JPH083760Y2 - Sealing device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sealing device used for, for example, a rod seal of a power steering of an automobile, and more particularly to a sealing device provided with a backup ring for backing up a seal lip.

(Prior Art) As a conventional sealing device of this type, for example, there is one shown in FIG. That is, this sealing device 100
Is to seal a gap between the housing 101 and a movable shaft 103 which is inserted into the shaft hole 102 of the housing 101 so as to be relatively movable.

The sealing device 100 includes a metal ring 104 fitted to the inner circumference of the shaft hole 102 of the housing 101, and a rubber-like elastic body 106 integrally baked and fixed to the metal ring 104. The rubber-like elastic body 106 extends toward the sealed fluid side in the axial direction and has a movable shaft 1 at its tip.
03 A sealing lip 105 is provided in sealing contact with the surface.

Then, in order to support the pressure of the sealing fluid applied to the seal lip 105, a pressure resistance is enhanced by interposing a resin-made backup ring 108 in the gap with the movable shaft 103.

Further, the anti-sealing fluid side end surface 108b of the backup ring 108 is supported by being brought into close contact with the sealing fluid side end surface 110a of the reinforcing flange 110 extending inward in the radial direction from one end of the metal ring 104.

(Problems to be Solved by the Invention) However, in the case of the above-mentioned conventional technique, no measures are taken to prevent foreign matter from entering from the anti-sealing fluid side, that is, the atmosphere side, and the backup ring 108 is caused by foreign matter entering. There is a possibility that foreign matter may be caught in the sliding surface of the seal lip 105 and the sliding surface of the seal lip 105, and the sliding surface may be scratched, and the sealing fluid such as oil may leak out.

Therefore, it may be considered to provide a dust lip at the inner end portion of the reinforcing flange 110 of the metal ring 104 to prevent foreign matter from entering from the atmosphere side.

However, when a dust lip is provided at the end portion of the reinforcing flange 110 on the sealed fluid side, the end surface 110a of the reinforcing flange 110 on the sealed fluid side has an atmosphere-side end surface 1 of the backup ring 108.
Since 08b is in close contact, the rubber-like elastic body 106 and the dust lip are discontinuously isolated from each other, and the molding material does not enter the dust lip at the time of molding, resulting in a problem of poor moldability. .

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a sealing device which prevents foreign matter from entering and has excellent moldability.

(Means for Solving the Problem) In order to achieve the above object, in the present invention, a gap between a housing and a movable shaft that is relatively movably inserted into a shaft hole of the housing is sealed. And a metal ring fitted to the inner circumference of the shaft hole of the housing, and a seal lip that is integrally baked on and fixed to the metal ring and extends toward the axial sealing fluid side and has a tip sealingly contacting the movable shaft surface. And a rubber-like elastic body having a rubber-like elastic body, and a resin-made backup ring is interposed in the gap between the seal lip and the movable shaft. In a sealing device, which is supported in close contact with a sealing fluid side end surface of a reinforcing flange extending inward from one end in a radial direction, a plurality of radially extending grooves are circumferentially provided on a sealing fluid side surface of the reinforcing flange. A dust lip made of a rubber-like elastic body extending axially in the sealed fluid side is integrally formed with the rubber-like elastic body that is baked and fixed to the reinforcing flange through the groove, and is integrally formed with the inner end of the reinforcing flange of the metal ring. It is characterized by being provided.

(Operation) In the sealing device having the above configuration, the dust lip prevents foreign matter from entering the sliding surface between the backup ring and the movable shaft and the sliding surface between the seal lip and the movable shaft.

Further, the molding material flows around to the dust lip side through the groove provided on the side surface of the reinforcing flange on the sealed fluid side, so that the rubber-like elastic body and the dust lip can be simultaneously molded.

(Example) Below, this invention is demonstrated based on the Example shown in figure.
1 and 2 showing a sealing device according to an embodiment of the present invention, reference numeral 1 denotes the entire sealing device. As in the conventional example, the housing 2 and the shaft hole 3 of the housing 2 are placed relative to each other. A gap between the movable shaft 4 and the movable shaft 4 is inserted so as to be freely movable.

The sealing device 1 includes a rubber-like elastic body 7 having a metal ring 5 and a seal lip 6 integrally fixed to the metal ring 5 by baking.
And a backup ring 13 made of resin interposed in the gap between the seal lip 6 and the movable shaft 4.

The metal ring 5 is an annular member having an L-shaped cross section,
The outer cylindrical portion 8 is fitted and fixed to the inner circumference of the shaft hole 3, and the reinforcing flange 9 extends inward in the radial direction from the end of the outer cylindrical portion 8 on the side opposite to the sealed fluid.

The rubber-like elastic body 7 includes an outer peripheral rubber portion 10 adhered and fixed to an outer peripheral portion of the outer peripheral portion 8 of the metal ring 5, an inner peripheral portion of the outer cylindrical portion 8 and a reinforcing flange 9.
It is composed of an axially thick inner peripheral rubber portion 11 which is integrally baked on both of the sealing fluid side end surfaces 9a of the inner peripheral rubber portion 11a of the inner peripheral rubber portion 11a. The seal lip 6 extends. A spring 12 is attached to the outer periphery of the lip tip portion 61 of the seal lip 6 for applying a tightening force.

