JPH07139612A - Deceleration device for vehicle - Google Patents

Abstract

PURPOSE:To prevent slipping-out of a sealing mechanism so as to prevent oil leakage and dust invasion by discharging pressure to another space even if the pressure of oil is increased by oscillation. CONSTITUTION:A space S1 inside an oil seal 6 and other space inside a differential carrier cover 1 are connected to each other by passages 11, 14 provided inside a spline shaft 10, and oil or air inside the space S1 is discharged to the other space S2, etc., so that the pressure in the space S1 may not increase by oscillation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speed reducer for a vehicle, and more particularly to a seal mechanism for a gap between a differential carrier cover and a yoke joint.

[0002]

2. Description of the Related Art Generally, in a vehicle equipped with an engine, a transmission, which is connected to the engine via a clutch or a torque converter, is supported on a vehicle body frame via a vibration absorbing elastic body. On the other hand, the speed reducer is directly fixed to the vehicle body frame in a form separated from the transmission. The output gear of the transmission, the input gear of the speed reducer, and the input gear of the speed reducer are connected by a universal joint directly or via a propeller shaft.

[0003] A conventional speed reducer is, for example, the actual open sho 62-6.
As disclosed in Japanese Laid-Open Patent Publication No. 0023, an outer frame is formed by a differential carrier cover, and an input gear is rotatably supported inside the differential carrier cover via a bearing. As described above, since the transmission is not fixed to the machine base, the yoke joint that is integrally rotatably connected to the universal joint has a space that can slide in the axial direction and is spline-fitted to the input gear. As a result, the yoke joint rotates and slides in the input gear, thereby alleviating the transmission of vibrations from the transmission accompanying the rotation of the engine. The input gear is further fitted to the output gear, and the rotation of the yoke joint is decelerated and transmitted to the output gear via the input gear. In the most common speed reducer, an oil seal is provided between the yoke joint and the differential carrier cover as an oil seal as a seal mechanism having an oil lip and a dust lip for preventing oil leakage or dust intrusion. The space in which the yoke joint slides like this exists inside the oil seal.

[0004]

During operation of the speed reducer, air or oil exists in the space inside the oil seal in the differential carrier cover, and the pressure of the oil directly affected by the vibration of the yoke joint associated with the transmission is directly affected. It will be added to the oil seal. The oil seal is non-rotatable, and when a high pressure is applied to the oil seal, the oil lip and dust lip are pressed against the rotating yoke joint side, and the oil seal comes out. Alternatively, a problem such as intrusion of dust occurs.

In view of the above problems, it is an object of the present invention to provide a speed reducer for a vehicle which prevents oil leakage or dust invasion by making a pressure on the oil seal.

[0006]

According to the present invention, in order to solve the above problems, an output gear and an input gear fitted to the output gear and driven to rotate are disposed in a differential carrier cover.
A yoke joint that is fastened to a universal joint that transmits the rotation from the transmission to the input gear, and a seal mechanism between the yoke joint and the differential cover are provided, and a spline shaft provided in the yoke joint is the input gear. On the other hand, in the speed reducer for a spline-fitted vehicle, the spline shaft is provided with a passage that connects the space formed by the seal mechanism and the spline shaft and a different space in the differential carrier. The gist of the invention is to provide a vehicle speed reducer.

[0007]

In the structure of the present invention as described above, the yoke joint vibrates in the input gear in the axial direction together with the vibration of the transmission. At this time, pressure is applied to the air or oil existing in the space inside the oil seal, and the air or oil moves to another space through the passage formed through the spline shaft. This prevents the pressure inside the space inside the oil seal from rising.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of a vehicle speed reducer according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, the driving force of the engine is changed on the vehicle body frame (not shown) via a transmission 12 mounted adjacent to the engine, and finally the driving wheels are rotated. Differential 1 that transmits rotational force to the drive shaft for driving
Have three. Here, the transmission 12 and the differential 13 are connected by a universal joint 2 so that vibrations of the engine and the transmission 12 are absorbed and not transmitted. The universal joint 2 has one end (right side in the drawing) connected to the output shaft of the transmission 2, and the other end (left side in the drawing) connected to the yoke joint 3. Further, the yoke joint 3 is connected to the spline shaft 1 from the center thereof.
0 is projected, and is fitted to the input gear 4 supported by bearings 8 and 9 in the differential carrier cover 1. The input gear 4 meshes with the output gear 5, and finally transmits the driving force to the driving wheels of the vehicle. The diff carrier cover 1 is filled with oil for lubricating the transmission device incorporated therein.

