CN113090742A

CN113090742A - Intermediate axle main reducer assembly with improved lubricating system

Info

Publication number: CN113090742A
Application number: CN202110345237.3A
Authority: CN
Inventors: 张少侠; 赵喜一; 闫萌萌; 王梅; 付祖发
Original assignee: Dongfeng Dana Axle Co Ltd
Current assignee: Dongfeng Dana Axle Co Ltd
Priority date: 2021-03-30
Filing date: 2021-03-30
Publication date: 2021-07-09

Abstract

The invention relates to a middle axle main reducer assembly with an improved lubricating system.A reducer casing is provided with an oil receiving groove corresponding to a driven bevel gear and is provided with a first oil channel, the rear end of a first rear end bearing is provided with an oil baffle plate which is hermetically connected with the reducer casing, a closed annular space is formed between the oil baffle plate and the first rear end bearing, and the first oil channel is communicated with the oil receiving groove and the annular space; subtract and still be formed with the oil storage tank on the shell, first oil trap and second oil duct, the oil storage tank is located passive roller gear's bottom, first oil trap correspondence sets up in initiative roller gear's periphery, the inner wall upper end of gear cover is formed with the oil groove of leading that extends to first front end bearing, oil groove and first oil trap are led in the second oil duct intercommunication, the lower extreme of gear cover is equipped with second oil trap and third oil duct, the one end and the second oil trap intercommunication of third oil duct, the other end extends to second front end bearing top. The system can fully lubricate the gear and the bearing during the running of the automobile, and prolongs the service life of the main reducer assembly of the intermediate axle.

Description

Intermediate axle main reducer assembly with improved lubricating system

Technical Field

The invention relates to the technical field of automobile drive axles, in particular to a middle axle main reducer assembly with an improved lubricating system.

Background

At present, in the field of automobile drive axles, in a main speed reducer assembly of a middle axle, a main shaft transmits kinetic energy of an engine to a rear axle through an inter-axle differential, and meanwhile, the main shaft and a driving bevel gear are meshed with each other through a pair of cylindrical gears to synchronously transmit the kinetic energy to the inter-wheel differential of the middle axle and then to wheels to drive a vehicle to move forwards. The main shaft, the interaxle differential and the drive bevel gear are all installed in the reducer casing through various bearings. Because the transmission part is more and comparatively dispersed, there is the problem that lubricating oil can not fully lubricate gear and bearing in traditional well bridge main reducer assembly, leads to gear and bearing premature failure, reduces lubricated efficiency etc..

Disclosure of Invention

The invention provides a middle axle main reducer assembly with an improved lubricating system aiming at the technical problems in the prior art, and aims to solve the problem that the lubricating effect of the conventional reducer assembly is poor.

The technical scheme for solving the technical problems is as follows:

a middle axle main reducer assembly with an improved lubricating system comprises a reduction shell, a gear cover, a main shaft, an inter-axle differential, a driving cylindrical gear and a driven cylindrical gear, wherein the reduction shell and the gear cover are connected with each other; the driving cylindrical gear and the inter-axle differential are sequentially arranged on the main shaft from front to back, a first front end bearing is arranged at the front end of the driving cylindrical gear, the first front end bearing is limited in the reducer casing through a gear cover, and a first rear end bearing is arranged at the rear end of the inter-axle differential; two ends of the driven cylindrical gear are respectively installed on the reducer casing through a second front end bearing and a second rear end bearing, a driving bevel gear is installed at the rear end of the driven cylindrical gear, a driven bevel gear is fixedly arranged on the inter-wheel differential, and the driving bevel gear is in meshing transmission with the driven bevel gear;

an oil receiving groove is formed in the reducer casing corresponding to the driven bevel gear, a first oil duct is formed in the reducer casing, an oil baffle plate which is connected to the reducer casing in a sealing mode is installed at the rear end of the first rear end bearing, a closed annular space is formed between the oil baffle plate and the first rear end bearing, and the first oil duct is communicated with the oil receiving groove and the annular space;

the oil reducing shell is further provided with an oil storage groove, a first oil collecting groove and a second oil duct, the oil storage groove is located at the bottom of the driven cylindrical gear, the first oil collecting groove is correspondingly arranged on the periphery of the driving cylindrical gear, an oil guide groove extending to the first front end bearing is formed in the upper end of the inner wall of the gear cover, the second oil duct is communicated with the oil guide groove and the first oil collecting groove, the lower end of the gear cover is provided with the second oil collecting groove and a third oil duct, and one end of the third oil duct is communicated with the second oil collecting groove while the other end of the third oil duct extends to the position above the second front end bearing.

