CN118582528A - Drive axle side cover and vehicle - Google Patents

Abstract

The present application relates to the technical field of drive axles, and provides a side cover of a drive axle and a vehicle, wherein the side cover is provided with a through hole, and the side cover is also provided with a first oil baffle plate, the first oil baffle plate extends radially inwardly along the hole wall of the through hole, and the side cover is provided with an exhaust channel for installing a vent plug, and the inlet of the exhaust channel is arranged on the first oil baffle plate and faces away from the differential bearing. Through the technical solution of the present application, the problem of lubricating oil leakage can be reduced without changing the structure of the vent plug, thereby reducing production costs.

Description

Drive axle side cover and vehicle

Technical Field

The present application relates to the technical field of drive axles, and in particular to a side cover of a drive axle and a vehicle.

Background Art

When the vehicle's transmission assembly is running under high load or high speed for a short period of time, the friction and heat generated by the transmission components will cause thermal expansion of the internal gas, resulting in an internal and external pressure difference; at the same time, it is necessary to ensure that the condensed liquid or mist water vapor generated when the temperature drops suddenly cannot pass through, so the transmission assembly is required to meet the waterproof and breathable functions. Therefore, for the transmission assembly, a ventilation device, such as a vent plug, will be installed on the shell to discharge the high-pressure gas inside the shell in time to avoid oil leakage at the oil seal and the joint surface of the shell caused by high pressure, so as to achieve air pressure balance between the transmission assembly and the outside world and waterproof and dustproof performance.

The vent plug generally ensures normal ventilation function and also ensures that the lubricating oil cannot leak to the outside through the vent plug. Therefore, it is necessary to make some structural improvements to the vent plug to prevent the lubricating oil from leaking. However, directly making some structural improvements to the vent plug will increase the cost.

Summary of the invention

The technical problem to be solved by the present application is to provide a side cover of a drive axle and a vehicle, which can reduce the problem of lubricating oil leakage without changing the structure of the vent plug, thereby reducing production costs.

In order to solve the above technical problems, this application adopts the following technical solutions:

In a first aspect, the present application provides a side cover of a drive axle, wherein the side cover is provided with a through hole, and the side cover is further provided with a first oil baffle plate, wherein the first oil baffle plate extends radially inwardly along the hole wall of the through hole, and the side cover is provided with an exhaust channel for installing a vent plug, and the inlet of the exhaust channel is arranged on the first oil baffle plate and faces away from the differential bearing.

As an implementation manner, in the projection in the same horizontal direction, the projection of the first oil baffle plate toward the direction of the differential bearing covers the projection of the retaining frame of the differential bearing.

As an implementation manner, the first oil baffle is located in the upper half of the through hole.

As an implementation manner, two sides of the first oil baffle plate are used to abut against the differential bearing and the output oil seal respectively.

As an embodiment, an oil drain chamber is provided on a side of the first oil baffle away from the differential bearing, and the oil drain chamber is in the shape of an elongated strip, wherein a first end is connected to the exhaust passage, and a second end is lower in vertical height than the first end.

As an embodiment, the peripheral wall of the oil drain chamber which is closest to the center of the side cover extends obliquely downward.

As an embodiment, the axis of the exhaust passage is arranged at an angle to a vertical line perpendicular to the bottom wall of the oil drain chamber.

As an implementation manner, the exhaust passage includes a plurality of connecting sections, and the diameters of the plurality of connecting sections are different.

As an implementation manner, two adjacent connecting segments are connected via a transition curved surface.

As an embodiment, the side cover is provided with a recessed area on the side facing the differential bearing, and a protruding second oil baffle is provided in the recessed area, and the extended edge of the second oil baffle is adapted to the driven bevel gear and the differential housing, and the second oil baffle is clearance-matched with the driven bevel gear and the differential housing.

As an implementation manner, the opening of the recessed area faces the differential bearing, and the second oil baffle is located above the differential bearing.

In a second aspect, the present application provides a vehicle, comprising the side cover of the drive axle provided in the first aspect.

