JPH08247155A - Sealing structure of final reduction gear - Google Patents

Abstract

PURPOSE: To prevent lubricating oil from the bearing side, from flowing out to the outside by disposing an oil seal between the extending part of the inner race of a bearing supported on a sleeve and the sleeve. CONSTITUTION: A drive pinion 41 is supported on a sleeve 45 through a taper roller bearing 43. The inner race 49 of the taper roller bearing 43 is extended onto a companion flange 53 side to form an extending part 49a with the absence of a roller 51. An oil seal 59 is disposed between the extending part 49a and the sleeve 45. The oil seal 59 is provided with seal lips 59a, 59b brought into contact with the outer periphery of the extending part 49a of the inner race 49 and a seal lip 59c brought into contact with the side of a dust shield 61. This sealing structure inhibits lubricating oil from reaching a contact part 53a with the inner race 49 of the companion flange 53, thus preventing lubricating oil from flowing out to the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a final reducer for an automobile, and more particularly to a seal structure for a final reducer for sealing outflow of lubricating oil from a bearing supporting a drive pinion to the outside.

[0002]

2. Description of the Related Art Generally, in an automobile such as a truck, a final reduction gear is arranged for decelerating an input torque that has been shifted by a transmission and has passed through a propeller shaft and for converting a rotational speed and a rotational direction and transmitting the same to a drive shaft. Has been done.
FIG. 2 shows this type of final reduction gear. In this final reduction gear, the rotation from a propeller shaft (not shown) is input to the companion flange 11, and the rotation of the companion flange 11 causes the drive pinion 13 to rotate. ,
It is transmitted to the drive gear 17 on the differential device 15 side.

FIG. 3 shows the details of the support portion of the drive pinion 13 in this type of final reduction gear. The drive pinion 13 is supported by the sleeve 21 via the tapered roller bearing 19. A companion flange 15 is spline-fitted to the drive pinion 13 and fixed by a nut 23.

The companion flange 15 is in contact with the inner race 25 of the tapered roller bearing 19, and an oil seal 29 is arranged outside the contact portion 27. A dust shield 31 is arranged on the companion flange 15 side of the oil seal 29.

An O-ring 33 is arranged between the end of the drive pinion 13 and the companion flange 15. In the above-mentioned support structure, the outflow of the lubricating oil from the bearing 19 side is sealed by the oil seal 29, and the lubricating oil passing through the contact portion 27 of the companion flange 15 with the inner race 25 is discharged to the outside. The outflow of is sealed by the O-ring 33.

[0006]

However, in such a conventional seal structure for the final reduction gear, the lubricating oil is prevented from flowing out through the contact portion 27 of the companion flange 15 with the inner race 25. Therefore, it is necessary to dispose the O-ring 33 between the end of the drive pinion 13 and the companion flange 15, which causes a problem of increasing the number of parts and the number of assembling steps.

Further, in order to prevent abrasion of the contact portion 27 of the companion flange 15 to the inner race 25 or the contact portion 35 to the oil seal 29, these contact portions 27 of the companion flange 15 are There is a problem that 35 needs to be hardened by, for example, induction hardening. Further, since the companion flange 15 is spline-fitted to the drive pinion 13, there is a problem that the runout is relatively large and the performance of the oil seal 29 is deteriorated.

The present invention has been made in order to solve the above conventional problems, and an object thereof is to provide a seal structure for a final reduction gear, which has a simple structure and can greatly improve the sealing property as compared with the conventional structure. To do.

[0009]

According to a first aspect of the present invention, there is provided a seal structure for a final reduction gear, wherein a companion flange is fitted and fixed to a drive pinion supported by a sleeve through a bearing, and external lubrication oil from the bearing is externally applied. In the sealing structure of the final reduction gear in which the outflow to the oil seal is sealed by an oil seal, the inner race of the bearing is extended to the companion flange side, and the oil seal is provided between the extending portion and the sleeve. Is arranged.

