Multi-gear electric drive axle assembly structure

Abstract

The invention discloses a multi-gear electric drive axle assembly structure which effectively utilizes the spaces on the two sides of an axle assembly, improves the overall reliability of an electric drive axle, and enables a lubricating structure to be simple and the lubricating reliability to be high. The axle assembly comprises an axle sub-assembly; the auxiliary box gearbox comprises an auxiliary box shell, an auxiliary box rear cover, an auxiliary box oil pipe and an auxiliary box gear shaft assembly. An auxiliary box motor; the main box gearbox comprises a main box shell, a main box gear shaft assembly, a main box rear cover, an oil pump, a main box upper oil pipe and a main box lower oil pipe. A main box motor; and an inter-bridge oil pipe. The auxiliary box motor and the auxiliary box gearbox form an auxiliary box sub-assembly, the main box motor and the main box gearbox form a main box sub-assembly, and the main box sub-assembly and the auxiliary box sub-assembly are located on the two sides of the axle sub-assembly respectively. A main box shell of the main box gearbox and an auxiliary box shell of the auxiliary box gearbox are fixedly connected to the positions, corresponding to shell bodies on the two sides of a differential mechanism gear, of the axle subassembly through bolts respectively, and a main box external oil way connector is arranged on the main box rear cover.

Description

Technical Field

[0001] The present invention relates to the technical field of electric drive axle structures, and in particular to a multi-speed electric drive axle assembly structure. Background Art

[0002] Integration and high efficiency are the inevitable trends in the development of automotive electric drive systems. The electric drive axle structure eliminates the drive shaft and spiral bevel gears, effectively reducing the size of the transmission system and improving the transmission efficiency. It is one of the most promising development directions for new energy assemblies for commercial vehicles.

[0003] However, when the existing electric drive axle assembly has both a main box gearbox and an auxiliary box gearbox, it is generally arranged that the two gearboxes are arranged on one side of the axle sub-assembly, and an oil pump is independently provided in each gearbox, which results in that each gearbox needs to be independently provided with an oil pump, and because the oil pump needs to match the rotation direction of the differential gear, the two gearboxes need to be provided with matching oil pump assembly structures, and the rear covers of the gearboxes need to be provided with corresponding lubricating oil circuits, which makes the entire electric drive axle assembly occupy a large volume; and because the two gearboxes are located on one side of the axle sub-assembly, the uneven mass distribution of the entire electric bridge will have an adverse effect on the suspension strength; therefore, it is urgently necessary to develop a new multi-speed electric drive axle assembly structure. Summary of the invention

[0004] In view of the above problems, the present invention provides a multi-speed electric drive axle assembly structure, which effectively utilizes the space on both sides of the axle assembly, improves the overall reliability of the electric drive axle, and makes the lubrication structure simple and the lubrication reliability high.

[0005] A multi-speed electric drive axle assembly structure, characterized in that it includes:

[0006] Bridge sub-assembly;

[0007] Auxiliary box gearbox, which includes an auxiliary box housing, an auxiliary box rear cover, an auxiliary box oil pipe, and an auxiliary box gear shaft assembly;

[0008] Auxiliary box motor;

[0009] The main box gearbox includes a main box housing, a main box gear shaft assembly, a main box rear cover, an oil pump, a main box upper oil pipe, and a main box lower oil pipe;

[0010] Main box motor;

[0011] and inter-bridge oil pipelines;