Preferably, an oil slinger is further arranged on an opening of the differential case facing the second rear end bearing, the oil slinger is coaxially arranged with the second rear end bearing, one end of the oil slinger is hermetically connected with an outer ring of the second rear end bearing through the reducer casing, and the other end of the oil slinger is hermetically connected with an end portion of the differential case.

Preferably, the inner wall of the reduction housing is matched with the interaxle differential, the driving cylindrical gear and the driven cylindrical gear.

Preferably, the inter-axle differential comprises a differential housing, and a cross shaft, a planetary gear and a rear half-shaft bevel gear which are arranged in the differential housing, wherein the rear half-shaft bevel gear is coaxially arranged with the main shaft, the end part of the main shaft penetrates through the axle center of the cross shaft and extends into the end part of the rear half-shaft bevel gear, the main shaft is in key connection with the cross shaft, and the end part of the main shaft is in rotary fit with the end part of the rear half-shaft bevel gear; four shaft necks of the cross shaft are all perpendicular to the main shaft, the planetary gear is mounted on each shaft neck of the cross shaft, the planetary gears can rotate, and the rear half shaft bevel gear is meshed with all the planetary gears; the side surface of the driving cylindrical gear facing the cross shaft is provided with a bevel gear surface, and the bevel gear surface is meshed with the planetary gear.

Preferably, the periphery of the end part of the main shaft is provided with a bushing, and the end part of the main shaft is in running fit with the end part of the rear half-shaft bevel gear through the bushing.

Preferably, the driving cylindrical gear is connected with the main shaft through a spline.

Preferably, the driven cylindrical gear is connected with the gear shaft through a spline.

Preferably, the gear cover is disposed above the second front end bearing.

The invention has the beneficial effects that: the oil path of the lubricating system is as follows: in the running process of a vehicle, the driven bevel gear rotates to throw lubricating oil into the oil receiving groove, the lubricating oil enters the annular space through the first oil duct, along with the rotation of the inter-axle differential mechanism, the lubricating oil enters the inter-axle differential mechanism after passing through the first rear end bearing, flows out from an opening at the other end of the inter-axle differential mechanism and flows to the oil storage groove through the second rear end bearing; the driven cylindrical gear is in meshing transmission with the driving cylindrical gear, and lubricating oil is thrown to the first oil collecting tank; and the lubricating oil flows to the oil guide groove of the gear cover through the second oil duct and flows to the first front end bearing, and the lubricating oil continues to be collected downwards by the second oil collecting groove and finally flows to the second front end bearing through the third oil duct. This improve lubricating system's intermediate axle main reducer assembly has realized lubricating all drive disk assembly's transmission parts, can fully lubricate gear and bearing in the car operation is automatic, and is lubricated effectual, has improved the life of intermediate axle main reducer assembly.

Drawings

FIG. 1 is a first cross-sectional view from a primary perspective of the present invention;

FIG. 2 is a second cross-sectional view from the primary perspective of the present invention;

FIG. 3 is a top cross-sectional view of the present invention;

FIG. 4 is a schematic view of the internal structure of the present invention with the casing removed;

FIG. 5 is a schematic view of the shell reduction structure of the present invention;

FIG. 6 is a schematic view of a slinger configuration of the present invention;

FIG. 7 is a schematic view of the gear cover structure of the present invention.

