JP2579496Y2 - 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 more particularly to a sealing device having a backup ring.

[0002]

2. Description of the Related Art As a conventional sealing device of this type, for example, there is one as shown in FIG. That is, in the sealing device 100, the lip tip 103 of the annular seal lip 102 formed integrally with the reinforcing ring 101 is brought into sealing contact with the outer peripheral surface of the movable shaft 105 by the spring 104, and the fluid on the fluid side O to be sealed is placed on the atmosphere side. A is configured not to leak. The inner peripheral surface of the seal lip 102 and the reinforcing ring 101
The backup ring 107 is attached to the holder 106 formed by the above-described method, and when the pressure from the fluid O to be sealed is generated, it is possible to prevent the deterioration of the sealing performance caused by the deformation of the seal lip 102.

[0003]

However, in the case of the above-mentioned prior art, since the backup ring 107 is shaped to hold the axial movement by the reinforcing ring 101, the backup ring 107 and the reinforcing ring 101 Resistance on the contact surface with the shaft, and it is difficult to follow the eccentricity of the shaft (especially when moving to the outer diameter side and trying to return to the inner diameter side). .

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a sealing device capable of improving the eccentricity of a backup ring.

[0005]

In order to achieve the above object, according to the present invention, a seal lip for sealingly contacting the outer peripheral surface of a movable shaft, and the seal lip is held when the seal lip is pressurized. the sealing device consisting of a backup ring, the holder for mounting the backup ring provided in the sealing lip, the backup ring and e
A plurality of notches provided on one of the
The ribs that are arranged on the other side facing the
The contact surface is provided with an interference , and the interference and the rib
And an elastic backup ring supporting portion having an elastic force for urging in a radial direction is provided.

[0006]

In the sealing device having the above-mentioned structure, the elastic backup ring supporting portion having the elastic force for biasing in the radial direction attempts to return to the original state by the elastic force when the backup ring is pushed in due to the shaft eccentricity. Power works, and followability improves.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. 1 to 4 showing a sealing device according to an embodiment of the present invention, reference numeral 1 denotes an annular seal lip integrally formed with a reinforcing ring 3 fitted on the inner periphery of a housing 2, and the seal lip 1 is made of rubber or the like. Of the elastic material. A lip tip 4 having a wedge-shaped cross section provided on the inner peripheral side of the seal lip 1 is in sealing contact with the outer peripheral surface of the movable shaft 5 so that the fluid in the fluid side O to be sealed does not leak from the movable shaft 5 side to the atmosphere side A. Is configured. The fitting surface between the inner peripheral surface of the housing 2 and the seal lip 1 is also in a sealed state. A spring 6 is mounted on the outer peripheral surface of the lip tip 4 and presses the lip tip 4 toward the movable shaft 5.

An annular backup ring 8 is mounted in a holder 7 formed by the inner peripheral surface of the seal lip 1 near the atmosphere side A and the end surface of the reinforcing ring 3 extending toward the movable shaft 5 on the fluid side O to be sealed. Have been. On the outer peripheral side of the backup ring 8, a cut-out portion 81 such as a petal is provided. The notch 81 has a concave shape as shown in FIG. 3A when viewed in a transverse section, and has a substantially rectangular surface on the side of the non-movable shaft 5 as shown in FIG. The shape of the portion that is not notched is a shape along the inner peripheral surface of the holder 7 of the seal lip 1 as shown in FIG. 3C. Further, the end face of the notch portion 81 on the side of the reinforcing ring 3 protrudes toward the reinforcing ring 3 in the axial direction from the end face of the notched portion on the side of the reinforcing ring 3. The notch 81 forms a groove 82 equally spaced from the contact surface with the reinforcing ring 3 between the protruding portions. In addition, the backup ring 8 is attached to the lip tip 4 on the fluid side O to be sealed.
Is applied to prevent the lip tip 4 from deforming in the direction of the atmosphere side A when the pressure is applied, thereby preventing the sealing property between the lip tip 4 and the movable shaft 5 from deteriorating. I have.

On the other hand, ribs 9 equidistant from the seal lip 1 are formed on the inner peripheral surface of the holder 7 of the seal lip 1 by an elastic material such as rubber. The surface of the rib 9 on the side of the backup ring 8 has a shape along the outer peripheral surface of the notch 81 of the backup ring 8, and has a width substantially equal to the width of the notch 81 of the backup ring 8. . The notch 81 of the backup ring 8
Then, the backup ring 8 is mounted in the holder 7 so that the rib 9 in the holder 7 of the seal lip 1 is fitted. At this time, a contact B between the notch portion 81 and the rib 9 is designed to have an interference, and the elastic backup having an elastic force to urge in a radial direction by the interference and the rib 9 of the elastic material. The ring support 10 is provided.

In the sealing device having the above-described structure, the elastic ring that urges the backup ring 8 in the radial direction when the backup ring 8 is pushed in due to the axial eccentricity is formed by the interference as the elastic backup ring support portion 10 and the rib 9. The force to return to the original works, and the followability is improved.

Further, the frictional force between the reinforcing ring 3 and the backup ring 8 is reduced by the grooves 82 formed between the notches 81, which helps to improve the followability.

In the above embodiment, the holder 9 of the seal lip 1 is formed by the inner peripheral surface of the seal lip 1 and the reinforcing ring 3 as an example. Can be applied to

[0013]

The present invention has the above-described structure and operation. Since the elastic backup ring support portion is provided in the holder, the elasticity that urges the backup ring in the radial direction when the backup ring is pushed in due to the shaft eccentricity. Since the force to return to the original state is exerted by the force, the followability is improved, and accordingly, a stable sealing property is obtained.

[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 main part of the sealing device of FIG. 1;

3 (a) is a sectional view taken along line XX of the main part of the sealing device of FIG. 2, and FIG. 3 (b) is a sectional view taken along line YY of the backup ring of FIG. 3 (a). (C) is the same as (a) in FIG.
FIG. 3 is a sectional view taken along line ZZ of the backup ring of FIG. FIG. 4D is a partially cutaway perspective view of a main part of the backup ring.

FIG. 4 is a longitudinal sectional view of a main part showing a rib.

5 (a) is a longitudinal sectional view of a conventional sealing device, and FIG. 5 (b) is a longitudinal sectional view of a main part of FIG. 5 (a).

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 seal lip 2 housing 3 reinforcing ring 4 lip tip 5 movable shaft 6 spring 7 holder 8 backup ring 81 notch 82 groove 9 rib 10 elastic backup ring support

Claims (1)

(57) [Scope of request for utility model registration] 1. A seal lip for sealingly contacting the outer peripheral surface of a movable shaft, a backup ring for holding the seal lip when pressed, and a holder for mounting the backup ring provided on the seal lip. Of the backup ring and the holder,
And a plurality of notches to be provided on the other side facing the notches.
With the rib to be set on the radial contact surface with interference.
Only, sealing device, characterized in that with consisting of the rib and white the tightening and an elastic back-up ring supporting portion having an elastic force for urging the radial direction.