Lubricating structure of differential mounting cavity of electric drive axle

Abstract

The utility model discloses a lubricating structure for a differential mounting cavity of an electric drive axle. The lubricating structure mainly comprises an electric drive axle shell and the differential mounting cavity in the electric drive axle shell. An oil pool is arranged on the lower portion of a differential installation cavity, bearing pedestals with integrated die-casting bearing pedestal bodies are arranged on the two sides of the cavity, and a closed-loop lubricating system is formed in cooperation with an upper flow guide groove, a lubricating oil channel and a lower oil return groove. The main reduction gear adopts a helical gear structure, drives oil pool lubricating oil to enter the lubricating oil channel through the diversion trench during rotation, and returns to an oil pool through the oil return groove after being shunted to lubricate the bearing seat through the branch oil channel. The oil blocking part and the wedge-shaped oil distributing part are innovatively arranged, multi-stage distribution of oil is achieved, and the problems of oil retention and unsmooth circulation of a traditional structure are effectively solved through cooperation with a flow guide / oil return channel formed by the trapezoidal bearing seat body. According to the structure, the lubricating oil capacity is reduced, the bearing lubrication coverage rate is increased, the transmission efficiency is improved, and the manufacturing cost is optimized.

Description

Technical Field

[0001] This utility model relates to the field of drive axles, specifically to a lubrication structure for the differential mounting cavity of an electric drive axle. Background Technology

[0002] As a core component of vehicle power transmission, the electric drive axle assembly's structural design directly affects transmission efficiency and reliability. Traditional drive axle assemblies typically include a drive axle housing and an integrated main reducer, differential, and half-shaft assembly. The driven gear of the main reducer often uses a helical bevel gear structure, and the differential is supported within the drive axle housing by bearings.

[0003] However, this type of structure has the following significant drawbacks: To meet the load-bearing strength requirements, the differential mounting cavity and half-shaft sleeve mounting cavity of the drive axle housing are large in size, resulting in high internal lubricant capacity requirements, disordered lubricant circulation path, low stirring efficiency, additional energy loss, and increased lubrication costs; Although traditional helical bevel gears can carry the bottom lubricant through tooth surface rotation, their tooth profile characteristics cause the oil to mainly splash along the helical tooth side of the bevel gear, forming a stagnant area on the back side of the bevel gear, further reducing lubrication efficiency; The bearing housings at both ends of the differential housing are integrally die-cast with the electric drive axle housing, and the mounting surface of the bearing housing for mounting the bearing cover is on the same plane as the rear reinforcing ring, lacking a flow guiding design, which causes the lubricant to flow obstructed near the bearing housing, making it difficult for the oil to circulate, exacerbating the problem of low bearing lubrication efficiency. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a drive axle assembly with an improved lubrication system. This is achieved by using helical cylindrical gears as the driven gears in the main reducer and optimizing the lubrication path, thereby improving the efficiency of lubricating oil circulation and solving the problem of insufficient lubrication of key components.

[0005] The specific technical solution adopted in this utility model is as follows:

[0006] A lubrication structure for the differential mounting cavity of an electric drive axle includes an electric drive axle housing. An oil sump is located at the lower part of the differential mounting cavity within the electric drive axle housing. The differential is rotatably mounted within the differential mounting cavity. A portion of the main reduction gear fixedly connected to the differential contacts the oil sump. The cavity opening of the differential mounting cavity is provided with a flange for connecting an end cover. The differential mounting cavity is characterized by: bearing seats for supporting the differential on both sides; a lubricating oil passage connecting the bearing seats to the flange for connecting the end cover and communicating with the half-shaft sleeve mounting cavity; lubricating oil guide grooves on the left and right sides of the upper cavity wall of the differential mounting cavity, communicating with the lubricating oil passage; and return oil grooves on the left and right sides of the lower part of the differential mounting cavity, one end of which communicates with the lubricating oil passage and the other end with the oil sump. Lubricating oil is carried from the oil sump to the guide grooves via the main reduction gear, and then flows back to the oil sump through the lubricating oil passage and return oil grooves, thus forming a lubricating oil circulation channel within the differential mounting cavity.

[0007] Preferably, the upper cavity wall of the differential mounting cavity is provided with an oil baffle extending toward the center of the differential mounting cavity. The upper edge of the oil baffle and the upper cavity wall of the differential mounting cavity form a first oil distribution channel, and the side edge of the oil baffle and the bearing seat form a second oil distribution channel. The first oil distribution channel and the guide groove are located on the same extension line.

[0008] Preferably, the bearing housing includes a bearing cover and a bearing housing body integrally die-cast with the electric drive axle housing. The bearing housing body has a trapezoidal axial cross-section, with a guide groove formed between the upper inclined surface and the upper cavity wall of the differential mounting cavity, and an oil return groove formed between the lower inclined surface and the lower cavity wall of the differential mounting cavity.

