JPH08210472A - Lubricating mechanism for final reduction gear - Google Patents

Abstract

PURPOSE: To provide a lubricating mechanism wherein seizure can be prevented even when decreased a lubricating oil amount supplied to a small diametric side of a tapered roller relating to a tapered roller bearing of supporting a drive pinion of an end reduction gear. CONSTITUTION: Relating to a pair of tapered roller bearings 14, 16 of supporting a shaft part 12 of a drive pinion 10 against a differential carrier 18, lubricating oil scraped up by a ring gear 22 is supplied to between the bearings through an introducing path 40 and an opening 44. On the other hand, in the vicinity of a small diametric side of a tapered roller 34 of the tapered roller bearing 14 in a front side, a circular annular partition 46 is arranged between itself and a collapsible spacer 38 with a prescribed clearance left so as to impede an inflow of air due to pump action of the tapered roller bearing 14 in the case of decreasing a supply amount of lubricating oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating mechanism for a final reduction gear, and more particularly to a technique for preventing seizure of a bearing when the amount of lubricating oil supplied is reduced.

[0002]

2. Description of the Related Art Generally, a final reduction gear for an automobile is provided on (a) a differential carrier and (b) rotatably around the shaft center of the differential carrier, and the tip of a shaft portion is connected to a propeller shaft. A drive pinion that is driven to rotate, and (c) a ring gear that is disposed within the differential carrier so as to be rotatable about a substantially horizontal axis and that is engaged with the drive pinion and is rotated at a reduced speed. The drive pinion is rotatably supported by a pair of bearings at its shaft portion. In order to lubricate the final deceleration device, the differential carrier is filled with a predetermined amount of lubricating oil and is scraped up as the ring gear rotates to lubricate each part. Further, in order to lubricate a pair of bearings supporting the shaft portion of the drive pinion, for example, an actual open flat plate 3-2975 is used.
As described in Japanese Patent Publication No. 5, the differential carrier is provided with an oil supply passage for supplying lubricating oil to the tip end side portion of the front bearings located on the tip end sides of the intermediate portion and the shaft portion of both bearings. An oil seal is provided on the tip side of the front bearing to prevent the lubricating oil from leaking to the outside. Further, the front side bearing is usually constituted by a tapered roller bearing arranged between the shaft portion and the differential carrier in a posture in which the large diameter side of the tapered roller is the tip end side of the shaft portion, and A part of the lubricating oil supplied to the portion between the side bearing and the side bearing is sent to the tip side of the shaft portion by the pumping action of the front side bearing.

[0003]

However, in the lubricating mechanism of such a final reduction gear, the lubricating oil is directed to the side surface of the differential carrier, that is, the side wall parallel to the rotation plane of the ring gear, when lateral acceleration is applied. When the amount of flow and the amount of lubricating oil picked up by the ring gear decreases and the supply amount to the bearing side decreases, the front bearing may suck in air and blow off the lubricating oil adhering to the bearing, impairing seizure resistance. there were.

The present invention has been made in view of the above circumstances, and an object of the present invention is to prevent the bearing from seizing even when the supply amount of lubricating oil is reduced.

[0005]

In order to achieve the above object, the present invention provides (a) a differential carrier, and (b) a differential carrier rotatably around an axis and a shaft portion. A drive pinion whose tip is connected to a propeller shaft to be driven to rotate, and (c) is disposed in the differential carrier so as to be rotatable about a substantially horizontal axis, and is engaged with the drive pinion to be decelerated and rotated. The ring gear and (d) a tapered roller which is arranged between the shaft portion and the differential carrier in a posture in which the large diameter side of the tapered roller is the tip side of the shaft portion of the drive pinion, and rotatably supports the shaft portion. (E) The tapered roller of the tapered roller bearing, in which the lubricating oil scraped by the rotation of the ring gear is rotated. A lubrication mechanism of a final reduction gear that includes an oil supply path provided in the differential carrier so as to be guided to the vicinity of the small diameter side, and lubricates the tapered roller bearing with the lubricating oil supplied through the oil supply path, (F) A partition wall for obstructing air flow is provided on at least one of the shaft portion side and the differential carrier side in the vicinity of the small diameter side of the tapered roller of the tapered roller bearing.

[0006]

In the lubrication mechanism of such a final reduction gear, since the partition wall for obstructing the air flow is provided in the vicinity of the tapered roller small diameter side of the tapered roller bearing,
Even if lateral acceleration acts, the amount of lubricating oil picked up by the ring gear decreases and the supply amount decreases, and even if air is sucked in from the small diameter side of the tapered roller due to the pumping action of the tapered roller bearing, the presence of the partition wall The amount of suction is reduced by blocking the flow of air. Since the tapered roller bearing has a not so large pumping action, the suction amount decreases when the air flow area becomes small to some extent. As a result, deterioration of seizure resistance due to blowing off the lubricating oil adhering to the tapered roller bearing is suppressed, and the life of the bearing is improved.

