JP2601644Y2 - Sealing device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device used for, for example, a power steering rod of an automobile, and particularly to a device having a backup ring.

[0002]

2. Description of the Related Art As a conventional sealing device of this kind, for example, there is one as shown in FIG. That is, the sealing device 100 is provided with a movable shaft 10 which is assembled concentrically with each other.
A lip tip 105 of an annular seal lip 104 formed integrally with a reinforcing ring 103 fitted to the housing 102 is used to seal a gap between the housing 1 and the housing 102.
The outer peripheral surface of the movable shaft 101 is hermetically contacted by the spring 106 so that the fluid on the sealed fluid side O does not leak to the atmosphere side A.

[0003] A backup ring 107 is mounted on the inner peripheral surface of the seal lip 104 so that when pressure is generated from the sealing fluid side O, the sealing performance caused by deformation of the seal lip 104 can be prevented. Has become.

[0004]

However, there have been many high-pressure sealing devices 100 with the backup ring 107 configured as described above, which have been used in mass production for power steering rods and the like in each automobile manufacturer. In each case, the high pressure P is applied to the sealing lip 104
When the backup ring 107 is acted upon, the backup ring 107 is pressed and shrunk to the inner diameter side to hold the movable shaft 101, and as a result, the sliding friction between the movable shaft 101 and the lip tip 105 increases, or the movable shaft 101 This cuts off a minute oil film on the surface, resulting in poor lubrication, leading to a shortened seal life.

The present invention has been made to solve the above-mentioned problems of the prior art, and aims at extending the life of the seal and reducing the friction between the movable shaft and the seal lip. It is to provide a sealing device.

[0006]

In order to achieve the above object, according to the present invention, there is provided a seal lip which comes into sealing contact with the outer peripheral surface of a movable shaft, and the seal lip is pressurized by a high pressure sealing fluid. And a backup ring for holding the sealing fluid , wherein the inner peripheral surface of the backup ring has a surface roughness of 10 μm to 40 μm on the high pressure sealing fluid side and capable of storing the sealing fluid.
When the roughness majority Ru provided subjected to satin-like roughening process is
In both cases, a taper section with a diameter increasing toward the atmosphere side is installed on the atmosphere side.
And wherein the digit.

[0007]

In the sealing device having the above structure, the inner surface of the backup ring has a matte surface having a surface roughness of 10 μm to 40 μm.
Because having a roughness most subjected to Jo vandalism processing, the role of the high pressure acts on the sealing lip, when the back-up ring in the force is pressed against the movable shaft, roughness majority of the inner peripheral surface is an oil sump And an oil film is always kept between the movable shaft and the backup ring. As a result, good lubrication can be maintained, and the good lubrication also eliminates the cling of the backup ring to the movable shaft, thereby extending the seal life and reducing the friction between the movable shaft and the seal lip. Can be achieved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1 showing a sealing device according to an embodiment of the present invention, reference numeral 1 denotes a sealing device, which is an oil seal for a power steering rod of an automobile, and is a movable rod which is concentrically and relatively freely assembled with each other. The gap between the shaft 2 and the housing 3 is sealed.

The sealing device 1 generally includes a sealing lip 4
And a backup ring 5 provided on the inner periphery of the seal lip 4.

The seal lip 4 is annular and is formed of an elastic material such as rubber, and is provided integrally with a reinforcing ring 6 fitted on the inner periphery of the housing 3. A wedge-shaped lip tip 7 provided on the inner peripheral side of the seal lip 4
Is in sealing contact with the outer peripheral surface of the movable shaft 2 so that the fluid on the sealed fluid O side does not leak to the atmosphere side A. Further, a spring 8 is mounted on the outer peripheral side of the lip tip 7, and the spring 8 presses the lip tip 7 toward the movable shaft 2.

The reinforcing ring 6 is a cylindrical member having a flange 61 extending inward in the radial direction, and has an L-shaped cross section.
The rubber-like elastic body 9 is integrally provided on the outer peripheral surface of the cylindrical portion 62.