The backup ring 13 has a rectangular shape with a substantially horizontal cross section, and an outer peripheral surface thereof is a taper surface which is inclined so as to have a gradually smaller diameter toward the sealing fluid side O in the axial direction. The inner peripheral surface is slidably in close contact with the surface of the movable shaft 4. The end 13a of the backup ring 13 on the sealed fluid side is engaged with the jaw of the lip tip 61 of the seal lip 6, while the atmosphere side end surface 13b of the backup ring 13 is perpendicular to the movable shaft 4. The inner end portion of the reinforcing flange 9 is in close contact with the outer diameter side end portion of the end surface 13b over the entire circumference.

A dust lip 14 made of a rubber-like elastic material is provided at the inner end of the reinforcing flange 9 and extends to the side A opposite to the axially sealed fluid. The dust lip 14 extends obliquely in a direction in which the diameter becomes gradually smaller toward the atmosphere side in the axial direction, and a lip tip portion 61 of the dust lip 14 slidably and sealingly contacts the surface of the movable shaft 4. .

The end surface 15 of the root portion 15 of the dust lip 14 is formed to be flush with the end surface 9a of the reinforcing flange 9 on the sealing fluid side.

A plurality of grooves 16 are provided in the circumferential direction on the side surface of the reinforcing flange 9 on the side of the sealed fluid so that the dust lip 14 and the inner peripheral rubber portion 11 of the rubber-like elastic body 7 communicate with each other.

In this embodiment, a plurality of grooves 16 are equally arranged in a petal shape, and are formed on the surface of the reinforcing flange 9 by pressing.

At the time of molding, the molding material flows through the groove 16 and the rubber-like elastic body 7 and the dust lip 14 are simultaneously molded integrally.

In the sealing device having the above structure, the sealing fluid is the movable shaft 4
Sealing is performed by the seal lip 6 which is in sliding contact with the surface, and the pressure of the sealing fluid acting on the seal lip 6 is taken up by the backup ring 13 to enhance the pressure resistance.

The dust lip 14 prevents dust from entering from the atmosphere side A to the sliding surface of the backup ring 13 and the seal lip 6 with the movable shaft 4, and protects the sliding surface to provide a good seal for a long time. Performance can be secured.

Also, when molding the sealing device 1, the molding material is
16 through the sealing fluid side O of the reinforcing flange 9 to the atmosphere side A
Flow into the inner ring rubber part 11 and the dust lip on the inner ring side of the metal ring 5.
14 and 14 can be integrally molded at the same time. At the time of molding, even when the backup ring 13 is inserted, the molding material can flow through the groove 16, so that the backup ring 13 can be integrally molded.

(Effects of the Invention) The present invention has the above-described structure and operation, and by providing the dust lip, the sliding surface between the backup ring and the movable shaft and the sliding surface between the seal lip and the movable shaft are reduced. Foreign matter is prevented from entering.

Further, since the molding material can be made to wrap around to the dust lip side through the groove provided on the side surface of the reinforcing flange on the sealed fluid side, the rubber-like elastic body and the dust lip can be simultaneously molded, and the moldability is improved. You can

Further, the dust lip is a rubber-like elastic body, and the seal lip and the dust lip are provided on the sealing fluid side surface and the anti-sealing fluid side surface of the reinforcing flange of the metal ring, respectively, and a plurality of them extend in the radial direction of the sealing fluid side surface. Since the seal lip and the backup ring are not integrally transferred to the dust lip by integrally forming the seal lip and the backup ring, the sealability of the seal lip and the dust lip can be kept constant.

[Brief description of drawings]

1 is a longitudinal sectional view of a main part of a sealing device according to an embodiment of the present invention, FIG. 2 is a sectional view of the main part taken along line II-II of FIG. 1, and FIG.
The figure is a longitudinal sectional view of a main part of a conventional sealing device. DESCRIPTION OF SYMBOLS 1 ... Sealing device, 2 ... Housing 3 ... Shaft hole, 4 ... Movable shaft 5 ... Metal ring, 6 ... Seal lip 7 ... Rubber-like elastic body, 8 ... Outer cylinder part 9 ... Reinforcing flange, 9a ... Sealing fluid Side end face 10 ... Outer peripheral rubber portion, 11 ... Inner peripheral rubber portion 12 ... Spring, 13 ... Backup ring 14 ... Dustrip, 15 ... Base portion 16 ... Groove

Claims (1)

[Scope of utility model registration request] 1. A metal ring which seals a gap between a housing and a movable shaft which is inserted into a shaft hole of the housing so as to be relatively movable, and a metal ring which is fitted to an inner circumference of the shaft hole of the housing. A rubber-like elastic body provided with a seal lip that is integrally baked on and fixed to the metal ring and extends toward the axially sealed fluid side and has a tip sealingly contacting the surface of the movable shaft, the seal lip and the movable shaft. Sealing device in which a resin-made backup ring is interposed in the gap between the backup ring and the end face on the anti-sealing fluid side of the backup ring in close contact with the end face on the sealing fluid side of the reinforcing flange extending inward in the radial direction from one end of the metal ring A plurality of radially extending grooves are provided in the circumferential direction on the side surface of the reinforcing flange on the sealed fluid side, and through the grooves, integrally with the rubber-like elastic body baked and fixed to the reinforcing flange, Metal ring A sealing device comprising a dust lip made of a rubber-like elastic body extending in the axial direction opposite to the sealing fluid side at the inner end of the reinforcing flange.