[0012] The auxiliary box motor and the auxiliary box gearbox form an auxiliary box sub-assembly, the main box motor and the main box gearbox form a main box sub-assembly, the main box sub-assembly and the auxiliary box sub-assembly are respectively located on both sides of the bridge sub-assembly, the main box housing of the main box gearbox and the auxiliary box housing of the auxiliary box gearbox are respectively fixedly connected to the housing positions on both sides of the bridge sub-assembly corresponding to the differential gear by bolts, the main box rear cover is provided with a main box external oil circuit interface, the auxiliary box housing is provided with an auxiliary box housing oil inlet, and the inter-bridge oil pipe is connected to the main box external oil circuit interface The main case gearbox is provided with an oil filter at the bottom of the cavity, and the oil pump is indirectly connected to the oil filter to pump lubricating oil. The oil pump pumps one path of oil into the main case gearbox for lubrication, and the oil pump pumps another path of oil into the auxiliary case gearbox through the inter-bridge oil pipe for lubrication. The cavity of the auxiliary case gearbox, the differential gear cavity of the axle sub-assembly, and the cavity of the main case gearbox are connected at the bottom to form a reflux area of ​​the lubricating oil, and the oil filter is located in the inner cavity area of ​​the main case gearbox in the reflux area.

[0013] It is further characterized by:

[0014] The interface between the oil pump and the rear cover of the main box is designed to be centrally symmetrical. The forward and reverse rotation of the differential gear matches the 0-degree oil pump and the 180-degree oil pump. The oil pump has two working positions, 0-degree position and 180-degree position. When the gear is reversed, the oil pump rotates and switches positions, so that the oil suction port and the oil outlet of the oil pump are swapped. Through the centrally symmetrical interface structure of the oil pump and the rear cover, when the gear is reversed, the oil pump assembly position is rotated 180 degrees, which is equivalent to the differential gear forward transmission with the 0-degree oil pump assembly, and the differential gear reverse rotation with the 180-degree oil pump assembly, which meets the oil pumping requirements of the electric drive axle in the front and rear driving directions;

[0015] The top of the main box rear cover is provided with a main box external oil circuit interface, and the main box rear cover is also provided with an oil inlet on the main box rear cover and a lubricating oil channel for the main box rear cover bearing; the lubricating oil is filtered by the oil filter, reaches the main box rear cover oil inlet channel, enters the oil pump inlet to reach the oil pump, and then is pumped out through the oil pump outlet, and is divided into the main box rear cover upper oil pipe oil channel and the main box rear cover lower oil pipe oil channel; the main box rear cover lower oil pipe oil channel is connected to the main box rear cover lower oil pipe oil hole, and the lubricating oil enters the main box lower oil pipe; the main box rear cover upper oil pipe oil channel is divided to the main box external oil circuit Interface, oil pipe oil inlet on the rear cover of the main box, and lubricating oil passage of the bearing on the rear cover of the main box; the main box external oil circuit interface is connected to the inter-bridge oil pipe so that the lubricating oil reaches the auxiliary box gearbox; the oil pipe oil inlet on the rear cover of the main box is connected to the oil pipe on the main box, so that the lubricating oil reaches the oil pipe oil inlet on the main box shell, and the lubricating oil passage of the bearing on the rear cover of the main box is connected to the bearing chamber of the input shaft of the main box, and then reaches the bearing chamber of the intermediate shaft of the rear cover of the main box through the intermediate shaft oil passage of the rear cover of the main box. The output shaft bearing chamber of the rear cover of the main box is lubricated by the lubricating oil splashed down by the above lubrication and the oil passage inside the output shaft of the main box;

[0016] The lubricating oil reaching the oil inlet of the oil pipe on the main case housing enters the input shaft bearing chamber of the main case housing through the main case housing input shaft oil passage, and then enters the main case housing intermediate shaft bearing chamber through the main case housing intermediate shaft oil passage;

[0017] The lubricating oil of the lower oil pipe of the main box is connected to the oil inlet of the lower oil pipe of the main box shell, and enters the oil outlet of the output shaft of the main box through the output shaft oil passage of the main box shell;

[0018] The lubricating oil passes through the oil outlet of the main box output shaft, one way is through the motion gap to lubricate the output shaft bearing of the main box housing, and the other way is to reach the oil channel inside the main box output shaft; the lubricating oil entering the oil channel inside the main box output shaft passes through the radial oil hole of the main box output shaft to lubricate the needle bearing, and the other way is through the axial oil hole of the main box output shaft to lubricate the output shaft bearing of the main box rear cover;

