JPH055316Y2 - - Google Patents

Description

[Detailed description of the invention] (Technical field of the invention) The invention relates to a lubrication structure of a final reduction gear device.
In particular, the present invention relates to a lubrication structure for a sliding portion between a case that accommodates a differential pinion and a side gear, and a side gear shaft that protrudes from the case.

(Prior art) The case of the final reduction gear, the so-called differential case, is rotatably supported by two rolling bearings arranged at a distance in the differential carrier, and a ring gear is mounted on the case. Installed. On the other hand, there are 2 or 4 in the case.
A number of pinions and two side gears are arranged, and a side gear shaft coupled to each side gear passes through the inside of the rolling bearing and projects outward from the case and the differential carrier.

(Problem to be solved by the invention) The two rolling bearings are configured to be lubricated by the lubricating oil splashed up by the rotation of the ring gear, but the rolling bearing located far from the ring gear is lubricated by the lubricating oil. is originally difficult to reach. Moreover,
The lubricating oil that reaches the rolling bearing is blown to the outer periphery by the centrifugal force acting on the rolling bearing, so the lubricating oil reaches the part of the case that engages the rolling bearing located far from the ring gear, and the side gear shaft inside this part. The lubrication of the sliding parts seems to be insufficient. If a differential occurs when there is a lack of lubricating oil, relative movement will occur between the case and the side gear in the sliding part, which may cause seizure or abnormal wear in this part. This causes problems such as oil leaks and vibrations.

In the final reduction gear device described in Japanese Utility Model Application Publication No. 60-61558, a deflector is attached to the case to restrict the flow of lubricating oil toward the differential carrier through the rolling bearing, so that the lubricating oil does not pass directly through the rolling bearing. It is used as a stopper for lubricating oil that may get wet. However, it does not actively guide lubricating oil to the sliding part between the case and the side gear.

An object of the present invention is to provide a final reduction gear device that can actively guide lubricating oil to the sliding part between the case and the side gear and eliminate the lack of lubricating oil in this sliding part.

(Means for Solving the Problems) The present invention is a lubrication structure for a final reduction gear device in which a side gear shaft extends through a bearing part of a carrier, and includes an inner race provided with an oil hole penetrating in the radial direction. a rolling bearing mounted on the bearing portion of the carrier and a boss portion through which the side gear shaft is provided with an oil hole penetrating in the radial direction, and the boss portion is fitted to the inner race. The present invention includes a case in which an oil hole in a boss portion communicates with an oil hole in the inner race, and a wear-resistant layer interposed between an outer circumferential surface of the side gear shaft and an inner circumferential surface of the boss portion of the case.

In a preferred embodiment, the rolling bearing is a tapered roller bearing, and the oil hole in the inner race is located near the shoulder that locks the end face of the roller. The wear-resistant layer is a metal or resin with a low coefficient of friction. This is formed as a pushbutton, and in addition to being fitted into the boss portion of the case, it is also coated on the inner circumferential surface of the boss portion of the case or the outer circumferential surface of the side gear shaft.

(Functions and Effects) The lubricating oil that reaches the rolling bearing is blown to the outer circumference by the action of centrifugal force acting on the rolling bearing and collects on the inner peripheral surface of the outer race. Attach to moving objects,
Guided by the inner race. The inner race has an oil hole, so lubricating oil enters the oil hole.
Furthermore, the oil reaches the wear-resistant layer through the oil hole in the boss part of the case, and lubricates the sliding part between the case and the side gear shaft.

Oil holes are provided in the inner race that directly contacts the rolling elements.
Since an oil hole communicating with the oil hole is provided in the boss part of the case located inside the inner race,
Even if centrifugal force acts on the rolling bearing, lubricating oil is easily guided to the oil holes in the inner race by the rolling elements. Since lubricating oil is continuously supplied to these oil holes, even if centrifugal force acts on the rolling bearing,
The lubricating oil can reach the wear-resistant layer, and the sliding parts between the case and the side gear shaft are well lubricated.

