge housing 2.

[0025] The oil pan 2d is arranged at the middle position of the bridge housing 2; the two oil return ports 14 are arranged above the center position of the oil pan 2d; the oil suction port 2c is located at the center position of the bottom of the oil pan 2d. The center position of the oil pan 2d in the front, rear, left, and right directions and the center position of the bridge housing 2 in the front, rear, left, and right directions are basically located on a vertical line, but the height position may be different. The middle position and the center position here include the most central position and the position slightly deviated from the most central position; the slight deviation is sufficient as long as the oil return port 14 is located above the oil level. The height of the oil return port 14 is set according to the oil level and actual needs. The lubricating oil after cooling the driving components returns to the oil pan 2d through the oil return pipe 1f. The oil return port 14 of the oil return pipe 1f is installed at the center position above the oil level of the oil pan 2d. In this way, when the vehicle is tilted, the oil level is basically tilted around the center position of the oil level, left and right, front and back, and the front and rear and left and right positions of the oil level change, but the center oil level height basically does not change, so the lubricating oil will not flow back into the driving components such as the motor 3 through the oil return port 14 of the oil return pipe 1f. The oil suction port 2c is also designed at the center of the bottom of the lubricating oil in the oil pan 2d. When the vehicle is tilted, the oil level basically tilts left and right and front and back around the center of the oil level. The front and back and left and right positions of the oil level change in height, but the center oil level height basically does not change. Therefore, there will be no vacuum at the oil suction port 2c.

[0026] A groove is arranged on one side of the bridge housing 2, and the side of the bridge housing 2 with the groove is arranged upward, and the groove is used as an oil pan 2d, and a cover plate 2b is fixedly arranged on the top and sealed; in the case where the bottom of the existing bridge housing 2 is provided with a groove, the bridge housing 2 can be reversely installed on the vehicle, and the side with the groove is arranged upward, and the groove is used as an oil pan 2d. By using the internal closed cavity or groove of the bridge housing 2 as the oil pan 2d of the lubrication system, it is not necessary to design the oil pan 2d on the motor 3, the volume and weight of the motor 3 are reduced, and centralized lubrication is achieved. In the case where there is no groove on the bridge housing 2, or there is a groove, but the shape and size of the existing groove are not suitable for use as an oil pan 2d, the bridge housing 2 can be redesigned according to needs in the present invention, and a groove is designed on its upper surface, or the shape and size of the groove are re-arranged, so as to facilitate its use as an oil pan 2d. The cover plate 2b is arranged on the surface of the bridge housing 2 to cover the groove used as the oil pan 2d. The cover plate 2b and the oil pan 2d are fixed by screws, and the joint surfaces and gaps are sealed and connected by sealant; the sealant adopts the existing technology and will not be described in detail. A cylindrical or other shaped protrusion is arranged in the oil pan 2d, and a channel is arranged on the protrusion. The port of the channel is arranged on the protrusion in the middle of the bottom of the oil pan 2d, and the port is the oil suction port 2c. The other end of the channel is located on the outer surface of the bridge housing 2, and can be connected to the other parts through a pipeline. The oil pan 2d can also be arranged above the bridge housing 2. It is necessary to pay attention to the installation space to avoid interference, and the oil level height should preferably not exceed the oil level height of the motor 3.

[0027] A bridge housing oil baffle plate 2a is provided on the left and right sides of the oil return port 14 and the oil suction port 2c in the oil pan 2d to divide the oil pan 2d into three parts from left to right; a through hole is provided at the bottom of each bridge housing oil baffle plate 2a. The bridge housing oil baffle plate 2a can prevent the oil in the oil pan 2d from shaking violently to form ripples, and stabilize the oil surface to a certain extent. The return oil pipe 1f can pass through the bridge housing 2 or the cover plate 2b, and the bridge housing oil baffle plate 2a; the return oil pipe 1f and the bridge housing 2 or the cover plate 2b are sealed, and the sealing method can adopt the existing static sealing method, such as using sealant or sealing ring.