[0019] The lubricating oil from the inter-bridge oil pipe passes through the oil inlet of the auxiliary case housing, the oil inlet passage of the auxiliary case housing reaches the oil inlet of the auxiliary case oil pipe and then splits, one way connects to the auxiliary case oil pipe, the other way reaches the input shaft bearing chamber of the auxiliary case housing to lubricate the input shaft bearing of the auxiliary case housing, and then passes through the output shaft oil inlet passage of the auxiliary case housing to reach the output shaft bearing chamber of the main case housing to lubricate the output shaft bearing;

[0020] For a relatively closed electric drive axle gearbox housing, an oil discharge hole is also provided at the bottom of the auxiliary gearbox housing, which allows the active lubrication oil to smoothly return to the axle pack;

[0021] The auxiliary box oil pipe is connected to the oil inlet of the auxiliary box rear cover, and the lubricating oil enters the auxiliary box rear cover input shaft bearing chamber to lubricate the auxiliary box rear cover input shaft bearing, and then enters the auxiliary box rear cover output shaft chamber through the auxiliary box rear cover output shaft oil inlet channel to lubricate the auxiliary box rear cover output shaft bearing.

[0022] After adopting the structure of the present invention, the auxiliary box motor and the auxiliary box gearbox form an auxiliary box sub-assembly, the main box motor and the main box gearbox form a main box sub-assembly, the main box sub-assembly and the auxiliary box sub-assembly are respectively located on both sides of the bridge sub-assembly, effectively utilizing the space on both sides of the bridge assembly, and at the same time making the mass distribution on both sides of the bridge even, facilitating the suspension design of the chassis of the whole vehicle, and avoiding the adverse effect of uneven mass distribution on the suspension strength of the entire electric drive bridge; and the differential gear is meshed with the gears on both sides, and the force directions at both ends are obtuse angles, the force of the differential gear during operation will be borne by the gears at both ends at the same time, and the force directions at the obtuse angles at both ends will also Further reduce the stress on the bearings at both ends of the differential gear. The differential bearing is the end bearing, bears the largest load, and is the most likely to fail. This structure can reduce the load on the differential bearing to the greatest extent and improve the overall reliability of the electric drive axle. In addition, only an oil pump is arranged in the main box gearbox, and the inter-bridge oil pipe connects the main box external oil circuit interface and the auxiliary box housing oil inlet. The oil pump pumps one oil into the main box gearbox for lubrication, and the oil pump pumps another oil into the auxiliary box gearbox through the inter-bridge oil pipe for lubrication. This makes it necessary to only assemble the oil pump in the main box gearbox, so that the lubrication structure is simple and the lubrication reliability is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 It is a schematic diagram of the transmission principle of the present invention;

[0025] Figure 3 It is a working principle diagram of the oil pump of the present invention at 0 degree and 180 degree;

[0026] Figure 4 A three-dimensional diagram of the main box gearbox of the present invention;

[0027] Figure 5 A side view of the main box gearbox of the present invention;

[0028] Figure 6 It is a schematic diagram of the oil circuit arrangement of the main box rear cover of the main box gearbox of the present invention;

[0029] Figure 7 It is a schematic diagram of the oil circuit arrangement of the main box housing of the main box gearbox of the present invention;

[0030] Figure 8 It is a schematic diagram of the layout of the internal oil circuit of the shaft of the main box gearbox of the present invention;

[0031] Fig. 9 The three-dimensional auxiliary box gearbox of the present invention Figure 1 ;

[0032] Fig.10 The three-dimensional auxiliary box gearbox of the present invention Figure 2 ;

[0033] Fig.11 It is a schematic diagram of the oil circuit arrangement of the auxiliary box housing of the auxiliary box gearbox of the present invention;

[0034] Fig.12 It is a schematic diagram of the oil circuit arrangement of the auxiliary box rear cover of the auxiliary box gearbox of the present invention. DETAILED DESCRIPTION

[0035] A multi-speed electric drive axle assembly structure, see Figure 1-Figure 12 , which includes an axle sub-assembly 4, an auxiliary box gearbox 2, an auxiliary box motor 1, a main box gearbox 6, a main box motor 5, and an inter-bridge oil pipe 3;