The cylindrical portion 62 of the reinforcing ring 6 is fitted and fixed to the inner peripheral surface of the housing 3 via the rubber-like elastic body 9, and the lip end of the seal lip 4 provided integrally with the reinforcing ring 6. 7 comes into sealing contact with the outer peripheral surface of the movable shaft 2 and is mounted between the housing 3 and the movable shaft 2.

An inner peripheral surface of the seal lip 4 near the atmosphere side A and a flange portion 61 of the reinforcing ring 6 extending toward the movable shaft 2.
And the end face of the sealed fluid side O of
Inside, an annular backup ring 5 is mounted.
This backup ring 5 is such that when pressure from the sealing fluid side O is applied to the lip tip 7, the lip tip 7 is deformed in the direction of the atmosphere side A, and the sealing property between the lip tip 7 and the movable shaft 2 is reduced. Has been prevented.

The inner peripheral surface of the backup ring 5 has a surface roughness of about 20 μm near the sealed fluid side O (10 to 10 μm).
A roughened portion 51 having a roughened surface (pear-skin shape) having a roughness of 40 μm is provided, and a tapered portion 52 extending from the large roughness portion 51 toward the atmosphere side A is provided.

In the sealing device having the above-described structure, the large roughness portion 51 is formed on the inner peripheral surface of the backup ring 5 and the atmosphere side A thereof.
Since the tapered portion 52 having the diameter increasing toward the atmosphere side A is provided, a high pressure acts on the seal lip 4 from the sealed fluid side O, and when the backup ring 5 is pressed against the movable shaft 2 by the force. The large roughness portion 51 functions as an oil pot for storing oil as a sealed fluid, and an oil film is always maintained between the movable shaft 2 and the backup ring 5, thereby improving lubricity.

Further, since the tapered portion 52 does not come into contact with the movable shaft 2, the contact width between the backup ring 5 and the movable shaft 2 is small and the oil film is not easily cut off, so that poor lubrication does not occur.

Further, since the diameter of the tapered portion 52 is increased toward the atmosphere side A, the oil is transferred to the sealed fluid side O.
Lip end 7 and the backup ring 5 can maintain good lubricity.

As described above, the lubricating property can be kept good, and the better lubricating property prevents the backup ring 5 from clinging to the movable shaft 2. The friction between the lip tips 7 could be reduced.

Although the above embodiment has been described with respect to an example in which the tapered portion 52 is provided on the inner peripheral surface of the backup ring 5, even if the tapered portion is not provided, the lubricating property is higher than that of the prior art. Therefore, the taper may not be provided. .

[0020]

[Effects of the Invention] The present invention has the above configuration and operation, and has a surface roughness of 1 on the inner peripheral surface of the backup ring.
Since a large roughness with a satin-like roughening of 0 μm to 40 μm is provided, the high pressure acts on the seal lip, and when the backup ring is pressed against the movable shaft by the force, the roughness of the inner peripheral surface is increased. The part plays the role of oil retaining, and always keeps an oil film between the movable shaft and the backup ring. As a result, good lubrication can be maintained, and since the good lubrication does not cause the backup ring to cling to the movable shaft, the life of the seal is extended and the friction between the movable shaft and the seal lip is reduced. Reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a sealing device according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of a conventional sealing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing device 2 Movable shaft 3 Housing 4 Seal lip 5 Backup ring 51 Large roughness part 52 Tapered part 6 Reinforcement ring 61 Flange part 62 Cylindrical part 7 Lip tip 8 Spring 9 Rubber elastic body 10 Holder

Claims (1)

(57) [Scope of request for utility model registration] 1. A sealing device having a seal lip that sealingly contacts an outer peripheral surface of a movable shaft and a backup ring that holds the seal lip when the seal lip is pressurized by a high-pressure sealing fluid. The surface has a surface roughness of 10 μm to 40 μm on the high pressure sealing fluid side, on which the sealing fluid can be stored.
When the roughness majority Ru provided subjected to satin-like roughening process is
In both cases, a taper section with a diameter increasing toward the atmosphere side is installed on the atmosphere side.
Sealing device, characterized in that digit.