The technical solution of this application has the following beneficial effects:

A through hole is provided on the side cover, and a differential bearing is provided on one side of the through hole. A first oil baffle plate extending inwardly in a radial direction is provided on the hole wall of the through hole. By setting the first oil baffle plate, the lubricating oil thrown out by the differential bearing during rotation can be stopped. An exhaust channel is installed on the side cover, and the exhaust channel is used to install a breather plug. When the breather plug in the exhaust channel is depressurized, the high-pressure hot air in the drive axle will be discharged from the exhaust channel. Therefore, the side of the first oil baffle plate will directly stop a part of the oil mist, and the entrance of the exhaust channel is facing away from the differential bearing. Even if a small part of the oil mist can enter the exhaust channel, it needs to cross the first oil baffle plate to enter. Therefore, the first oil baffle plate increases the movement path of the oil mist into the exhaust channel, thereby reducing the problem of lubricating oil leakage when the breather plug is depressurized. In addition, the embodiment of the present application only needs to add the first oil baffle plate to the side cover, which can reduce costs compared to directly making structural improvements to the breather plug.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of the structure of a drive axle provided in an embodiment of the present application;

FIG2 is a schematic diagram of the structure of a side cover provided in an embodiment of the present application;

FIG3 is a schematic structural diagram of a drive axle provided in an embodiment of the present application from another perspective;

Fig. 4 is a schematic cross-sectional view of the structure along the line A-A in Fig. 3;

Fig. 5 is a schematic cross-sectional view of the structure along line B-B in Fig. 3;

FIG6 is a schematic diagram of the structure of a side cover from different viewing angles provided in an embodiment of the present application;

FIG7 is a schematic diagram of a partial explosion structure of a drive axle provided in an embodiment of the present application;

FIG. 8 is a schematic diagram of a partial structure of a drive axle provided in an embodiment of the present application.

Icons: 1-side cover; 11-through hole; 12-first oil baffle; 13-exhaust channel; 131-connecting section; 132-transition curved surface; 14-boss; 15-oil drain chamber; 16-recessed area; 17-second oil baffle; 2-differential bearing; 3-output oil seal; 4-driven bevel gear; 5-differential housing; 51-oil stirring part; 511-first side wall; 512-second side wall; 6-drive axle housing.

DETAILED DESCRIPTION

The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

As shown in Figures 2 and 6, on the first aspect, an embodiment of the present application provides a side cover 1 of a drive axle pair, the side cover 1 is provided with an exhaust passage 13, and a vent plug is installed in the exhaust passage 13. When the vent plug is in pressure relief, the side cover 1 can reduce the oil mist from entering the exhaust passage 13, so that the vent plug can reduce the leakage of lubricating oil when the pressure is relieved. The embodiment of the present application makes some structural improvements directly on the side cover 1, and there is no need to make structural improvements on the vent plug, thereby reducing production costs.

As shown in Figs. 1 to 4, a through hole 11 is provided on the side cover 1, and the differential bearing 2 and the output oil seal 3 are respectively located on both sides of the through hole 11, and the differential bearing 2 and the output oil seal 3 are both interference fit with the side cover 1. A first oil baffle 12 is provided on the side cover 1, and the first oil baffle 12 extends inwardly along the radial direction of the side cover 1 at the hole wall of the through hole 11, so that the first oil baffle 12 separates the differential bearing 2 and the output oil seal 3, and can stop the lubricating oil thrown out by the differential bearing 2 when rotating. An exhaust channel 13 is also provided on the side cover 1, and the inlet of the exhaust channel 13 faces away from the differential bearing 2. When the vent plug in the exhaust channel 13 is depressurized, the high-pressure hot air in the drive axle will be discharged from the exhaust channel 13, and some oil mist will be taken away during the discharge process. Therefore, the side of the first oil baffle 12 The surface will directly stop a part of the oil mist, and the entrance of the exhaust passage 13 is facing away from the differential bearing 2. Even if a small amount of oil mist can enter the exhaust passage 13, it needs to pass over the first oil baffle plate 12 along the axial direction of the side cover 1 before entering. Therefore, the first oil baffle plate 12 increases the movement path of the oil mist into the exhaust passage 13, reduces the oil mist entering the exhaust passage 13, and thus reduces the problem of lubricating oil leakage when the vent plug is depressurized. In addition, the embodiment of the present application only needs to add the first oil baffle plate 12 to the side cover 1, which can reduce costs compared to directly making structural improvements to the vent plug.

Optionally, the first oil baffle 12 can be directly formed during the casting process of the side cover 1, which can reduce production costs.