[0036] The auxiliary box gearbox 2 comprises an auxiliary box housing 2.1, an auxiliary box rear cover 2.2, an auxiliary box oil pipe 2.3, and an auxiliary box gear shaft assembly 2.4;

[0037] The main box gearbox 6 comprises a main box housing 6.1, a main box gear shaft assembly 6.2, a main box rear cover 6.3, an oil pump 6.4, a main box upper oil pipe 6.5, and a main box lower oil pipe 6.6;

[0038] The auxiliary box motor 1 and the auxiliary box gearbox 2 form an auxiliary box sub-assembly, the main box motor 5 and the main box gearbox 6 form a main box sub-assembly, the main box sub-assembly and the auxiliary box sub-assembly are respectively located on both sides of the bridge sub-assembly 4, the main box housing 6.1 of the main box gearbox 6 and the auxiliary box housing 2.1 of the auxiliary box gearbox 2 are respectively fixed to the housing positions on both sides of the bridge sub-assembly 4 corresponding to the differential gear by bolts, the main box rear cover 6.3 is provided with a main box external oil circuit interface 6.3.1, the auxiliary box housing 2.1 is provided with an auxiliary box housing oil inlet 2.1.1, and the inter-bridge oil pipe 3 is connected to the main box external oil circuit interface 6.3. 1 and the oil inlet 2.1.1 of the auxiliary box housing, an oil filter is arranged at the bottom of the cavity of the main box gearbox 6, and the oil pump 6.4 is indirectly connected to the oil filter to pump lubricating oil. The oil pump 6.4 pumps one path of oil into the main box gearbox 6 for lubrication, and the oil pump 6.4 pumps the other path of oil into the auxiliary box gearbox 2 through the inter-bridge oil pipe 3 for lubrication. The bottoms of the cavity of the auxiliary box gearbox 2, the differential gear cavity of the axle sub-assembly 4, and the cavity of the main box gearbox 6 are connected to form a reflux area of ​​the lubricating oil, and the oil filter (not shown in the figure, belonging to the existing mature structure) is located in the inner cavity area of ​​the main box gearbox 6 in the reflux area.

[0039] During specific implementation, the interface between the oil pump 6.4 and the main box rear cover 6.3 is designed to be centrally symmetrical. The differential gear forward and reverse rotation matches the oil pump 6.4 at the 0 degree position and the oil pump 6.4 at the 180 degree position. The oil pump 6.4 has two working positions, 0 degree position and 180 degree position. When the gear is reversed, the oil pump 6.4 rotates to switch positions, so that the oil suction port and the oil outlet of the oil pump 6.4 are swapped. Through the centrally symmetrical interface structure of the oil pump 6.4 and the rear cover, when the gear is reversed, the assembly position of the oil pump 6.4 is rotated 180 degrees, which is equivalent to the differential gear forward transmission with the 0 degree oil pump assembly, and the differential gear reverse transmission with the 180 degree oil pump assembly, which meets the oil pumping needs of the electric drive axle in both front and rear driving directions.

[0040] During specific implementation, the lubrication of the oil circuit is as follows: a main box external oil circuit interface 6.3.1 is provided on the top of the main box rear cover 6.3, the lubricating oil is filtered by the oil filter, reaches the main box rear cover oil inlet channel 6.3.10, enters the oil pump oil inlet port 6.3.11 to reach the oil pump 6.4, and then is pumped out through the oil pump oil outlet port 6.3.12, and is shunted to the main box rear cover upper oil pipe oil channel 6.3.13 and the main box rear cover lower oil pipe oil channel 6.3.7; the main box rear cover lower oil pipe oil channel 6.3.7 is connected to the main box rear cover lower oil pipe oil hole 6.3.8, and the lubricating oil enters the main box lower oil pipe 6.6; the main box rear cover upper oil pipe oil channel 6.3.13 is shunted to the main box external oil circuit interface 6.3.1, the main box rear cover upper oil pipe oil inlet port 6.3.2, and the main box rear cover bearing lubrication oil channel 6.3.3;