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view seen from a side of a vehicle showing an example of a final reduction gear for a vehicle equipped with a lubricating mechanism of the present invention.
The right side is the front side of the vehicle and the upper side is the upper side of the vehicle. In this final reduction gear transmission, a drive pinion 10 is disposed in a differential carrier 18 via a pair of front side tapered roller bearings 14 and rear side tapered roller bearings 16 so as to be rotatable about an axis in the vehicle longitudinal direction. There is. The drive pinion 10 is supported by the pair of bearings 14 and 16 in the shaft portion 12 in a posture in which the rear side having the pinion portion 11 is slightly inclined downward, and the tip of the shaft portion 12 opposite to the pinion portion 11 is provided. A propeller shaft (not shown) is connected to the shaft via a companion flange 20 so that torque from a drive source such as an engine is transmitted and the propeller shaft is rotationally driven.

The pinion portion 11 of the drive pinion 10 is meshed with a ring gear 22, and the differential case 24 is rotated integrally with the ring gear 22 so that the differential gear 24 in the differential case 24 can move the left and right sides. Rotational force is transmitted to the drive wheels (not shown), and differential rotation between the drive wheels is allowed during cornering. The ring gear 22 is integrally attached to the differential case 24 in the differential carrier 18, and is substantially horizontal to the drive pinion 10 at a substantially right angle via a bearing (not shown).
That is, it is arranged rotatably around the axis of the vehicle in the width direction, and when it is engaged with the drive pinion 10, it is decelerated and rotated according to the tooth ratio thereof.
It should be noted that the teeth of the ring gear 22 are not shown.

The companion flange 20 is arranged so as not to be rotatable relative to the shaft portion 12 of the drive pinion 10 by spline fitting, etc., and is not disengaged by a tightening nut 28, and the front side tapered roller is also provided. The tapered roller bearings 14 and 16 are positioned by being brought into contact with the inner ring 32 of the bearing 14. An oil seal 30 is provided between the companion flange 20 and the differential carrier 18, and while allowing the rotation of the companion flange 20, an oil-tight seal is provided between the two to prevent the lubricating oil from leaking to the outside. are doing.

In the pair of tapered roller bearings 14 and 16, the large diameter side of each tapered roller faces outward, that is, in the front side tapered roller bearing 14, the large diameter side of the tapered roller 34 is the tip side of the shaft portion 12 of the drive pinion 10. (The front side of the vehicle), and in the rear side tapered roller bearing 16, the large diameter side of the tapered roller 36 becomes the pinion portion 11 side (the rear side of the vehicle) and the shaft portion 12 and the cylindrical portion 42 of the differential carrier 18 are arranged. Are arranged between the two. Since the tapered roller bearings 14 and 16 are given a preload corresponding to the tightening torque of the tightening nut 28, the tightening nut 28 has a predetermined length, such as the longest life of the tapered roller bearings 14 and 16. It is tightened with a predetermined tightening torque. In addition, in order to facilitate adjustment of this preload,
A substantially cylindrical collapsible spacer 38 is interposed between the inner rings of the tapered roller bearings 14 and 16 around the shaft portion 12. In this embodiment, a pair of tapered roller bearings 1
The front tapered roller bearing 14 of the rollers 4 and 16 corresponds to the tapered roller bearing according to claim 1.

A first space 39a in which the ring gear 22 is disposed is located above the cylindrical portion 42 in which the drive pinion 10 is disposed in the differential carrier 18.
Is provided to the upper wall surface of the cylindrical portion 42 that constitutes the introduction path 40.
Second space 39 between the pair of tapered roller bearings 14 and 16
An opening 44 communicating with b and an opening 45 communicating with the third space 39c between the front tapered roller bearing 14 and the oil seal 30 are formed. Then, the lubricating oil filled in the differential carrier 18 is accumulated in the lower portion of the lowest first space 39a, and is stirred and scraped up as the ring gear 22 and the differential case 24 rotate, While lubricating those meshing parts and bearings, part of the scraped lubricant oil is introduced from the introduction passage 40 into the openings 44, 45.
Is supplied to the second space 39b and the third space 39c through the above to lubricate the tapered roller bearings 14 and 16 and the oil seal 30. The introduction passage 40 and the opening 44 correspond to an oil supply passage that guides the lubricating oil to the vicinity of the tapered roller 34 of the tapered roller bearing 14 on the smaller diameter side.