In the drawings, the components represented by the respective reference numerals are listed below:

1. the oil reducing housing comprises a shell reducing body 101, an oil receiving groove 102, a first oil passage 103, an oil baffle plate 104, an oil baffle ring 105, a first oil collecting groove 106, a second oil passage 2, an interaxial differential 201, a rear half shaft bevel gear 202, a cross shaft 203, a planetary gear 204, a bushing 205, a differential housing 3, a main shaft 4, a driving cylindrical gear 401, a bevel gear surface 5, a first rear end bearing 6, a first front end bearing 7, a gear shaft 8, a driven cylindrical gear 9, a driving conical gear 10, a second front end bearing 11, a second rear end bearing 12, a gear cover 1201, an oil guide groove 1202, a second oil collecting groove 1203, a third oil passage 13, an interaxle differential 1301, a driven bevel gear, an a ring space b and an oil storage groove.

Detailed Description

The principles and features of this invention are described below in conjunction with the following drawings, which are set forth by way of illustration only and are not intended to limit the scope of the invention.

As shown in fig. 1 to 7, a main reducer assembly of a middle axle with an improved lubrication system comprises a reducer casing 1, a gear cover 12, a main shaft 3, an inter-axle differential 2, a driving cylindrical gear 4 and a driven cylindrical gear 8 which are connected with each other and arranged between the reducer casing 1 and the gear cover 12, and an inter-wheel differential 13 arranged outside the reducer casing 1; the driving cylindrical gear 4 and the inter-axle differential 2 are sequentially mounted on the main shaft 3 from front to back, a first front end bearing 6 is arranged at the front end of the driving cylindrical gear 4, the first front end bearing 6 is limited in the reducer casing 1 through a gear cover 12, and a first rear end bearing 5 is arranged at the rear end of the inter-axle differential 2; two ends of the driven cylindrical gear 8 are respectively installed on the reducer casing 1 through a second front end bearing 10 and a second rear end bearing 11, the rear end of the driven cylindrical gear 8 is provided with a driving bevel gear 9, the inter-wheel differential 13 is fixedly provided with a driven bevel gear 1301, and the driving bevel gear 9 is in meshing transmission with the driven bevel gear 1301;

an oil receiving groove 101 is formed in the reduction casing 1 corresponding to the driven bevel gear 1301, a first oil channel 102 is formed in the reduction casing, an oil baffle plate 103 which is connected to the reduction casing 1 in a sealing mode is installed at the rear end of the first rear end bearing 5, a closed annular space a is formed between the oil baffle plate 103 and the first rear end bearing 5, and the first oil channel 102 is communicated with the oil receiving groove 101 and the annular space a;

an oil storage groove b, a first oil collecting groove 105 and a second oil duct 106 are further formed in the reducer casing 1, the oil storage groove b is located at the bottom of the driven cylindrical gear 8, the first oil collecting groove 105 is correspondingly arranged on the periphery of the driving cylindrical gear 4, an oil guide groove 1201 extending to the first front end bearing 6 is formed in the upper end of the inner wall of the gear cover 12, the second oil duct 106 is communicated with the oil guide groove 1201 and the first oil collecting groove 105, a second oil collecting groove 1202 and a third oil duct 1203 are arranged at the lower end of the gear cover 12, one end of the third oil duct 1203 is communicated with the second oil collecting groove 1202, and the other end of the third oil duct 1203 extends to the position above the second front end bearing 10.