Because the lubricating oil is sufficiently guided to the sliding part and there is a wear-resistant layer, the seizure resistance and wear resistance of the sliding part are improved, compared to conventional final reduction gearing. , it is possible to increase the joint angle of the drive shaft, and the vehicle height can be increased. This is because even if the joint angle of the drive shaft becomes larger and the load in the direction perpendicular to the axis of the side gear shaft increases, the possibility of seizure or wear caused by metal contact between the case and the side gear shaft is greatly reduced. It is from.

(Example) As shown in FIGS. 1 and 2, the lubrication structure 1
0 lubricates a portion of the final reduction gear device 12 where the side gear shaft 14 extends through the bearing portion 17a of the carrier 16, and includes a rolling bearing 18.

The final reduction gearing 12 includes a carrier 16 and a case 20 disposed within the carrier 16.
The carrier 16 also serves as a transmission case that houses a vehicle transmission, and has two bearings 17a and 17b spaced apart.
has. Rolling bearing 18 is one bearing part 17
In a, the rolling bearing 22 is attached to the other bearing portion 17b. Both rolling bearings are tapered roller bearings.

The case 20 has two boss parts 21a and 21b spaced apart from each other, the boss part 21a is connected to the rolling bearing 18, and the boss part 21b is connected to the rolling bearing 2.
2, and the case 20 is rotatably supported.

A ring gear 24 is attached to the case 20. The lubricating oil is splashed up by this ring gear 24, and on the other hand, the lubricating oil is pumped up by the oil supply hole 2 formed in the carrier 16.
6 to the rolling bearing 18 and, on the other hand, to the rolling bearing 22 through the oil supply hole 28 formed in the carrier 16, in this case reaching the vicinity of the rolling bearing 18 located far from the ring gear 24. Lubricant is low. Therefore, the present invention is
It is intended that the rolling bearing 18 located far from the link gear 24 be well lubricated. However, it is more preferable to apply the same configuration to the rolling bearing 22 located near the ring gear 24.

The rolling bearing 18 includes an inner race 30, an outer race 32, and a plurality of rollers 34. The inner race 30 has an outer peripheral surface formed as a tapered surface, and has shoulders 31a and 31b at both ends. The outer diameter of the tapered surface of the shoulder 31b is the same as the shoulder 31a.
An oil hole 36 is provided near the shoulder 31b and penetrates in the radial direction. Oil hole 3
It is preferable that the number 6 is plural and arranged at intervals in the circumferential direction. The inner race 30 is fitted onto the boss portion 21 of the case 20 so that the shoulder 31b is located inside the case 20.

The outer race 32 of the rolling bearing 18 has an inner circumferential surface formed as a tapered surface, and is fitted into the bearing portion 17a of the carrier 16 such that the portion of the tapered surface with the smaller inner diameter is located outside the carrier 16. In the illustrated embodiment, an annular washer 3 is provided between the outer race 32 and the bearing portion 17a of the carrier 16 for applying a preload to the rolling bearing.
3 is placed. A plurality of rollers 34 are arranged in the space between the inner race 30 and the outer race 32, and are arranged on the shoulders 31a, 31b of the inner race 30.
is positioned.

The boss portion 21a of the case 20 has an annular groove 38 on its outer peripheral surface and an oil hole 40 that penetrates from the annular groove 38 in the radial direction. The boss portion 21a is fitted into the inner race 30 of the rolling bearing 18, and the oil hole 4 is fitted into the inner race 30 of the rolling bearing 18.
0 is communicated with the oil hole 36 of the inner race 30.
As shown in the figure, if there is an annular groove 38, the oil hole 40
The oil holes 36 and 40 communicate with each other through the annular groove 38, and communication between the two oil holes 36 and 40 becomes easy and reliable.