[0041] The main box external oil circuit interface 6.3.1 is connected to the bridge oil pipe 3 so that the lubricating oil reaches the auxiliary box gearbox 2; the main box rear cover upper oil pipe oil inlet 6.3.2 is connected to the main box upper oil pipe 6.5 so that the lubricating oil reaches the main box shell upper oil pipe oil inlet 6.1.1;

[0042] The main box rear cover bearing lubricating oil passage 6.3.3 is connected to the main box input shaft bearing chamber 6.3.4, and then reaches the main box rear cover intermediate shaft bearing chamber 6.3.6 via the main box rear cover intermediate shaft oil passage 6.3.5;

[0043] The output shaft bearing chamber 6.3.9 of the rear cover of the main box is lubricated by the lubricating oil splashed down from the above lubrication and the oil channel inside the output shaft of the main box;

[0044] The lubricating oil reaching the oil inlet 6.1.1 of the main case housing passes through the main case housing input shaft oil passage 6.1.2 into the main case housing input shaft bearing chamber 6.1.3, and then enters the main case housing intermediate shaft bearing chamber 6.1.5 through the main case housing intermediate shaft oil passage 6.1.4;

[0045] The lubricating oil of the main box lower oil pipe 6.6 is connected to the main box housing lower oil pipe oil inlet 6.1.7, passes through the main box housing output shaft oil passage 6.1.8, and enters the main box output shaft oil outlet 6.1.9 to lubricate the main box housing output shaft bearing chamber 6.1.6;

[0046] The lubricating oil passes through the main box output shaft oil outlet 6.1.9, one way is through the motion gap to lubricate the main box housing output shaft bearing 6.2.1, and the other way reaches the main box output shaft inner oil passage 6.2.2; the lubricating oil entering the main box output shaft inner oil passage 6.2.2, one way is through the main box output shaft radial oil hole 6.2.5 to lubricate the needle bearing, and the other way is through the main box output shaft axial oil hole 6.2.3 to lubricate the main box rear cover output shaft bearing 6.2.4;

[0047] The lubricating oil from the inter-bridge oil pipe 3 passes through the auxiliary box housing oil inlet 2.1.1, the auxiliary box housing oil inlet passage 2.1.2, and reaches the auxiliary box oil pipe oil inlet 2.1.3, and then splits, one way connects to the auxiliary box oil pipe 2.3, and the other way reaches the auxiliary box housing input shaft bearing chamber 2.1.4 to lubricate the auxiliary box housing input shaft bearing, and then passes through the auxiliary box housing output shaft oil inlet passage 2.1.5 to reach the main box housing output shaft bearing chamber 2.1.6 to lubricate the output shaft bearing;

[0048] For a relatively closed electric drive axle gearbox housing, an oil discharge hole 2.1.7 is also provided at the bottom of the auxiliary gearbox housing 2.1, which allows the active lubrication oil to smoothly return to the axle pack;

[0049] The auxiliary box oil pipe 2.3 is connected to the auxiliary box rear cover oil inlet 2.2.1, and the lubricating oil enters the auxiliary box rear cover input shaft bearing chamber 2.2.2 to lubricate the auxiliary box rear cover input shaft bearing, and then enters the auxiliary box rear cover output shaft chamber 2.2.4 through the auxiliary box rear cover output shaft oil inlet channel 2.2.3 to lubricate the auxiliary box rear cover output shaft bearing.