[0028] Each of the driving components includes an integrated motor 3 and an integrated reducer 4; the motor 3 and the integrated reducer 4 include a common oil passage 4d; the common oil passage 4d is connected to the oil inlet 4g, and the common oil passage 4d is provided with at least one first branch oil passage 4e leading to the internal oil passage of the motor 3, and at least one second branch oil passage 4f leading to the internal oil passage of the integrated reducer; the oil outlet of the motor 3 is connected to the oil return pipe 1f; the oil outlet of the integrated reducer 4 is connected to the inside of the oil pan 2d through the second oil return pipe 1h. The oil outlet of the integrated reducer 4 can be directly set on the housing of the integrated reducer 4, or can be set on one end of the motor 3 close to the oil pan 2d through the oil passage in the electric reducer common end cover 4c, in which case the oil passage in the electric reducer common end cover 4c is not connected to the oil passage of the motor 3. The second oil return pipe 1h is located at one end of the oil pan 2d and can be set above the center of the oil pan 2d like the oil return port 14, or can be set near one side of the oil pan 2d and below the oil level. After the lubricating oil flows through the motor 3, one of the ways is divided into the integrated reducer 4, which actively lubricates the reducer gears and bearings to improve the efficiency of the integrated reducer 4. The integrated reducer 4 and the motor 3 use the same lubricating oil and each adopts an independent oil return line, and the two share the oil inlet but not the return oil. There are many impurities in the lubricating oil passing through the integrated reducer 4. If the oil is returned together, it may affect the motor 3. The setting of not returning the oil together prevents impurities in the oil circuit from entering the oil circuit. The above structure is only a preferred structure, and other structures are also within the protection scope of the present invention. The lubrication structure in the present invention can also only lubricate the motor 3 or only lubricate the integrated reducer 4. When only lubricating the motor 3: an oil inlet 4g and an oil outlet are set on the motor 3, and the oil channel of the motor 3 is between the oil inlet 4g and the oil outlet. The cooling circulation system is connected to the oil inlet 4g of the motor 3 through the oil inlet pipe 1g, and the oil outlet is set above the center position of the oil pan 2d through the oil return pipe 1f. The structure of lubricating the motor 3 and the integrated reducer 4 at the same time can also be lubricated separately through pipelines. For example, the motor 3 and the integrated reducer 4 are respectively provided with their own oil inlet 4g and oil outlet, and are respectively connected to the cooling circulation system through their own oil inlet pipes 1g, and are respectively connected to the oil pan 2d through their own oil return pipes 1f.

[0029] The motor 3 and the integrated reducer 4 include a common electric reducer common end cover 4c, in which the common oil passage 4d is arranged; the end of the integrated reducer 4 away from the motor 3 is connected to the wheel-end planetary reducer 5, and an oil retaining ring 13 is installed at the position where the oil seal is installed on the input shaft of the electric reducer common end cover 4c instead of the oil seal; an oil retaining ring 13 is installed at the position where the oil seal is installed between the wheel-end planetary reducer 5 and the integrated reducer 4 instead of the oil seal; the electric drive axle transmission part uses the same lubricating oil. The motor 3 can be an oil-cooled flat wire motor 3; the integrated reducer 4 can be a first-stage parallel shaft reducer. The integrated structure of the motor 3 and the integrated reducer 4 adopts the integrated structure of the prior art.

[0030] The input shaft of the electric reduction common end cover 4c includes a left shaft and a right shaft, the left shaft is the input shaft of the integrated reducer 4, and the right shaft is the part of the motor shaft close to the motor 3; the part of the motor shaft away from the motor 3 is inserted into the inside of the integrated accelerator input shaft and fixed; the motor shaft and the integrated reducer input shaft share a bearing. That is to say, there is no bearing at the front end of the motor shaft, and the input common bearing 4b on the integrated reducer 4 is borrowed; after integration, the thickness of the end cover and the thickness of the bearing at both ends are saved axially, so the channel space can be greatly increased. The lubrication of the wheel-end planetary reducer 5 can be self-lubricated, and the oil circuit and oil pan 2d are not shared with the integrated motor 3 and the integrated reducer 4, but the same lubricating oil can be used. In this case, a small amount of oil can be allowed to cross between the motor 3, the integrated reducer 4, and the wheel-end planetary reducer 5 inside the entire electric drive bridge. Therefore, there is no need to use an oil seal with high sealing and no oil cross-contamination, which saves the cost of regular maintenance of the oil seal.

[0031] The two ends of the bridge housing 2 are directly connected to the reduction housing 4a respectively, and the electric reduction common end cover 4c is connected to the reduction housing 4a and is not connected to the bridge housing 2; the motor 3 is connected to the electric reduction common end cover 4c to realize the integration of the common end cover of the motor 3 and the reducer, and the other end of the reduction housing 4a is connected to the wheel-end planetary reducer 5; the wheel-end planetary reducer 5 is connected to the brake disc 8, the brake assembly 9 is connected to the reduction housing 4a, the support arm 6 and the thrust rod 12 are connected to the bridge housing 2, and the shock absorber 10 and the airbag 11 are connected to the support arm 6; the upper end of the motor 3 is also provided with a connecting plate 7, which is used to connect the opening on the bridge housing. The reduction housing 4a is the reducer housing. The above components constitute a structure of the electric drive bridge assembly. The present invention designs an integrated bridge housing 2 that is directly connected to the integrated reducer 4, and the motor 3 can be independent and does not need to be integrated with the bridge housing 2. The lightweight level of the entire bridge can be improved, and the reliability and NVH performance of the motor 3 can be improved.