More specifically, in the intermediate axle main reducer assembly, the inter-axle differential 2, the driving cylindrical gear 4 and the first front end bearing 6 are sequentially coaxially sleeved on the main shaft 3, one end of the inter-axle differential 2 is in transmission connection with one end of the main shaft 3, and the other end of the main shaft 3 penetrates through the reducer casing 1. The other end of the inter-axle differential 2 is a rear half-axle bevel gear 201 extending out of the housing of the inter-axle differential 2. First rear end bearing 5 cover is established on back half axle bevel gear 201, just first rear end bearing 5 is close to differential 2's between the axle shell sets up, and first rear end bearing 5, subtract shell and differential 2's between the axle shell mutually support and form the oily passageway of crossing of lubricating oil. The shaft hole of the driving cylindrical gear 4 is connected with the periphery of the main shaft 3 through a spline, and the driving cylindrical gear 4 can rotate at the same speed with the main shaft 3. The main shaft 3 penetrates through a gear cover 12, the gear cover 12 is fixedly connected with the reduction shell 1 and is abutted to the first front end bearing 6, and the first front end bearing 6 is limited on the reduction shell 1. Specifically, the gear cover 12 is provided with a stepped hole coaxial with the first front end bearing 6, the first front end bearing 6 is embedded into the stepped hole, and the outer ring of the first front end bearing 6 is tightly abutted to the gear cover 12. The main shaft 3 is provided with an annular step, and one side of the annular step, which is far away from the gear cover 12, on the first front end bearing 6 is tightly abutted against the inner ring of the first front end bearing 6 so as to axially limit the first front end bearing 6.

A gear shaft 7 is arranged on the driven cylindrical gear 8, and the gear shaft 7 is arranged below the main shaft 3 in parallel. The second rear end bearing 11, the driven cylindrical gear 8 and the second front end bearing 10 are sequentially coaxially sleeved on the periphery of the gear shaft 7. The shaft hole of the driven cylindrical gear 8 is connected with the peripheral key of the gear shaft 7 through a spline, so that the driven cylindrical gear 8 and the gear shaft 7 can rotate at the same speed. The rear end of the gear shaft 7 penetrates through the reduction shell 1, and the end part of the gear shaft 7 extending out of the reduction shell 1 is coaxially and fixedly connected with the driving bevel gear 9. The inter-wheel differential 13 is connected to the housing 1 so as to be rotatable relative thereto via a flange extending from the housing 1. A driven bevel gear 1301 is fixedly arranged on a shell of the inter-wheel differential 13, the driving bevel gear 9 is meshed with the driven bevel gear 1301, and when the driving bevel gear 9 rotates, the inter-wheel differential 13 is driven to rotate.

One end of the inter-axle differential 2, which is opposite to the main shaft 3, penetrates through the reduction casing 1, namely, an opening is formed in the position, close to the rear half-axle bevel gear 201, of the reduction casing 1. The oil receiving groove 101 is formed in the inner wall of the opening of the reduction case 1, and the oil receiving groove 101 is disposed toward the driven bevel gear 1301 of the inter-wheel differential 13. The shell reducing 1 is also provided with a first oil passage 102 communicated with the oil receiving groove 101. The shape of the reduction shell 1 is matched with that of the rear half-axis bevel gear 201. Subtract and still be equipped with oil baffle 103 on the shell 1, back half shaft bevel gear 201 runs through oil baffle 103, oil baffle 103 subtract shell 1 with first rear end bearing 5 mutually supports and forms inclosed annular space an, first oil duct 102 intercommunication connect oil groove 101 with annular space a. Lubricating oil is applied to the driven bevel gear 1301 of the inter-wheel differential 13, the driven bevel gear 1301 throws the lubricating oil into the oil receiving groove 101 in the inner wall of the reduction housing 1 when rotating at a high speed, and the lubricating oil flows into the annular space a between the oil baffle 103 and the first rear end bearing 5 through the first oil passage 102. When the lubricant oil accumulates in the annular space a and the liquid level rises to a certain height, the lubricant oil lubricates the first rear end bearing 5 through a fit clearance between the inner ring and the outer ring of the first rear end bearing 5. Meanwhile, as the rear half shaft bevel gear 201 rotates, lubricating oil is brought into the inter-axle differential 2 to lubricate each transmission part inside the inter-axle differential 2, and redundant lubricating oil flows out through an opening formed by matching the shell of the inter-axle differential 2 and the main shaft 3.