The pinion shaft 44 is attached to the case 20 along the rotational axis of the case 20, that is, the two rolling bearings 1
8 and 22, and two pinions 46 are rotatably supported by the pinion shaft 44. On the other hand, two side gears 48 are disposed coaxially with the rotational axis of the case 20 and mesh with the pinion 46, respectively.

One side gear shaft 14 is a carrier 1
Oil seal 50 disposed on bearing portion 17a of No. 6
It is inserted into the case 20 through the case 20 and is spline-fitted to one side gear 48 inside the case 20. The other side gear shaft 14 has the same configuration and is inserted into the case 20 through an oil seal 50 disposed on the bearing portion 17b of the carrier, and is spline-fitted to the other side gear 48 inside the case 20. A drive shaft (not shown) is connected to each side gear shaft 14.

A wear-resistant layer 52 is interposed between the inner peripheral surface of the boss portion 21a of the case 20 and the outer peripheral surface of one side gear shaft 14. The wear-resistant layer 52 is made of a bearing alloy, oil-impregnated sintered alloy or other metal, nylon, polytetrafluoroethylene or other resin with a low coefficient of friction. The wear-resistant layer 52 is formed in the shape of a bush, and is press-fitted into the boss portion 21a of the case 20, or coated on the inner circumferential surface of the boss portion 21a or the outer circumferential surface of the side gear shaft 14.

(Operation of the embodiment) The ring gear 24 of the differential gear device 12 incorporated in the vehicle meshes with a pinion (not shown) and receives power. When the ring gear 24 rotates, the case 20 and the pair of side gear shafts 14 rotate, and power is transmitted to the drive shaft.

The lubricating oil contained in the carrier 16 is splashed up by the rotation of the ring gear 24, passes through the supply hole 26 on the one hand, and the supply hole 28 on the other hand.
This leads to a space surrounded by the washer 33 and the oil seal 50. Thereafter, it is guided to each rolling bearing by the pump action of the rolling bearing, that is, the suction action by centrifugal force.

The lubricating oil that has reached the rolling bearing 18 is blown away by centrifugal force and collects inside the outer race 32. It is attached to the roller 34 and guided to the inner race 30, and reaches the wear-resistant layer 52 from the oil hole 36 of the inner race 30, through the annular groove 38 and oil hole 40 of the case boss 21a, and reaches the wear-resistant layer 52.
The sliding parts between the side gear shaft 14 and the side gear shaft 14 are lubricated.

As in the illustrated embodiment, the rolling bearing 18 is a tapered roller bearing, and the inner race 3
When the oil hole 36 of No. 0 is located inside the case 20, the largest amount of lubricating oil gathers in the portion of the outer race 32 corresponding to the oil hole 36, so the amount of lubricating oil guided to the oil hole 36 increases accordingly. Even better lubrication can be achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a final reduction differential gear device incorporating the lubrication structure according to the present invention, and FIG. 2 is an enlarged sectional view of the main parts. 10...Lubrication structure, 12...Differential gear device, 1
4...Side gear shaft, 16...Carrier,
17a, 17b... Bearing portion, 18, 22... Rolling bearing, 20... Case, 21a, 21b...
Boss portion, 26, 28... Supply hole, 30... Inner race, 32... Outer race, 34... Roller, 36, 40... Oil hole, 52... Wear-resistant layer.

Claims (1)

[Scope of utility model registration request] A lubrication structure for a final reduction gearing device in which a side gear shaft extends through a bearing portion of a carrier,
It has an inner race provided with an oil hole penetrating in the radial direction, and has a rolling bearing mounted on the bearing portion of the carrier, and a boss portion through which the side gear shaft is provided with an oil hole penetrating in the radial direction. a case in which the boss part is fitted to the inner race so that the oil hole in the boss part communicates with the oil hole in the inner race; an outer peripheral surface of the side gear shaft and an inner peripheral surface of the boss part of the case; and a wear-resistant layer interposed between the lubricating structure of the final reduction gear.