[0010]

According to the seal structure of the final reduction gear of the first aspect, the inner race of the bearing is extended to the companion flange side, and the oil seal disposed between the extended portion and the sleeve prevents the inner race from the bearing side. The lubricating oil is prevented from flowing out.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an embodiment of a seal structure for a final reduction gear according to the present invention, in which reference numeral 41 denotes a drive pinion. This drive pinion 41
Through the taper roller bearing 43
It is supported by 5. The taper roller bearing 43 is
A roller 51 is arranged between the outer race 47 and the inner race 49.

A companion flange 53 is fitted to the drive pinion 41 with a spline 55 and a nut 57.
It is fixed by. One end surface of the companion flange 53 is in contact with the inner race 49 of the tapered roller bearing 43.

In this embodiment, the inner race 49 of the taper roller bearing 43 has the companion flange 5
An extension portion 49a extending to the third side and having no roller 51
Are formed. An oil seal 59 is arranged between the extending portion 49a and the sleeve 45.

A dust shield 61 is arranged on the oil seal 59 side of the companion flange 53. The oil seal 59 has an extending portion 49a of the inner race 49.
First and second seal lips 59 that abut the outer circumference of the
It has a and 59b, and a third seal lip 59c that comes into contact with the side surface of the dust shield 61.

In the seal structure of the final reduction gear described above, the oil seal 59 arranged between the extending portion 49a of the inner race 49 and the sleeve 45 causes the lubricating oil from the taper roller bearing 43 side to flow out. Is prevented. Then, in the seal structure of the final reduction gear configured as described above, the inner race 49 of the taper roller bearing 43 extends toward the companion flange 53 side and is arranged between the extending portion 49 a and the sleeve 45. The oil seal 59 allows the tapered roller bearing 4
Since the lubricating oil from the 3 side is prevented from flowing out, the sealability can be greatly improved with a simple structure as compared with the conventional case.

That is, in the seal structure of the final reduction gear described above, the inner race 4 of the taper roller bearing 43 is used.
9 extends to the companion flange 53 side, and the oil seal 59 is arranged between the extending portion 49a and the sleeve 45, so that the lubricating oil reaches the contact portion 53a of the companion flange 53 to the inner race 49. As a result, there is no need to arrange an O-ring between the end of the drive pinion and the companion flange as in the conventional case, and the number of parts and the number of assembly steps can be reduced.

Further, since the lubricating oil does not reach the contact portion 53a of the companion flange 53 with the inner race 49, the wear of the contact portion 53a does not lead to the leakage of the lubricating oil, which is different from the conventional case. It is not necessary to harden the contact portion of the companion flange to the inner race by, for example, induction hardening. Since the oil seal 59 does not come into contact with the companion flange 53, it is not necessary to cure the companion flange 53 by induction hardening, for example, in order to prevent abrasion of the contact portion with the oil seal 59 as in the conventional case.

Further, the extending portion 49a of the inner race 49 of the taper roller bearing 43 having a relatively small runout.
In addition, since the oil seal 59 is brought into contact with the oil seal 59, the performance of the oil seal 59 can be improved as compared with the case where the oil seal 59 is brought into contact with the companion flange having a relatively large shake.

[0020]

As described above, in the seal structure of the final reduction gear of the present invention, the inner race of the bearing is extended to the companion flange side, and the oil disposed between the extended portion and the sleeve is arranged. Since the seal prevents the lubricating oil from flowing out from the bearing side,
There is an advantage that the sealability can be greatly improved with a simple structure.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a seal structure for a final reduction gear according to the present invention.

FIG. 2 is a cross-sectional view showing a final reduction gear.

FIG. 3 is a sectional view showing a seal structure of a conventional final reduction gear.

[Explanation of symbols]

 41 Drive Pinion 43 Tapered Roller Bearing 45 Sleeve 49 Inner Race 49a Extension 53 Companion Flange 59 Oil Seal

Claims (1)

[Claims] 1. A seal of a final reduction gear, wherein a companion flange is fitted and fixed to a drive pinion supported by a sleeve via a bearing, and the outflow of lubricating oil from the bearing is sealed by an oil seal. In the structure, the inner race of the bearing is extended toward the companion flange side, and the oil seal is arranged between the extending portion and the sleeve, and the seal structure of the final reduction gear is characterized. .