[0050] The auxiliary box motor and the auxiliary box gearbox form the auxiliary box sub-assembly, the main box motor and the main box gearbox form the main box sub-assembly, the main box sub-assembly and the auxiliary box sub-assembly are respectively located on both sides of the bridge sub-assembly, which effectively utilizes the space on both sides of the bridge assembly and can make the mass distribution on both sides of the bridge even, which is convenient for the suspension design of the vehicle chassis and avoids the adverse effect of uneven mass distribution on the suspension strength of the entire electric drive bridge; and the differential gears are meshed with the gears on both sides, and the force directions at both ends are obtuse angles. The force on the differential gears during operation will be borne by the gears at both ends at the same time, and the force directions at the obtuse angles at both ends will further reduce the force on the bearings at both ends of the differential gears. The differential bearings are the end bearings, bear the largest load, and are the most prone to failure. This structure can minimize the differential The bearing load improves the overall reliability of the electric drive axle; in addition, an oil pump is only arranged in the main box gearbox, and the inter-bridge oil pipe connects the main box external oil circuit interface and the auxiliary box housing oil inlet. The oil pump pumps one oil into the main box gearbox for lubrication, and the oil pump pumps the other oil into the auxiliary box gearbox through the inter-bridge oil pipe for lubrication, which requires only the oil pump to be installed in the main box gearbox, making the lubrication structure simple and the lubrication reliability high; the oil pump realizes the need for two-way oil pumping through an assembly method in which the rotor rotates in an adaptive direction and then rotates to meet the two-way layout requirement of the bridge assembly, without the need to develop multiple housings, with high compatibility, low cost and easy distinction; and the bottom is equipped with an oil filter with high lubrication cleanliness, which overcomes the poor cleanliness of the bridge housing and reduces the adverse effects of the poor cleanliness of the bridge housing on the gear bearings of the gearbox.

[0051] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0052] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A multi-speed electric drive axle assembly structure, characterized in that: It includes: Bridge sub-assembly; Auxiliary box gearbox, which includes an auxiliary box housing, an auxiliary box rear cover, an auxiliary box oil pipe, and an auxiliary box gear shaft assembly; Auxiliary box motor; The main box gearbox includes a main box housing, a main box gear shaft assembly, a main box rear cover, an oil pump, a main box upper oil pipe, and a main box lower oil pipe; Main box motor; and inter-bridge oil pipelines; The auxiliary box motor and the auxiliary box gearbox form an auxiliary box sub-assembly, the main box motor and the main box gearbox form a main box sub-assembly, the main box sub-assembly and the auxiliary box sub-assembly are respectively located on both sides of the bridge sub-assembly, the main box housing of the main box gearbox and the auxiliary box housing of the auxiliary box gearbox are respectively fixedly connected to the housing positions on both sides of the bridge sub-assembly corresponding to the differential gear by bolts, the main box rear cover is provided with a main box external oil circuit interface, the auxiliary box housing is provided with an auxiliary box housing oil inlet, and the inter-bridge oil pipe is connected to the main box external oil circuit interface The main case gearbox is provided with an oil filter at the bottom of the cavity, and the oil pump is indirectly connected to the oil filter to pump lubricating oil. The oil pump pumps one path of oil into the main case gearbox for lubrication, and the oil pump pumps another path of oil into the auxiliary case gearbox through the inter-bridge oil pipe for lubrication. The cavity of the auxiliary case gearbox, the differential gear cavity of the axle sub-assembly, and the cavity of the main case gearbox are connected at the bottom to form a reflux area of ​​the lubricating oil, and the oil filter is located in the inner cavity area of ​​the main case gearbox in the reflux area.

2. The multi-speed electric drive axle assembly structure according to claim 1, characterized in that: The interface between the oil pump and the main box rear cover is designed to be centrally symmetrical. The differential gear forward and reverse rotation matches the 0-degree oil pump and the 180-degree oil pump. The oil pump has two working positions, 0 degree and 180 degree. When the gear is reversed, the oil pump rotates to switch positions, so that the oil suction port and the oil outlet of the oil pump are swapped. Through the centrally symmetrical interface structure of the oil pump and the rear cover, the oil pump assembly position is rotated 180 degrees when the gear is reversed, which is equivalent to the differential gear forward transmission matching the 0-degree oil pump assembly, and the differential gear reverse transmission matching the 180-degree oil pump assembly.