[0009] Preferably, the bearing housing extends toward the first oil channel to form a wedge-shaped oil distribution section, which diverts the lubricating oil into the guide groove and the second oil channel.

[0010] Preferably, the oil inlet of the guide groove and the oil outlet of the return groove are both expanded to form a funnel-shaped opening.

[0011] Preferably, the main reduction gear is a helical cylindrical gear.

[0012] The beneficial effects of this utility model are as follows:

[0013] 1. High-efficiency lubrication circulation system design: The rotation of the main reduction gear carries the lubricating oil from the oil sump into the guide channel. The guide channel, lubricating oil passage, and return oil channel form a closed loop circulation, improving the lubricating oil flow efficiency. Compared with the traditional structure, the required amount of lubricating oil is reduced, and the lubricating oil circulates orderly within the differential mounting cavity, effectively reducing gear churning losses.

[0014] 2. Precise distribution of lubricating oil improves its utilization rate: The oil baffle blocks most of the lubricating oil, while a small portion enters the first oil distribution channel. The lubricating oil entering the first oil distribution channel flows from the wedge-shaped oil distribution section into the guide groove and the second oil distribution channel, achieving multi-stage lubricating oil distribution, precisely controlling the flow direction of the lubricating oil, and improving its utilization rate. The lubricating oil entering the guide groove and the lubricating oil entering the second oil distribution channel are used to lubricate the tapered roller bearings installed in the bearing housing, respectively.

[0015] 3. The main reducer gear is a helical cylindrical gear. Compared with the traditional helical bevel gear, it can make the cooling oil splash towards both sides of the main reducer gear, eliminating the problem of oil stagnation on one side of the helical bevel gear and forming an orderly circulation of oil. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] Figure 2 This is a schematic diagram of the assembly structure of this utility model.

[0018] Wherein: 1-Electric drive axle housing, 6-Differential, 7-Main reduction gear, 8-Bearing housing, 14-Differential mounting cavity, 15-Half shaft sleeve mounting cavity, 16-Oil sump, 17-Lubricating oil passage, 18-Lubricating oil guide groove, 19-Oil return groove, 20-Oil baffle, 21-First oil distribution passage, 22-Second oil distribution passage, 23-Wedge-shaped oil distribution part, 24-Flange, 8-Bearing housing, 81-Bearing cover, 82-Bearing housing body Detailed Implementation

[0019] like Figures 1 to 2 As shown, a lubrication structure for the differential mounting cavity of an electric drive axle includes an electric drive axle housing 1. An oil sump 16 is provided at the lower part of the differential mounting cavity 14 within the electric drive axle housing 1. A differential 6 is rotatably mounted in the differential mounting cavity 14. The differential 6 includes a differential housing and a differential mechanism. A main reduction gear 7 is bolted to a flange on the differential housing. A portion of the main reduction gear 7 contacts the oil sump 16. The opening of the differential mounting cavity 14 is provided with a flange 24 for connecting an end cover. The differential mounting cavity 14 has two sides... A bearing housing 8 is provided for supporting the differential 6. The differential 6 is supported in the bearing housing 8 by a tapered roller bearing. A lubricating oil passage 17 is provided between the bearing housing 8 and the flange 24 for connecting the end cover, which is connected to the half-shaft sleeve mounting cavity 15. Lubricating oil guide grooves 18 are respectively provided on the left and right sides of the upper cavity wall of the differential mounting cavity 14. The guide grooves 18 are connected to the lubricating oil passage 17. Oil return grooves 19 are respectively provided on the left and right sides of the lower part of the differential mounting cavity 14. One end of the oil return groove 19 is connected to the lubricating oil passage 17, and the other end is connected to the oil sump 16.

[0020] The bearing housing 8 includes a bearing cover 81 and a bearing housing body 82 integrally die-cast with the electric drive axle housing 1. The bearing housing body 82 has a trapezoidal cross-section. A guide groove 18 is formed between the upper inclined surface and the upper cavity wall of the differential mounting cavity 14, and an oil return groove 19 is formed between the lower inclined surface and the lower cavity wall of the differential mounting cavity 14. The oil inlet of the guide groove 18 and the oil outlet of the oil return groove 19 are both expanded to form a trumpet-shaped opening. The trumpet-shaped opening gradually decreases in size from the oil inlet to the inside of the guide groove 18 or the oil return groove 19. The structure is used to collect and guide the flow of lubricating oil. The lubricating oil is carried from the oil sump to the guide groove 18 through the main reduction gear 7, and then flows back to the oil sump 16 through the lubricating oil passage 17 and the return oil groove 19, so that a lubricating oil circulation channel is formed in the differential mounting cavity 14. The main reduction gear 7 is a helical cylindrical gear. Compared with the helical bevel gear in the prior art, the helical cylindrical gear can make the cooling oil splash towards both sides of the main reduction gear 7, preventing the problem of oil stagnation formed on the helical bevel gear and increasing the circulation rate.