The shape of the inner wall of the reducing shell 1 is matched with the driving cylindrical gear 4 and the driven cylindrical gear 8, and an oil storage tank b is formed at the bottom of the driven cylindrical gear 8. After flowing out of the outer case of the inter-axle differential 2, the lubricating oil flows down along the inner wall of the reduction case 1 and gradually accumulates in the oil reservoir b at the bottom of the driven spur gear 8. During the downward flow of the lubricating oil along the inner wall of the reduction housing 1, the lubricating oil passes through the second rear end bearing 11 on the gear shaft 7 and lubricates it. The bottom of the driven cylindrical gear 8 is soaked in lubricating oil, and when the driven cylindrical gear 8 rotates at a high speed, the lubricating oil is driven to the driving cylindrical gear 4 to lubricate the driving cylindrical gear; then, the driving cylindrical gear 4 throws out the lubricating oil onto the reduction housing 1 in the circumferential direction thereof in the process of high-speed rotation.

As shown in fig. 1 and 5, a first oil collecting groove 105 is formed in the periphery of the reducer casing 1, which is close to the driving cylindrical gear 4, one or more first oil collecting grooves 105 may be provided, an oil blocking sheet for blocking lubricating oil from flowing downward is provided on an edge of each first oil collecting groove 105, and a second oil passage 106 is provided in the first oil collecting groove 105. An oil guide groove 1201 is formed in the upper end of the inner wall of the gear cover 12, the second oil duct 106 is communicated with the first oil collecting groove 105 and the oil guide groove 1201, and the oil guide groove 1201 extends to the first front end bearing 6. The driving cylindrical gear 4 throws the lubricating oil out of the first oil collecting groove 105 on the reducer casing 1, and the lubricating oil collected in the first oil collecting groove 105 flows to the oil guide groove 1201 on the gear cover 12 through the second oil passage 106 and flows down to the first front end bearing 6 along the oil guide groove 1201 to lubricate the first front end bearing 6 on the main shaft 3.

As shown in fig. 1, 3 and 7, the gear cover 12 is disposed above the second front end bearing 10. A second oil collecting groove 1202 is formed in the lower end of the inner wall of the gear cover 12, an oil blocking piece for blocking lubricating oil from flowing out is arranged on the edge of the second oil collecting groove 1202, a third oil duct 1203 is arranged in the second oil collecting groove 1202, and the third oil duct 1203 extends to the position above the second front end bearing 10. After the lubricating oil on the gear cover 12 lubricates the first front end bearing 6, the excess lubricating oil flows down along the inner wall of the gear cover 12, is collected by the second oil sump 1202, is guided to the inner wall of the reduction casing 1 above the second front end bearing 10 through the third oil passage 1203, and flows down along the reduction casing 1 onto the second front end bearing 10 to lubricate the second front end bearing.

In the present embodiment, as shown in fig. 1 and 6, an oil slinger 104 is further provided in an opening of the differential case 205 facing the first rear end bearing 5, the oil slinger 104 is provided coaxially with the first rear end bearing 5, one end of the oil slinger 104 is hermetically connected to the outer ring of the first rear end bearing 5 through the reducer case 1, and the other end of the oil slinger 104 is hermetically connected to an end portion of the differential case 205. The oil slinger 104 is arranged to play a role in sealing between the differential case 205 and the first rear end bearing 5, so that lubricating oil is prevented from flowing down through a gap between the differential case 205 and the first rear end bearing 5, the amount of lubricating oil entering the inter-axle differential 2 is reduced, and the lubricating effect is reduced; secondly, the oil deflector ring 104 plays a guiding role, and the oil deflector ring 104 is equivalent to a pipeline, so that the lubricating oil directly flows into the differential case 205 through the oil deflector ring 104 after flowing out of the first rear end bearing 5, and lubricates all transmission parts inside the inter-axle differential 2.

In this embodiment, the inter-axle differential 2 includes a differential case 205, and a spider 202, a planetary gear 203, and a rear half-axle bevel gear 201 that are disposed in the differential case 205, the rear half-axle bevel gear 201 is disposed coaxially with the main shaft 3, an end of the main shaft 3 penetrates through an axis of the spider 202 and extends into an end of the rear half-axle bevel gear 201, the main shaft 3 is in key connection with the spider 202, and an end of the main shaft 3 is in rotational fit with an end of the rear half-axle bevel gear 201; four shaft necks of the cross shaft 202 are all arranged perpendicular to the main shaft 3, the planetary gear 203 is mounted on each shaft neck of the cross shaft 202, each planetary gear 203 can rotate, and the rear half shaft bevel gear 201 is meshed with all the planetary gears 203; the side of the driving spur gear 4 facing the cross 202 is a bevel gear surface 401, and the bevel gear surface 401 is engaged with all the planet gears 203.