[0032] The cooling and lubricating system 1 includes a coarse filter 1b, a fine filter 1c, an oil pump 1d, and an oil cooler 1e; the oil suction port 2c is connected to the coarse filter 1b inlet through a pipeline, the coarse filter 1b outlet is connected to the oil pump 1d inlet through a pipeline, the oil pump 1d outlet is connected to the oil cooler 1e inlet through a pipeline, the oil cooler 1e outlet is connected to the fine filter 1c inlet through a pipeline, and the fine filter 1c outlet is connected to the oil inlet 4g of the driving components on the left and right sides through two oil inlet pipes 1g. Specifically: the fine filter 1c outlet is connected to the oil inlet 4g of the motor 3 on the left and right sides through two oil inlet pipes 1g; after lubrication, the oil outlet of the motor 3 is connected to the oil pan 2d through the oil return pipe 1f, and the oil outlet of the integrated reducer 4 enters the oil pan 2d through the second oil return pipe 1h. The specific structure and installation method of the coarse filter 1b, the fine filter 1c, the oil pump 1d, and the oil cooler 1e belong to the prior art and will not be described in detail.

[0033] The cooling and lubricating system 1 also includes an oil circuit board 1a disposed at the rear end of the bridge housing 2. The coarse filter 1b, fine filter 1c, oil pump 1d, and oil cooler 1e are all fixedly disposed on the oil circuit board 1a. A channel is disposed inside the oil circuit board 1a to connect the coarse filter 1b and the oil pump 1d, the oil pump 1d and the oil cooler 1e, and the oil cooler 1e and the fine filter 1c. The oil return port 14 can also be connected to the coarse filter 1b through the bridge housing 2 and the internal channel of the oil circuit board 1a. The cooling and lubricating system 1 is integrated at the rear end of the bridge housing 2, and does not exceed the upper and lower planes of the bridge housing 2, and does not affect the interior space and ground clearance. The components are connected through the oil channel inside the oil circuit board 1a, which saves a large number of external connecting pipelines. Of course, external pipelines can also be used for connection.

[0034] The present invention has the following advantages: First, the oil pan 2d is integrated with the bridge housing 2, which realizes the centralized lubrication of the motors 3 at both ends and reduces the volume and weight of the motors 3; Second, the motor 3 and the reducer are lubricated, cooled, have common bearings and end covers, which improves the system efficiency, reduces the weight, reduces the axial size and increases the channel space; Third, the oil pump 1d, oil cooler 1e, coarse filter 1b and fine filter 1c are integrated on the oil circuit board 1a and assembled at the rear end of the bridge housing 2, which reduces the number of external pipelines, saves layout space and is convenient for maintenance; Fourth, the use of special The oil return design ensures that when the vehicle tilts forward, backward or left or right, the oil in the oil pan 2d does not flow back into the motor 3 and the oil pump 1d does not emptied; Fifth: the oil seal between the motor 3 and the integrated reducer 4 (which can also be replaced with an oil retaining ring 13), and the oil seal between the integrated reducer 4 and the wheel-end planetary reducer 5 (which can also be replaced with an oil retaining ring 13) only require the function of oil retaining, so the oil seal does not require replacement during the entire life cycle, which greatly reduces the maintenance cost; Sixth: the bridge housing 2 is directly connected to the reduction housing 4a, the motor 3 and the bridge housing 2 are separated, and the lightweight effect is good.

[0035] During specific implementation: the lubricating oil is sucked out from the oil pan 2d through the oil suction port 2c, filtered by the coarse filter 1b, sucked out by the oil pump 1d and flows into the oil cooler 1e, the lubricating oil is cooled by the oil cooler 1e and flows into the fine filter 1c, filtered by the fine filter 1c and transported to the flat wire motor 3 and the integrated reducer 4 at both ends through the oil inlet pipe 1g respectively, and after lubrication and cooling, the lubricating oil returns to the oil pan 2d through the return oil pipe 1f and the second return oil channel to form a circulation.

[0036] The present invention uses the latest oil-cooled flat wire motor 3, which has higher power density, torque density and efficiency; uses the latest motor 3 and reducer integration technology, which greatly improves the channel width, efficiency and lightweight; uses centralized lubrication technology to achieve vector control of lubrication and cooling, and uses lubrication and bridge housing 2 integration technology to greatly reduce the volume and weight of the entire bridge; the entire bridge integrates the current advanced oil-cooled flat wire technology, electric reduction integration technology and centralized lubrication and cooling technology, and the overall lightweight, efficiency, NVH, channel width and other comprehensive performance are greatly improved.

[0037] The technical features of the above-mentioned embodiments can be combined arbitrarily, and as long as there is no contradiction in the combination of these technical features, they should be considered as the scope of this specification. Without departing from the overall concept of the present invention, the technical solution according to the present invention and the equivalent replacement or change, as well as the changes and improvements made, should also be regarded as the protection scope of the present invention.