On the other hand, the tapered roller 3 of the tapered roller bearing 14
4, a ring-shaped partition wall 46 is provided near the small diameter side, that is, on the left side of the tapered roller bearing 14 in FIG. FIG. 2 is an enlarged view of an essential part showing a part of FIG. 1 in detail. The dimension c of the predetermined gap is set to a dimension as small as possible within a range in which the required minimum supply amount of lubricating oil is allowed to flow. It is set to, for example, about 2 mm (constant around the entire circumference), although it depends on the viscosity of the lubricating oil. This partition 4
6 is composed of a pressed sheet metal member or the like, and is fixed to the inner peripheral side of the cylindrical portion 42 of the differential carrier 18 by press fitting or the like via a cylindrical fitting portion 48 provided on the outer peripheral portion. It has become. Generally, in a tapered roller bearing, since there is a pumping action from the small diameter side to the large diameter side due to the peripheral speed difference between the large diameter side and the small diameter side of the tapered roller, it is supplied into the second space 39b through the opening 44. A part of the lubricating oil is sucked from the gap between the collapsible spacer 38 and the partition wall 46 by the pumping action of the tapered roller bearing 14 as shown by the broken arrow in FIG. Sent to.

Here, when lateral acceleration is applied during cornering of the automobile, the lubricating oil flows to the side surface inside the differential carrier 18, and the amount of the lubricating oil scraped up by the ring gear 22 decreases and the supply amount decreases. Air may be sucked in place of the lubricating oil due to the pumping action of the tapered roller bearing 14. However, in the present embodiment, the presence of the partition wall 46 hinders the inflow of air, and therefore compared with the case where the partition wall 46 is not provided. The air intake amount is reduced. Since the tapered roller bearing 14 does not have such a large pumping action, the suction amount decreases when the air flow area decreases to some extent. As a result, a decrease in seizure resistance due to the sucked air blowing off the lubricating oil adhering to the tapered roller bearing 14 is suppressed, and the bearing life is improved. In the tapered roller bearing 14, the sliding contact between the front flange portion 32a (see FIG. 2) of the inner ring 32 and the large-diameter side end surface of the tapered roller 34 is apt to cause seizure, while the sucked air When the air is blown out to the front side, the lubricating oil adhering to the collar portion 32a and its vicinity is blown off, so that the seizure resistance is deteriorated due to the intake of air. Since the rear side tapered roller bearing 16 is located below the front side tapered roller bearing 14, the lubricating oil easily flows in, and since the amount of the lubricating oil adhered near the ring gear 22 is large, seizure due to oil shortage occurs. There is almost no fear of.

Further, the partition wall 46 of this embodiment also functions as a lubricating oil reservoir, and the lubricating oil supplied into the tapered roller bearing 14 and the third space 39c is the partition wall 46 as shown by the chain double-dashed line in the figure. It is stored up to the height of the lower edge of the inner diameter. Therefore, the tapered roller bearing 14 and the oil seal 30 are sufficiently lubricated even during normal traveling, and
The lubricating oil temperature is low, the fluidity is poor, and sufficient lubricating oil cannot be supplied, so that a good lubricating action can be obtained even at the beginning of running, and in this respect, the seizure resistance is improved. Further, as described above, the lubricating oil is stored up to the level shown by the chain double-dashed line in the drawing on the front side of the partition wall 46, while on the rear side of the partition wall 46, the tapered roller bearing 16, the ring gear 22, and the differential gear are used. Since it is sufficient that the case 24 is filled with the lubricating oil up to the lubricating oil level indicated by the one-dot chain line, the differential carrier 18
The amount of lubricating oil to be filled inside is approximately the same as the one indicated by the one-dot chain line, and the seizure resistance is reduced compared to when the lubricating oil is filled up to the one indicated by the two-dot chain line. It is possible to reduce the amount of filling and reduce power loss due to stirring resistance without inviting.

As described above, in the lubrication mechanism of the final reduction gear transmission of this embodiment, the tapered rollers 34 of the tapered roller bearing 14 are used.
Of the partition wall 46 near the small diameter side of the pump, that is, the suction side of the pump action.
Is provided, the inflow of air is obstructed when the amount of lubricating oil is reduced to prevent the residual lubricating oil from being blown off by the air, and the tapered roller bearing 14
Seizure is prevented. Further, in this embodiment, since the annular partition wall 46 is fixedly mounted on the differential carrier 18, the partition wall 46 also functions as a lubricating oil reservoir, and a good lubricating action can be obtained with a small amount of lubricating oil. Power loss is reduced.

Next, different modes of the partition wall in the above-mentioned embodiment will be described. The parts substantially common to those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof will be omitted.

The partition wall 50 shown in FIG. 3 has an annular shape having an outer diameter that forms a predetermined gap with the inner peripheral surface of the cylindrical portion 42 of the differential carrier 18, and has an inner peripheral portion. The collapsible sleeve 38 is fixed to the collapsible sleeve 38 by press fitting, welding or the like through an integrally provided cylindrical fitting portion 52. Also in this embodiment, when the lubricating oil is reduced, the inflow of air is obstructed to prevent the residual lubricating oil from being blown off by the air, seizure of the tapered roller bearing 14 is prevented, and the necessary and sufficient lubricating oil is supplied. Good lubrication can be obtained.