The main shaft 3 serves as both a transmission member and a support member of the inter-axle differential 2. When the main shaft 3 rotates, the cross shaft 202 is driven to revolve, the planet gear 203 on the cross shaft 202 is meshed with the rear half shaft bevel gear 201 to drive the rear half shaft bevel gear 201 to rotate, and the rear half shaft bevel gear 201 is connected with a driving shaft of a rear axle through a spline and is driven at the same speed. The bevel gear surface 401 on the main shaft 3 and the bevel gear 201 on the rear half shaft are respectively meshed with the planet gears 203, when the planet gears 203 rotate, the differential speed between the shafts is realized, and the differential speed running between the middle axle and the rear axle is realized. When the lubricating oil enters the differential case 205 from the end of the inter-shaft differential 2 close to the rear half shaft bevel gear 201, the four planetary gears 203 can be lubricated all together due to the meshing of the rear half shaft bevel gear 201 with the planetary gears 203 and the revolution of the planetary gears 203; since the planetary gears 203 are engaged with the bevel gear surface 401 on the side of the cylindrical gear on the main shaft 3, the bevel gear surface 401 on the side of the cylindrical gear can be lubricated. The excess lubricating oil flows out from the opening of the differential case 205 near the main shaft 3.

In this embodiment, a bushing 204 is disposed on the outer periphery of the end of the main shaft 3 extending into the rear half shaft, and the end of the main shaft 3 is rotatably fitted with the end of the rear half shaft bevel gear 201 through the bushing 204. The main shaft 3 supports the rear half shaft gear through the bushing 204, so that the supporting rigidity of the interaxle differential 2 is increased, and meanwhile, the main shaft 3 supports the cross shaft 202, so that the meshing reliability of the rear half shaft bevel gear 201 and the planetary gears 203 on the cross shaft 202 is enhanced. The lubricating oil flows from the end of the rear half bevel gear 201 to the end of the main shaft 3 and the bushing 204, and lubricates them.

The working principle is as follows:

in the running process of the vehicle, the main shaft 3 transmits the torque of an engine to the main speed reducer assembly, and the kinetic energy is transmitted to the driving bevel gear 9 by the engagement of the driving cylindrical gear 4 and the driven cylindrical gear 8; the drive bevel gear 9 meshes with a driven bevel gear 1301 on the housing of the inter-wheel differential 13, thereby transferring kinetic energy to the wheels on both sides of the intermediate axle through the inter-wheel differential 13. Lubricating oil is applied to a driven bevel gear 1301 on the inter-wheel differential 13, the driven bevel gear 1301 throws the lubricating oil into an oil receiving groove 101 on the reduction casing 1 when rotating at a high speed, the lubricating oil flows into an annular space a on the other surface of the oil baffle plate 103 through a first oil passage 102 in the oil receiving groove 101, and the lubricating oil lubricates a first rear end bearing 5 when the lubricating oil in the annular space a is accumulated to a high liquid level; when the rear half shaft bevel gear 201 runs, the lubricating oil is driven to enter the oil retainer ring 104 and the inter-axle differential 2, the transmission part in the inter-axle differential 2 is lubricated, and then the redundant lubricating oil flows out from the opening at the other end of the shell of the inter-axle differential 2 until the lubricating oil flows into an oil storage tank b below the driven cylindrical gear 8; in the process that the lubricating oil flows downwards to the oil storage tank b, the lubricating oil passes through the rear gear of the driving bevel gear 9 and lubricates the rear gear; when the driven cylindrical gear 8 runs, the lubricating oil in the oil storage tank b is driven to the driving cylindrical gear 4, when the driving cylindrical gear 4 runs, the lubricating oil is thrown out into the first oil collection tank 105 on the circumferential reduction shell 1, the second oil duct 106 in the first oil collection tank 105 guides the lubricating oil into the oil guide tank 1201 on the inner wall of the gear cover 12, the lubricating oil flows to the first front end bearing 6 in the oil guide tank 1201 and lubricates the first front end bearing, then the redundant lubricating oil in the oil guide tank 1201 is gathered into the second oil collection tank 1202 at the lower end of the gear cover 12, flows onto the reduction shell 1 above the second front end bearing 10 through the third oil duct 1203 in the second oil collection tank 1202, continues to flow downwards along the reduction shell 1, flows onto the second front end bearing 10 and lubricates the second front end bearing, and accordingly, all transmission parts of the main reducing gear assembly of the intermediate axle are lubricated. The system has the advantages that the gear and the bearing of the intermediate axle main reducer assembly are sufficiently lubricated, the lubricating effect is good, and the service life of the intermediate axle main reducer assembly is prolonged.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A middle axle main speed reducer assembly with an improved lubricating system is characterized in that,