Optionally, the differential bearing 2 is a right bearing of the differential.

Optionally, the thickness of the first oil baffle plate 12 may be increased along the axial direction of the side cover 1 to extend the moving path of the oil mist and reduce the problem of the oil mist entering the exhaust passage 13 .

Optionally, the opening of the exhaust passage 13 may be arranged vertically upward, or may be arranged inclined upward.

Optionally, the circumferential length of the first oil baffle 12 satisfies the maximum distance of oil splashing from the differential bearing 2 when the vehicle is moving forward and reverse, thereby reducing the oil mist entering the exhaust passage 13 when the vehicle is moving forward and reverse.

As an embodiment, in the projection in the same horizontal direction, the projection of the first oil baffle plate 12 toward the differential bearing 2 covers the projection of the retaining frame of the differential bearing 2. Because the retaining frame generally does the oil throwing during the oil throwing process of the differential bearing 2, and the projection of the first oil baffle plate 12 toward the differential bearing 2 covers the projection of the retaining frame of the differential bearing 2. The extension width of the first oil baffle plate 12 in the radial direction is greater than the radial thickness of the retaining frame of the differential bearing 2. In this way, when the retaining frame throws oil, the oil is blocked by the first oil baffle portion, thereby reducing the oil from being brought into the exhaust channel 13 during the pressure relief process.

Optionally, the general differential bearing 2 is a tapered bearing, so the retaining frame is generally prism-shaped, and the projection of the first oil retaining portion toward the differential bearing 2 should cover the minimum circumferential area of the retaining frame, thereby being able to stop the lubricating oil.

As shown in FIG. 2 , as an embodiment, the first oil baffle 12 is located in the upper half of the through hole 11, so the lower half of the through hole 11 is an oil pool, and the differential bearing 2 cannot throw oil in the oil pool. The differential bearing 2 generally starts to throw oil only after exceeding the liquid level of the oil pool. The first oil baffle 12 is located in the upper half of the through hole 11 to prevent the problem of oil throwing.

As shown in FIG4 , as an embodiment, the two sides of the first oil baffle plate 12 are respectively used to abut against the differential bearing 2 and the output oil seal 3. The differential bearing 2 and the output oil seal 3 are respectively located on the two sides of the through hole 11 and are connected to the side cover 1 by interference fit. The first oil baffle plate 12 can separate the differential bearing 2 and the output oil seal 3 and can limit the differential bearing 2 and the output oil seal 3 in the axial direction. At the same time, the first oil baffle plate 12 is arranged between the differential bearing 2 and the output oil seal 3 to mainly stop the oil thrown out by the retaining frame of the differential bearing 2. The oil thrown out by the retaining frame is a small amount, thereby further reducing the oil mist from entering the exhaust passage 13. Therefore, the first oil baffle plate 12 of the embodiment of the present application is arranged at a position on the side cover 1 where there is a small amount of lubricating oil. By directly casting the structure of the first oil baffle plate 12 during the casting process, the oil thrown out by the differential bearing 2 is reduced from entering the exhaust passage 13.

As shown in FIG. 2 , optionally, a boss 14 is further provided on the hole wall of the through hole 11 , and the boss 14 is connected to the first oil baffle plate 12 , and the width of the boss 14 extending radially along the side cover 1 is smaller than that of the first oil baffle plate 12 , thereby reducing material consumption and reducing the weight of the side cover 1 .

Optionally, the differential bearing 2 and the output oil seal 3 are both in contact with the boss 14 , thereby increasing the axial limiting stability of the differential bearing 2 and the output oil seal 3 .

As shown in FIGS. 2 and 4 , as an embodiment, an oil drain chamber 15 is provided on the side of the first oil baffle 12 away from the differential bearing 2. The oil drain chamber 15 is in the shape of an elongated strip, wherein the first end is connected to the exhaust passage 13, and the second end is lower in the vertical direction than the first end. Since the second end is lower than the first end, the oil mist needs to rise to a height of one end in order to enter the exhaust passage 13 through the first end of the oil drain chamber 15, thereby reducing the oil mist from entering the exhaust passage 13. At the same time, since it is more difficult for the oil mist to enter the exhaust passage 13, the oil mist will gather in the oil drain chamber 15. The second end of the exhaust passage 13 is lower, and the oil mist gathers at the second end by its own gravity, thereby falling into the oil pool of the drive axle from the second end, thereby reducing the problem of the oil mist entering the exhaust passage 13. In addition, when the vehicle is tilted to the right, the amount of oil mist is large, and the second end is lower than the first end, so that the oil mist can be gathered into small oil droplets and flow out from the second end, thereby avoiding the oil mist from entering the exhaust passage 13 through the first end, thereby reducing the problem of lubricating oil leakage during the pressure relief process.