The spline shaft 10 has a differential carrier cover 1
In detail, the configuration inserted in the oil seal 6 is inserted between the spline shaft 10 and the diff carrier cover 1, and an oil seal 6 having an annular oil lip 6a and a dust lip 6b is fitted inside the spline shaft 10 and the outside thereof. A seal stopper plate 7 formed in an annular disc shape is attached to the differential carrier cover 1 so as to face the outer surface thereof. The seal stopper plate 7 serves to prevent the oil seal 6 from falling off.

With the above structure, a space S1 sealed by the bearing 8, the oil seal 6 and the spline shaft 10 is formed. Also, the spline shaft 10
A space S2 surrounded by the bearing 9 and the differential carrier cover 1 is formed at the tip of the. The spaces S1 and S2
Are communicated with one passage 14 which is bored in the spline shaft 10 along the axial direction and a passage 11 which is communicated with the passage 14 and is bored in the radial direction of the spline shaft 10.

This embodiment is configured as described above, and
The operation will be described in detail. The rotation and vibration output from the transmission 12 by the drive of the engine are transmitted to the universal joint 2 and the yoke joint 3, and the yoke joint 3 rotates while vibrating slightly in the input gear 4 in the axial direction, thereby causing vibration. It is absorbed and only the rotational force is transmitted to the input gear 4. The input gear 4 is fitted to the output gear 5 with a predetermined gear ratio, and the rotational force of the input gear 4 is reduced and transmitted to the output gear 5.

As described above, the slight vibration of the yoke joint 3 is absorbed by the input gear 4, but is transmitted to the air or oil in the space S1 sealed by the oil seal 6, so that the pressure in the space S1 is reduced. Trying to rise. However, since the oil or air in the space S1 is discharged to the space S2 through the passage 11 and the passage 14, the pressure in the space S1 does not rise, and the oil leaks or dust enters the outside of the differential carrier cover 1. Prevent that.

Next, another embodiment will be described in detail with reference to FIG. 2. Since the other parts are the same as those of the above-mentioned embodiment,
The description is omitted. In FIG. 2, the spline shaft 10
One passage 15 is bored in the central portion thereof in the radial direction. Further, a passage 16 is formed at a position corresponding to the passage 15 in the radial direction of the input gear 4. That is, the passage 16 is a large space S3 in the differential carrier cover 1.
And the space S1 and the space S3 are formed to face the passage 1
1, the passage 14, the passage 15, and the passage 16 communicate with each other.

With the above-described structure, in this embodiment, in addition to the same effects as the above-mentioned embodiments, the oil or air in the passages 15 and 16 is positively generated by the centrifugal force generated by the rotation of the input gear 4. Since it is discharged into the relatively wide space S3, the increase in the pressure in the space S1 can be further suppressed. The present invention is not limited to the above-described embodiment, but it is possible to provide a plurality of passages formed in the spline shaft 10 and to set the space communicating with the space S1 to another space.

[0015]

As described in detail above, according to the present invention, the increase in the pressure in the space between the yoke joint sealed by the oil seal and the differential carrier cover is moderated, and the high pressure is not applied to the oil seal. Therefore, it is possible to maintain an appropriate pressure and prevent oil from leaking and dust from entering.

[Brief description of drawings]

FIG. 1 is a side sectional view of a vehicle speed reducer embodying the present invention.

FIG. 2 is a side sectional view of a main part of a vehicle speed reducer embodying the invention.

[Explanation of symbols]

1 ... Differential carrier cover, 2 ... Universal joint, 3 ... Yoke joint, 4 ... Input gear 5 ... Output gear, 6, 6a, 6b
... oil seal, 12 ... transmission, 11, 14, 15, 1
6 ... passage, S1, S2, S3 ... space

Claims (2)

[Claims] 1. A differential carrier cover is provided with an output gear and an input gear fitted to the output gear and driven to rotate, and fastened to a universal joint for transmitting rotation from a transmission to the input gear. A sealing mechanism for a vehicle, comprising: a yoke joint; and a sealing mechanism between the yoke joint and the differential cover, wherein a spline shaft provided in the yoke joint is spline fitted to the input gear. And a passage that connects a space formed by the spline shaft and a different space in the diff carrier to the spline shaft. 2. The speed reducer for a vehicle according to claim 1, wherein the passage communicates with a space formed by the seal mechanism and the spline shaft and a space adjacent to a tip of the spline shaft.