The partition wall 60 shown in FIG. 4 is a tapered roller bearing 1
The outer ring 62 of FIG. 4 is integrally provided in an inward flange shape from the suction side end of the outer ring 62 so as to form a predetermined gap with the collapsible sleeve 38.
In this embodiment as well, like the partition wall 48, the intake amount of air is reduced and it functions as a lubricating oil sump, and the same effect as the embodiment of FIG. 1 is obtained.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the present invention can be implemented in other modes.

For example, the dimension c of the predetermined gap may be appropriately changed according to the size and form of the front side tapered roller bearing 14 or the positional relationship of the partition wall 46 and the like with respect to the tapered roller bearing 14, and may not necessarily be around the axis. Does not have to be constant over the entire circumference. The shape of the fitting portion 48 can also be changed as appropriate.

Further, in place of the partition walls 46, 50, 60 forming the predetermined gap, a partition wall having a gap of substantially zero is provided and a large number of fine pores are formed in the partition wall, so that air It may be configured to block the inflow and allow the inflow of lubricating oil.

Further, the partition wall 46 constitutes a single wall in which the axial length of the portion having the predetermined gap c is about the thickness of the sheet metal, but the section of the gap c is continuous. The differential carrier 18 is configured to have a cylindrical portion having a predetermined axial length or, for example, two or more partition walls 46 and 50 are combined to be disposed.
Multiple rows of walls protruding alternately from both the side and the shaft portion 12 side may be configured.

Further, the partition wall 60 is a tapered roller bearing 14
Although it is provided integrally with the outer ring 62, it may be provided integrally with the collapsible spacer 38 and the inner ring 32. It is also possible to provide partition walls so as to obstruct the flow of air between the inner ring 32 and the outer ring 62.

Further, in the above-described embodiment, the partition is not provided for the tapered roller bearing 16 on the rear side, but depending on the kind of the final reduction gear, the tapered roller bearing 16 may be provided if necessary.
Similarly, it does not matter that a partition wall is provided.

In the above embodiment, the drive pinion 1
Although the tip end side of the shaft portion 12 of No. 0 is arranged so as to be inclined slightly upward, the present invention can be applied even if it is substantially horizontal.

In the above embodiment, the lubricating oil is supplied from the opening 45 into the third space 39c.
The opening 45 is not always necessary, and the tapered roller bearing 14 may only supply the lubricating oil into the third space 39c.

In the above embodiment, the partition wall 46 also functions as a lubricating oil sump, but the third space 39
It is also possible to form a return oil passage for returning the lubricating oil in c to the first space 39a side in the drive pinion 10, the differential carrier 18, or the like so that the lubricating oil can be circulated.

Although not illustrated one by one, the present invention can be carried out in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a final reduction gear device including a lubrication mechanism that is an embodiment of the present invention.

FIG. 2 is an enlarged view of an essential part showing a part of FIG. 1 in detail.

FIG. 3 is a sectional view of an essential part showing another example of the mode of the partition wall in the embodiment of FIG.

FIG. 4 is a sectional view of a main part showing still another mode example of the partition wall in the embodiment of FIG.

[Explanation of symbols]

 10: Drive pinion 12: Shaft part 14: Tapered roller bearing 18: Differential carrier 22: Ring gear 34: Tapered roller 40: Introduction path (oil supply path) 44: Opening (oil supply path) 46, 50, 60: Partition wall

Claims (1)

[Claims] 1. A differential carrier, a drive pinion which is rotatably mounted on the differential carrier and whose shaft end is connected to a propeller shaft to be driven to rotate, and a substantially horizontal shaft center. A ring gear that is rotatably disposed in the differential carrier, is engaged with the drive pinion and is rotated at a reduced speed, and the shaft portion in a posture in which the large diameter side of the tapered roller is the tip side of the shaft portion of the drive pinion. And a tapered roller bearing which is disposed between the differential carrier and rotatably supports the shaft portion, and the lubricating oil scraped up by the rotation of the ring gear has a smaller diameter side of the tapered roller of the tapered roller bearing. An oil supply path provided in the differential carrier so as to be guided to the vicinity, A lubrication mechanism of a final reduction gear device that lubricates the tapered roller bearing with the lubricating oil supplied through a supply path, in the vicinity of the small diameter side of the tapered roller of the tapered roller bearing, on the shaft side and the differential carrier side. A lubricating mechanism for a final speed reducer, characterized in that a partition wall that obstructs the flow of air is provided on at least one side.