Optionally, the oil discharge chamber 15 may be an arc-shaped structure or a longitudinally elongated structure.

As an embodiment, the peripheral wall of the oil drain chamber 15 which is closest to the center of the side cover 1 is inclined downward. When the vehicle tilts to the right, the amount of oil mist is large, and the peripheral wall of the oil drain chamber 15 which is closest to the center of the side cover 1 is inclined downward, so that the oil mist on the peripheral wall of the oil drain chamber 15 can flow directly into the oil pool of the drive axle through the inclined peripheral wall, thereby preventing the oil mist from entering the exhaust channel 13 through the first end of the oil drain chamber 15, reducing the problem of lubricating oil leakage during the pressure relief process.

As an implementation mode, the axis of the exhaust passage 13 is set at an angle to the vertical line perpendicular to the bottom wall of the oil drain chamber 15, which is equivalent to the exhaust passage 13 extending along the radial direction of the side cover 1, and the oil drain chamber 15 is recessed along the axial direction of the side cover 1. The oil mist itself has weight. During the pressure relief process, the oil mist will be directly gathered in the oil drain chamber 15 along the direction of the recess of the oil drain chamber 15 due to its own inertia and the pressure difference, and it is difficult for the oil mist to enter the exhaust passage 13 in the form of a turn, thereby reducing the oil mist entering the exhaust passage 13.

As shown in FIG. 4 , as an embodiment, the exhaust passage 13 includes a plurality of connecting sections 131 , and the diameters of the plurality of connecting sections 131 are different, so as to reduce the oil mist from being discharged by the vent plug.

Optionally, two connecting sections 131 may be provided. When the diameter of the connecting section 131 communicating with the oil discharge chamber 15 is smaller than the connecting section 131 at the upper end, it is equivalent to that the inlet of the exhaust passage 13 is smaller, and a large amount of oil mist can be stopped around the inlet of the exhaust passage 13, thereby reducing the oil mist from entering the exhaust passage 13.

When the diameter of the connecting section 131 connected to the oil drain chamber 15 is larger than the connecting section 131 at the upper end, the connecting position of the two connecting sections 131 will stop the oil mist from entering the connecting section 131 at the upper end, and the oil mist gathers at the connecting section 131 at the lower end and flows into the oil drain chamber 15 by gravity, thereby reducing the oil mist from entering the vent plug.

As shown in FIGS. 4 and 6 , as an implementation mode, two adjacent connecting sections 131 are connected by a transition curved surface 132 . The transition curved surface 132 is provided to facilitate the flow of oil; in addition, it also serves to prevent oil mist from flowing into the upper connecting section 131 .

Optionally, when the diameter of the connecting section 131 communicating with the oil discharge chamber 15 is smaller than the connecting section 131 at the upper end, the two adjacent connecting sections 131 are connected by the transition curved surface 132, which is equivalent to the entrance of the exhaust passage 13 being smaller, and the oil mist of the connecting section 131 at the upper end is gathered into oil droplets, which flow into the connecting section 131 at the lower end through the transition curved surface 132. The transition curved surface 132 guides the oil, facilitates the flow of the oil, reduces the accumulation of the oil in the connecting section 131 at the upper end, and reduces the problem of oil leakage when the vent plug is depressurized;

When the diameter of the connecting section 131 connected to the oil drain chamber 15 is larger than the connecting section 131 at the upper end, the two adjacent connecting sections 131 are connected by a transition surface 132, and the oil mist is stopped on the transition surface 132. The transition surface 132 can stop the oil mist from entering the connecting section 131 at the upper end.