Claims

1. A centralized lubrication electric drive axle, comprising an axle housing, drive components fixedly arranged at both ends of the axle housing; and a cooling and lubrication system for cooling and circulating lubricating oil; characterized in that: An oil pan is fixedly arranged on the bridge housing, and an oil suction port is arranged at the bottom of the oil pan, and the oil suction port is connected with the inlet of the cooling and lubrication system through a pipeline, and the outlet of the cooling and lubrication system is respectively connected with the oil inlets of the driving components on the left and right sides through the oil inlet pipe; an oil return pipe is arranged in the oil pan to connect the oil outlet of the driving components on each side with the oil pan; when the bridge housing is tilted, the oil return ports of the two oil return pipes are always located above the oil level of the oil pan, and the oil suction port is always located below the oil level.

2. According to claim 1, a centralized lubrication electric drive axle is characterized by: The oil pan is arranged at the middle position of the bridge housing; the two oil return ports are arranged above the center position of the oil pan; and the oil suction port is located at the center position of the bottom of the oil pan.

3. According to claim 1, the centralized lubrication electric drive axle is characterized by: A groove is arranged on one side surface of the bridge housing, and the side of the bridge housing with the groove is arranged upwards. The groove serves as an oil pan, and a cover plate is fixedly arranged on the top and sealed.

4. According to claim 3, a centralized lubrication electric drive axle is characterized by: Axle housing oil baffles are respectively arranged on the left and right sides of the oil return port and the oil suction port in the oil pan to divide the oil pan into three parts from left to right; a through hole is arranged at the bottom of each axle housing oil baffle.

5. The centralized lubrication electric drive axle according to claim 1, characterized in that: Each of the driving components includes an integrated motor and an integrated reducer; the motor and the integrated reducer include a common oil channel; the common oil channel is connected to the oil inlet, and at least one first branch oil channel leading to the internal oil circuit of the motor and at least one second branch oil channel leading to the internal oil circuit of the integrated reducer are arranged on the common oil channel; the oil outlet of the motor is connected to the oil return pipe; the oil outlet of the integrated reducer is connected to the inside of the oil pan through a second oil return pipe.

6. The centralized lubrication electric drive axle according to claim 5, characterized in that: The motor and the integrated reducer include a common electric reducer common end cover, in which the common oil passage is arranged; the end of the integrated reducer away from the motor is connected to the wheel-end planetary reducer, and an oil retaining ring is installed at the position where the oil seal is installed on the input shaft of the electric reducer common end cover instead of the oil seal; an oil retaining ring is installed at the position where the oil seal is installed between the wheel-end planetary reducer and the integrated reducer; and the electric drive axle transmission part uses the same lubricating oil.

7. The centralized lubrication electric drive axle according to claim 6, characterized in that: The input shaft of the electric reducer common end cover includes a left shaft and a right shaft, the left shaft is the input shaft of the integrated reducer, and the right shaft is the part of the motor shaft close to the motor; the part of the motor shaft away from the motor is inserted into the interior of the integrated accelerator input shaft and fixed; the motor shaft and the integrated reducer input shaft share a bearing.

8. The centralized lubrication electric drive axle according to claim 6, characterized in that: The two ends of the bridge housing are directly connected to the reducer housing respectively, the electric reducer common end cover is connected to the reducer housing and is not connected to the bridge housing; the motor is connected to the electric reducer common end cover to realize the common end cover integration of the motor and the reducer, and the other end of the reducer housing is connected to the wheel-end planetary reducer; the wheel-end planetary reducer is connected to the brake disc, the brake assembly is connected to the reducer housing, the support arm and the thrust rod are connected to the bridge housing, and the shock absorber and the airbag are connected to the support arm.

9. A centralized lubrication electric drive axle according to any one of claims 1 to 8, characterized in that: The cooling and lubrication system includes a coarse filter, a fine filter, an oil pump, and an oil cooler; the oil suction port is connected to the coarse filter inlet through a pipeline, the coarse filter outlet is connected to the oil pump inlet through a pipeline, the oil pump outlet is connected to the oil cooler inlet through a pipeline, the oil cooler outlet is connected to the fine filter inlet through a pipeline, and the fine filter outlet is connected to the oil inlets of the driving components on the left and right sides through two oil inlet pipes.

10. The centralized lubrication electric drive axle according to claim 9, characterized in that: The cooling and lubrication system also includes an oil circuit board arranged at the rear end of the bridge housing, and the coarse filter, fine filter, oil pump, and oil cooler are all fixedly arranged on the oil circuit board. A channel is arranged inside the oil circuit board to connect the coarse filter and the oil pump, the oil pump and the oil cooler, and the oil cooler and the fine filter.

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