3. The multi-speed electric drive axle assembly structure according to claim 2 is characterized in that: The top of the main box rear cover is provided with a main box external oil circuit interface, and the main box rear cover is also provided with an upper oil pipe oil inlet of the main box rear cover and a lubricating oil channel for the main box rear cover bearing; the lubricating oil is filtered by the oil filter, reaches the main box rear cover oil inlet oil channel, enters the oil pump oil inlet to reach the oil pump, and then is pumped out through the oil pump outlet, and is divided into the upper oil pipe oil channel of the main box rear cover and the lower oil pipe oil channel of the main box rear cover; The oil channel of the oil pipe under the main box rear cover is connected to the oil hole of the oil pipe under the main box rear cover, and the lubricating oil enters the lower oil pipe of the main box; the oil channel of the oil pipe on the main box rear cover is branched to the main box external oil circuit interface, the oil pipe oil inlet on the main box rear cover, and the main box rear cover bearing lubrication oil channel; the main box external oil circuit interface is connected to the inter-bridge oil pipe so that the lubricating oil reaches the auxiliary box gearbox; the oil pipe oil inlet on the main box rear cover is connected to the main box upper oil pipe, so that the lubricating oil reaches the oil pipe oil inlet on the main box shell, the main box rear cover bearing lubrication oil channel is connected to the main box input shaft bearing chamber, and then reaches the main box rear cover intermediate shaft bearing chamber through the main box rear cover intermediate shaft oil channel. The main box rear cover output shaft bearing chamber is lubricated by the lubricating oil splashed down from the above lubrication and the oil channel inside the main box output shaft.

4. The multi-speed electric drive axle assembly structure according to claim 3 is characterized in that: The lubricating oil reaching the oil inlet of the oil pipe on the main box housing enters the input shaft bearing chamber of the main box housing through the input shaft oil passage of the main box housing, and then enters the intermediate shaft bearing chamber of the main box housing through the intermediate shaft oil passage of the main box housing.

5. The multi-speed electric drive axle assembly structure according to claim 4, characterized in that: The lubricating oil of the lower oil pipe of the main box is connected to the oil inlet of the lower oil pipe of the main box shell, passes through the output shaft oil passage of the main box shell, and enters the oil outlet of the output shaft of the main box.

6. The multi-speed electric drive axle assembly structure according to claim 5, characterized in that: The lubricating oil passes through the oil outlet of the main box output shaft, one way is to lubricate the output shaft bearing of the main box housing through the motion clearance, and the other way reaches the oil channel inside the main box output shaft; the lubricating oil entering the oil channel inside the main box output shaft passes through the radial oil hole of the main box output shaft to lubricate the needle bearing, and the other way is to lubricate the output shaft bearing of the main box rear cover through the axial oil hole of the main box output shaft.

7. The multi-speed electric drive axle assembly structure according to claim 6, characterized in that: The lubricating oil from the inter-bridge oil pipe passes through the oil inlet of the auxiliary case housing, the oil inlet channel of the auxiliary case housing reaches the oil inlet of the auxiliary case oil pipe and then splits, one path connects to the auxiliary case oil pipe, and the other path reaches the input shaft bearing chamber of the auxiliary case housing to lubricate the input shaft bearing of the auxiliary case housing, and then passes through the output shaft oil inlet channel of the auxiliary case housing to reach the output shaft bearing chamber of the main case housing to lubricate the output shaft bearing.

8. The multi-speed electric drive axle assembly structure according to claim 7, characterized in that: For the relatively closed electric drive axle gearbox housing, an oil discharge hole is also provided at the bottom of the auxiliary box housing, which allows the active lubrication oil to return smoothly to the bridge package.

9. The multi-speed electric drive axle assembly structure according to claim 7, characterized in that: The auxiliary box oil pipe is connected to the oil inlet of the auxiliary box rear cover, and the lubricating oil enters the auxiliary box rear cover input shaft bearing chamber to lubricate the auxiliary box rear cover input shaft bearing, and then enters the auxiliary box rear cover output shaft chamber through the auxiliary box rear cover output shaft oil inlet channel to lubricate the auxiliary box rear cover output shaft bearing.

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