As shown in Figures 5 and 7, as an implementation mode, the side cover 1 is connected to the drive axle housing 6, and a recessed area 16 is provided on the side of the side cover 1 facing the differential bearing 2. A protruding second oil baffle plate 17 is provided in the recessed area 16. The extended edge of the second oil baffle plate 17 is adapted to the driven bevel gear 4 and the differential housing 5. The second oil baffle plate 17 is clearance-matched with the driven bevel gear 4 and the differential housing 5. When the differential is rotating, the second oil baffle plate 17 can intercept more lubricating oil, so that the lubricating oil flows into the outside of the differential bearing 2 through the second oil baffle plate 17, thereby increasing the lubrication amount of the differential bearing 2.

The lubrication structure of the drive axle further includes a driven bevel gear 4 , which is fixedly connected to the differential housing 5 .

Optionally, the driven bevel gear 4 and the differential housing 5 are welded by laser.

Optionally, the drive axle includes a driving shaft, a driving bevel gear is installed at the end of the driving shaft, the driving bevel gear is welded to the driving shaft, a part of the driving bevel gear is immersed in the oil pool of the drive axle housing 6, and the driving bevel gear is meshed with the driven bevel gear 4, thereby driving the driven bevel gear 4 and the differential housing 5 to rotate.

The side cover 1 has a certain thickness. By setting the recessed area 16, the side cover 1 in the area where the recessed area 16 is located becomes thinner. The second oil baffle plate 17 can form a retention space with the bottom and side of the recessed area 16 for the lubricating oil intercepted by the second oil baffle plate 17, thereby increasing the lubrication amount of the differential bearing 2.

Optionally, the drive axle also includes a differential, which is installed in the drive axle housing 6. The differential includes a left differential bearing and a right differential bearing. The differential also includes a differential housing 5. The right differential bearing is installed on the right side of the differential housing 5, and the left differential bearing is installed on the left side of the differential, wherein the right differential bearing is the differential bearing 2 close to the side cover 1.

Optionally, when the differential housing 5 rotates, the second oil baffle plate 17 can intercept most of the lubricating oil, and the intercepted lubricating oil flows into the differential bearing 2 through one side of the second oil baffle plate 17, while a small amount of lubricating oil that is not blocked falls into the recessed area 16 on the other side of the second oil baffle plate 17 and is guided to the outside of the differential bearing 2 through the recessed area 16.

Optionally, the second oil baffle 17 divides the recessed area 16 into two parts, wherein the space in one part is larger than the space in the other part, and the larger space can allow the vehicle to retain more lubricating oil when moving forward.

Optionally, the side cover 1 is connected to the drive axle housing 6 via a plurality of bolts.

As shown in FIG. 7 , as an implementation mode, the opening of the recessed area 16 faces the differential bearing 2, and the second oil baffle plate 17 is located above the differential bearing 2, so that the lubricating oil in the recessed area 16 and the lubricating oil on the second oil baffle plate 17 can flow to the outside of the differential bearing 2 by their own gravity, thereby lubricating the right differential bearing, and when lubricating the differential bearing 2, lubrication can be achieved without the need for an additional mechanical oil pump.

Optionally, the differential bearing 2 is a tapered bearing with a pumping effect. The differential bearing 2 can pump the lubricating oil from the outside of the differential bearing 2 to the position of the differential housing 5, and then the lubricating oil enters the oil pool in the drive axle housing 6, reducing the waste of lubricating oil.

As shown in FIG. 8 , optionally, a plurality of oil stirring parts 51 are provided on the side of the differential housing 5 facing the differential bearing 2. By providing the plurality of oil stirring parts 51, when the differential housing 5 rotates, the oil stirring parts 51 can splash the oil in the oil pool onto the differential bearing 2, thereby lubricating the differential bearing 2 and improving the lubrication effect.

Optionally, a plurality of oil stirring portions 51 are evenly arranged along the circumference of the differential housing 5 .

Optionally, the oil stirring portion 51 may be a groove structure, and the groove is cast, which can reduce the weight of the differential housing 5, further reduce the weight of the entire vehicle, and improve the cruising range.

In addition, the oil stirring portion 51 may also be a convex rib, thereby improving the oil stirring effect.