[0021] The upper cavity wall of the differential mounting cavity 14 is provided with an oil-blocking part 20 extending towards the center of the differential mounting cavity 14. The oil-blocking part 20 is approximately triangular. The upper edge of the oil-blocking part 20 and the upper cavity wall of the differential mounting cavity 14 form a first oil channel 21. The side edge of the oil-blocking part 20 and the bearing housing 8 form a second oil channel 22. The first oil channel 21 and the guide groove 18 are located on the same extension line. The oil-blocking part 20 blocks most of the lubricating oil carried by the main reduction gear 7. Most of the lubricating oil returns to the oil sump, and a small part of the lubricating oil enters the first oil channel 21. The bearing housing 8 extends toward the first oil channel 21 to form a wedge-shaped oil-blocking part 23, but the wedge-shaped oil-blocking part 23 does not extend into the first oil channel 21. The wedge-shaped oil-blocking part 23 diverts the lubricating oil into the guide groove 18 and the second oil channel 22. The lubricating oil entering the guide groove 18 and the lubricating oil entering the second oil channel 22 are used to lubricate the two sides of the tapered roller bearing, respectively.

[0022] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications made to the present utility model by those skilled in the art without departing from the spirit of the present utility model shall fall within the protection scope of the present utility model.

Claims

1. A lubricating structure of a differential mounting cavity of an electric drive axle, comprising an electric drive axle housing (1), a lower part of a differential mounting cavity (14) of the electric drive axle housing (1) is provided with an oil pool (16), a differential (6) is rotatably arranged in the differential mounting cavity (14), a part of a main reduction gear (7) fixedly connected to the differential (6) is in contact with the oil pool (16), a cavity opening of the differential mounting cavity (14) is provided with a flange (24) for connecting an end cover, characterized in that: The differential mounting cavity (14) is provided with bearing seats (8) on both sides for supporting the differential (6), and the bearing seats (8) are provided with lubricating oil channels (17) communicating with half shaft sleeve mounting cavities (15) between the flanges (24) for connecting end covers, the upper cavity walls of the differential mounting cavities (14) are provided with lubricating oil guide grooves (18) on the left and right sides, the guide grooves (18) communicate with the lubricating oil channels (17), the lower left and right sides of the differential mounting cavities (14) are provided with oil return grooves (19), one end of the oil return grooves (19) communicates with the lubricating oil channels (17), and the other end communicates with oil pools (16), lubricating oil is brought to the guide grooves (18) from the oil pools by the main reduction gears (7), and flows back to the oil pools (16) through the lubricating oil channels (17) and the oil return grooves (19), so that a lubricating oil circulation channel is formed in the differential mounting cavities (14). ​ 2. The lubrication structure of the differential mounting cavity of an electric drive axle according to claim 1, characterized in that: The upper cavity walls of the differential mounting cavities (14) are provided with oil blocking parts (20) extending to the centers of the differential mounting cavities (14), the upper edges of the oil blocking parts (20) form first oil distribution channels (21) with the upper cavity walls of the differential mounting cavities (14), the side edges of the oil blocking parts (20) form second oil distribution channels (22) with the bearing seats (8), and the first oil distribution channels (21) and the guide grooves (18) are located on the same extension line.

3. The lubrication structure of the differential mounting cavity of an electric drive axle according to claim 1, characterized in that: The bearing seats (8) include bearing covers (81) and bearing seat bodies (82) integrally pressure-cast with the electric drive axle housings (1), the bearing seat bodies (82) are trapezoidal in axial section, the upper inclined surface of the bearing seat bodies (82) forms the guide grooves (18) with the upper cavity walls of the differential mounting cavities (14), and the lower inclined surface of the bearing seat bodies (82) forms the oil return grooves (19) with the lower cavity walls of the differential mounting cavities (14).

4. The lubrication structure of the differential mounting cavity of an electric drive axle according to claim 2, characterized in that: The bearing seats (8) extend toward the first oil distribution channels (21) to form wedge-shaped oil distribution parts (23) for distributing lubricating oil into the guide grooves (18) and the second oil distribution channels (22).

5. The lubrication structure of the differential mounting cavity of an electric drive axle according to claim 1, characterized in that: The oil inlet of the guide groove (18) and the oil outlet of the oil return groove (19) are both expanded to form trumpet-shaped openings.

6. The lubrication structure of a differential mounting cavity of an electric drive axle according to claim 1, characterized in that: The main reduction gears (7) are helical cylindrical gears.

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