the differential mechanism comprises a reducer casing, a gear cover, a main shaft, an inter-shaft differential mechanism, a driving cylindrical gear and a driven cylindrical gear, wherein the reducer casing and the gear cover are connected with each other; the driving cylindrical gear and the inter-axle differential are sequentially arranged on the main shaft from front to back, a first front end bearing is arranged at the front end of the driving cylindrical gear, the first front end bearing is limited in the reducer casing through a gear cover, and a first rear end bearing is arranged at the rear end of the inter-axle differential; two ends of the driven cylindrical gear are respectively installed on the reducer casing through a second front end bearing and a second rear end bearing, a driving bevel gear is installed at the rear end of the driven cylindrical gear, a driven bevel gear is fixedly arranged on the inter-wheel differential, and the driving bevel gear is in meshing transmission with the driven bevel gear;

2. An intermediate axle final drive assembly with an improved lubrication system according to claim 1, wherein an oil slinger is further provided on an opening of the housing of the inter-axle differential toward the first rear end bearing, the oil slinger is coaxially arranged with the first rear end bearing, one end of the oil slinger is hermetically connected with an outer ring of the first rear end bearing through the reduction case, and the other end of the oil slinger is hermetically connected with an end of the inter-axle differential.

3. An intermediate axle final drive assembly with improved lubrication system according to claim 1, wherein the inner wall of the reduction housing is fitted with the inter-axle differential, the driving cylindrical gear and the driven cylindrical gear.

4. The intermediate axle final drive assembly with an improved lubrication system according to claim 1, wherein the interaxle differential includes a differential case, and a cross shaft, a planetary gear and a rear half shaft bevel gear disposed in the differential case, the rear half shaft bevel gear is disposed coaxially with the main shaft, an end of the main shaft penetrates through an axis of the cross shaft and extends into an end of the rear half shaft bevel gear, the main shaft is keyed with the cross shaft, and an end of the main shaft is rotationally engaged with an end of the rear half shaft bevel gear; four shaft necks of the cross shaft are all perpendicular to the main shaft, the planetary gear is mounted on each shaft neck of the cross shaft, the planetary gears can rotate, and the rear half shaft bevel gear is meshed with all the planetary gears; the side surface of the driving cylindrical gear facing the cross shaft is provided with a bevel gear surface, and the bevel gear surface is meshed with the planetary gear.

5. An intermediate axle final drive assembly with an improved lubrication system according to claim 4, wherein a bushing is provided around the end of the main shaft, and the end of the main shaft is rotatably engaged with the end of the rear half shaft bevel gear through the bushing.

6. An intermediate axle final drive assembly with improved lubrication system according to claim 1, wherein the drive spur gear is splined to the main shaft.

7. An intermediate axle final drive assembly with improved lubrication system according to claim 1, wherein said driven cylindrical gear is splined to said gear shaft.

8. An intermediate axle final drive assembly with an improved lubrication system according to claim 1, wherein the gear cover is disposed above the second front end bearing.