As shown in FIG8 , optionally, the oil stirring portion 51 includes a recessed portion, one side of the recessed portion is an opening, and the recessed portion also includes at least two side walls extending to the opening, wherein the length of one side wall is greater than the length of the other side wall, and the side wall with the shortest length is configured as the first side wall 511, and the tangent direction of the first side wall 511 extending to the opening position is in the same direction as the rotation direction of the differential case 5 when the vehicle is moving forward, so that when the vehicle moves forward, the differential case 5 also rotates synchronously, and since the length of the first side wall 511 is the shortest, the time required for the lubricating oil to pass through the connection position of the first side wall 511 and the second side wall 512 will be shortened, and the connection position of the first side wall 511 and the second side wall 512 is prone to generate turbulence during the oil stirring process, thereby increasing the amount of oil stirring, and the first side wall 511 is connected to the second side wall 512. The tangent line extending from the wall 511 to the opening position is in the same direction as the rotation direction of the differential housing 5 when the vehicle is moving forward. In this way, when the vehicle is moving forward, due to the rotation of the differential housing 5, the connection position of the first side wall 511 and the second side wall 512 can stir more oil to improve the lubrication effect of the differential bearing 2; and the side wall with the longest length is configured as the second side wall 512. The second side wall 512 is the longest. When reversing, the time required for the lubricating oil to pass through the connection position of the first side wall 511 and the second side wall 512 will be longer, and when reversing, the rotation speed of the differential housing 5 will also slow down. Therefore, the turbulence generated at the connection position of the first side wall 511 and the second side wall 512 during the oil stirring process will not be very rapid, and a small amount of oil can be stirred up to reduce oil loss.

As shown in FIG8 , the first side wall 511 and the second side wall 512 are both arc-shaped walls, and the first side wall 511 has the largest curvature. When the vehicle moves forward, the differential housing 5 also rotates synchronously. The first side wall 511 is prone to generate turbulence during the oil stirring process. Therefore, the first side wall 511 can enable the oil stirring portion 51 to stir more lubricating oil, and the side wall with the longest length is configured as the second side wall 512. The second side wall 512 is the longest. When reversing, the second side wall 512 has a smaller curvature, and the differential housing 5 rotates slowly. The second side wall 512 is not prone to generate turbulence, and can stir up a small amount of oil to reduce oil loss.

In a second aspect, an embodiment of the present application provides a vehicle, which is equipped with the lubrication structure of the drive axle provided in the first aspect.

The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of protection of the present application.

The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

It should be noted that, in this article, relational terms such as first and second, etc. are only used 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. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

Claims (12)

1. A side cover of a drive axle is characterized in that,

The side cap is equipped with the through-hole, the side cap still is equipped with first oil baffle, first oil baffle is followed radially inwards extend of the pore wall of through-hole, be equipped with the exhaust passage that is used for installing the breather plug on the side cap, the entry setting of exhaust passage is in on the first oil baffle and opposite to differential mechanism bearing.

2. The side cover according to claim 1, wherein the projection of the first oil baffle plate toward the differential bearing covers the projection of the retainer of the differential bearing in the same horizontal direction.

3. The side cover according to claim 1 or 2, wherein the first oil baffle is located in an upper half area of the through hole.

4. The side cover according to claim 1 or 2, wherein both sides of the first oil baffle are respectively for abutting with a differential bearing and an output oil seal.

5. The side cover according to claim 1 or 2, wherein an oil drain chamber is provided on a side of the first oil baffle facing away from the differential bearing, the oil drain chamber being elongated, wherein a first end communicates with the air discharge passage, and a second end is lower in height in a vertical direction than the first end.

6. The side cover according to claim 5, wherein the oil drain chamber extends obliquely downward from a nearest peripheral wall of the side cover from a center of the side cover.

7. The side cover according to claim 5, wherein the axis of the exhaust passage is disposed at an angle to a perpendicular to a bottom wall of the oil drain chamber.

8. The side cover according to claim 1 or 2, wherein the exhaust passage includes a plurality of connection sections, and the diameters of the plurality of connection sections are different.

9. The side cover according to claim 8, wherein two adjacent connecting sections are connected by a transition curved surface.

10. The side cover according to claim 8, wherein a recessed area is arranged on one side of the side cover facing the differential bearing, a second oil baffle plate is arranged in the recessed area, the extending edge of the second oil baffle plate is matched with the driven bevel gear and the differential housing, and the second oil baffle plate is in clearance fit with the driven bevel gear and the differential housing.

11. The side cover of claim 10, wherein the recessed area opens toward the differential bearing and the second oil baffle is located above the differential bearing.

12. A vehicle, characterized in that the vehicle is mounted with a side cover of the transaxle of claim 1.