JP2000193096A - Sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device to improve sealability and durability. SOLUTION: An annular gap between a shaft 2 and a housing 3 which are assembled concentrically to each other is sealed in a reciprocating manner and a seal member 7 is provided to have a lip part 7A arranged on the seal fluid side 5 of a bearing 4 and extending to the seal fluid side 5 and brought into slidable seal contact with the shaft 2. In a so formed sealing device, a bearing 4 is axially protruded and provided with an annular protrusion 4A supporting the lip part 7A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device such as an oil seal used for a shaft sealing portion of various devices.

[0002]

2. Description of the Related Art Conventionally, as this type of sealing device, for example, there is one as shown in FIG. That is, the sealing device 100 is a gas stay seal in which the high-pressure gas 200 is sealed, and seals an annular gap between the piston rod 101 and the tube cylinder 102 as two members that are assembled concentrically with each other.

[0003] The sealing device 100 includes a piston rod 1 provided on one opening side of a tube cylinder 102.
01 is fixed to an end face of a cylindrical bush 103 for closing an opening of the bush 103, and a flat washer-shaped metal ring 104 attached to the end face of the bush 103;
04, a sealing member 105 fixed to the sealed fluid side by baking
And

The seal member 105 is a so-called U packing, and its outer peripheral side lip 105B is
The inner peripheral side main lip 105A slidably contacts the outer peripheral surface of the piston rod 101 and seals the inner peripheral side with the sliding surface. .

[0005]

However, when the pressure of the high-pressure gas 200 is increased and the piston rod 101 moves in the direction A, excessive deformation of the main lip 105A as shown in FIG. Will happen.

When the piston rod 101 reciprocates, the excessive deformation of the main lip 105A is repeated every time the piston rod 101 moves in the direction A.
As shown in FIG. 4B, there has been a problem that the main lip 105A is cracked and broken.

SUMMARY OF THE INVENTION 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 sealing performance and durability.

[0008]

According to the present invention, in order to achieve the above object, an annular gap between a shaft and a housing, which are assembled concentrically with each other, is reciprocally sealed. In a sealing device having a sealing member disposed on a fluid side and having a lip portion extending toward a sealing fluid side and slidably sealingly contacting the shaft, the bearing projects in the axial direction to support the lip portion. And a ring-shaped projection.

Therefore, the bearing does not require other parts, and can prevent shaft eccentricity and excessive deformation of the lip portion of the seal member. The part is supported by contacting the annular projection protruding in the axial direction, preventing excessive deformation of the lip part, preventing cracks and breaks in the lip part due to repeated excessive deformation, and sealing performance In addition, the durability can be improved.

A seal member having a lip portion which slidably and sealingly contacts one of the two members, the seal member movably sealing an annular gap between the two members which are assembled concentrically with each other; And a reinforcing ring for reinforcing the sealing member, wherein the reinforcing ring has a support portion for supporting the lip portion on a surface on a sealed fluid side.

Therefore, the reinforcing ring can prevent the lip portion from being excessively deformed together with the reinforcement of the seal body, and the lip portion is supported by the support portion on the sealing fluid side surface of the sealing member, and the lip portion is excessively deformed. To prevent the occurrence of cracks or breaks in the lip portion due to repeated excessive deformation, thereby improving the sealing performance and durability.

[0012]

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the dimensions of the components described in this embodiment,
The material, shape, relative arrangement, and the like are not intended to limit the scope of the present invention only to them unless otherwise specified.

(First Embodiment) In FIG. 1 showing a sealing device according to a first embodiment, reference numeral 1 denotes a sealing device. The sealing device 1 is used as a seal for a gas stay, and seals an annular gap between a piston rod 2 as a shaft and a tube cylinder 3 as a housing, which are assembled concentrically with each other.

In the gas stay structure used in the present embodiment, a piston rod 2 is coaxially inserted reciprocally into a tube cylinder 3 having both ends opened. A slidable body piston is fixed to the inner peripheral surface of the tube cylinder 3, and the inside of the tube cylinder 3 is divided into two chambers by this body piston. It has become.

A bush 4 as a cylindrical bearing is provided at the open end of the tube cylinder 3 on the piston rod 2 side.
Are fixed by caulking to close an opening between the piston rod 2 and the tube cylinder 3. On the other hand, the open end of the tube cylinder 3 on the opposite side is closed by a cap.

A high-pressure gas 5 is sealed between the bush 4 of the tube cylinder 3 and the cap. The high-pressure gas 5 is sealed on both sides of the two chambers of the body piston through orifices of the body piston.

A sealing device 1 is mounted on the sealing fluid side (high-pressure gas 5 sealing side) of the bush 4 of the gas stay structure having the above configuration.
Is attached.

The sealing device 1 includes a metal ring 6 in the shape of a flat washer, and a seal member 7 fixed to the metal ring 6 by baking.

The seal member 7 is fixed to the metal ring 6 by baking with one end face of the metal ring 6 exposed, and the exposed end face of the metal ring 6 is brought into contact with the end face of the bush 4 on the sealed fluid side. Will be arranged.

The shape of the seal member 7 is a so-called U packing, and its outer peripheral lip 7B extends to the sealed fluid side, closely contacts the inner peripheral surface of the tube cylinder 3, seals the outer peripheral side, and forms an inner peripheral lip. The side main lip 7A extends toward the sealed fluid side and slidably contacts the outer peripheral surface of the piston rod 2 to seal the inner peripheral side.

Here, an annular projection 4A is provided on the inner peripheral side of the side face of the sealing fluid of the bush 4. The annular projection 4A projects axially between the main lip 7A of the seal member 7 and the piston rod 2.

In the sealing device 1 having the above structure, the bush 4 has an annular projection 4A, and the annular projection 4A projects axially between the main lip 7A of the sealing member 7 and the piston rod 2, and the main lip 7A Since excessive deformation is restricted, even when the piston rod 2 moves in the direction A, the main lip 7A is supported by the annular projection 4A to prevent excessive deformation, and the main lip 7A is cracked or damaged. Is prevented from occurring.

Therefore, the durability of the main lip 7A can be improved, and the sealing performance and the durability of the sealing device 1 can be improved.

Further, the bush 4 prevents eccentricity of the piston rod 2 and prevents excessive deformation of the main lip 7A of the seal member without using other parts, thereby preventing an increase in the number of parts and cost reduction. Can be planned.

In this embodiment, the sealing device has been described as a gas stay. However, the present invention is not limited to this, and the sealing device can be used in other devices. It can be applied when reciprocating.

(Second Embodiment) FIG. 2 shows a second embodiment. In the first embodiment, the bush 4 is provided with the annular protrusion 4A for preventing the deformation of the main lip 7A. In the present embodiment, the cover 8 is provided on the surface of the sealing member 7 on the sealed fluid side. Other configurations and operations are the same as those of the first embodiment, so that the same components are denoted by the same reference numerals and description thereof will be omitted.

The sealing device 1 of the present embodiment includes a sealing member 7 and a reinforcing ring 8 provided on a surface of the sealing member 7 on the side of the sealing fluid and having a support portion for supporting the sealing member 7. .

The reinforcing ring 8 is formed of a material such as metal or resin, and has a shape conforming to the shape of the surface of the seal member 7 on the sealed fluid side. Is baked. The support portion of the reinforcing ring 8 is baked on the surface of the main lip 7A on the sealed fluid side.

In the sealing device 1 having the above-described structure, the reinforcing ring 8 is baked on the sealing member 7, and the supporting portion of the reinforcing ring 8 fixes the main lip 7A of the sealing member 7, thereby restricting excessive deformation. Therefore, even when the piston rod 2 moves in the direction A, excessive deformation of the main lip 7A is prevented by the reinforcing ring 8, and cracking or breakage of the main lip 7A is prevented.

Therefore, similarly to the first embodiment, the durability of the main lip 7A can be improved, and the sealing performance and the durability of the sealing device 1 can be improved.

Further, the reinforcing ring 8 can prevent the deformation of the seal member 7 which degrades the sealing performance such as the heel protrusion while reinforcing the seal member 7, and can prevent the seal member 7 from deforming.
Of the high pressure gas 5 can be prevented.

[0032]

According to the present invention, the bearing is provided with an annular projection projecting in the axial direction and supporting the lip portion, so that the bearing does not require any other parts, prevents shaft eccentricity, and prevents the lip of the seal member from becoming eccentric. It is possible to prevent excessive deformation of the lip portion, and when the lip portion is going to deform excessively, the lip portion is supported against the annular projection projecting in the axial direction to prevent excessive deformation of the lip portion. As a result, it is possible to prevent the lip portion from being cracked or broken due to repeated excessive deformation, and to improve sealing performance and durability.

Since the reinforcing ring has a supporting portion for supporting the lip portion on the surface on the sealed fluid side, the reinforcing ring can prevent the lip portion from being excessively deformed while reinforcing the seal body. It is supported by the support portion on the sealing fluid side surface of the sealing member, prevents excessive deformation of the lip portion, prevents cracks and breaks in the lip portion due to repeated excessive deformation, sealability and durability Performance can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a sealing device according to a first embodiment.

FIG. 2 is a sectional view showing a sealing device according to a second embodiment.

FIG. 3 is a sectional view showing a conventional sealing device.

FIG. 4 is a cross-sectional view showing a state in which a crack or a break has occurred in a lip portion of a conventional sealing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing device 2 Piston rod 3 Tube cylinder 4 Bush 5 High pressure gas 6 Metal ring 7 Seal member 8 Reinforcement ring

Claims (2)

[Claims] 1. An annular gap between a shaft and a housing, which are assembled concentrically with each other, is reciprocally sealed. The seal is disposed on a sealing fluid side of a bearing and extends to the sealing fluid side to slide on the shaft. A sealing device provided with a sealing member having a lip portion that movably sealingly contacts, wherein the bearing has an annular projection that protrudes in an axial direction and supports the lip portion. 2. A sealing member for sealing an annular gap between two members assembled concentrically with each other so as to be relatively movable, and having a lip portion slidably sealingly contacting at least one of the two members. And a reinforcing ring that reinforces the sealing member, wherein the reinforcing ring has a support portion that supports the lip portion on a surface on a sealed fluid side.