JP2585626Y2 - 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 such as an oil seal used for a shaft sealing portion of various devices.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a conventional sealing device of this type. This sealing device 100
Seals an annular gap between a housing 101 as two members concentrically and relatively movable and a movable shaft 102 inserted into the housing 101, and is fitted to the housing 101. It comprises an annular fitting portion 103 and a seal lip 104 that slidably and sealingly contacts the outer periphery of the movable shaft 102.

Then, the fitting portion 103 and the seal lip 10
The bellows portion 105 is provided between the four shafts 4 so as to follow the large eccentricity of the movable shaft 102.

[0004]

However, in the case of the above-mentioned prior art, the movable shaft 10 is moved from the direction of the arrow in FIG.
2 is inserted into the seal lip 104, the bellows 1
There was a problem that 05 turned up and could not return.

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 preventing the bellows portion from being turned up.

[0006]

In order to achieve the above object, the present invention seals an annular gap between two members which are mounted concentrically and relatively movable.
A fitting portion fitted to one of the two members, a seal lip slidably sealingly contacting the other of the two members, and a seal lip provided between the seal lip and the fitting portion. In a sealing device including a bellows portion for following the eccentricity of the other member, a reinforcing portion for partially increasing bending rigidity is provided in the bellows portion.

[0007]

In the sealing device having the above structure, the bellows portion is provided with the reinforcing portion for increasing the bending rigidity, so that when the other member that the sealing lip makes sealing contact with is inserted in the axial direction, the bellows portion is inserted into the bellows portion. Since the bending rigidity is enhanced by the provided reinforcing portion, the bellows portion is not turned up.

[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, the sealing device 1 is a housing 2 as two members which are mounted concentrically and relatively movably, and a movable shaft 3 inserted into the housing 2. It seals the annular gap between them.

The sealing device 1 generally includes a metal ring 4 as a fitting portion fitted to the inner periphery of the housing 2, a seal lip 5 slidably sealingly contacting the outer peripheral surface of the movable shaft 3, and a metal ring. 4 and a bellows portion 6 provided between the seal lip 5 to follow the eccentricity of the movable shaft 3, so that the fluid on the fluid side O to be sealed does not leak to the atmosphere side A. .

At one end of the metal ring 4 is provided an outward flange portion 41 extending radially outward, and at the other end an inward flange portion 42 extending radially inward is provided. The end surface of the flange portion 41 on the fluid side O to be sealed abuts against the end surface of the housing 2, and the outer peripheral surface of the cylindrical portion 43 fits on the inner periphery of the housing 2. Further, rubber-like elastic bodies 7 are integrally baked on the atmosphere-side A end surface of the outward flange portion 4, the inner peripheral surface of the cylindrical portion 43, and both end surfaces of the inward flange portion 42.

On the other hand, the seal lip 5 is
Seal lip rubber-like elastic body 51 substantially perpendicular to
And a main lip 52 and a sub lip 53 provided at the inner end of the seal lip rubber-like elastic body 51.

The seal lip rubber-like elastic body 51 has a substantially rectangular cross section and is thick.

The main lip 52 extends from the inner end of the seal lip rubber-like elastic body 51 on the fluid side O to be sealed to the sealed fluid side O in the axial direction, and has a substantially rectangular cross section inclined inward in the radial direction. . The inner peripheral surface has a plurality of steps in the axial direction, and the leading end thereof is in slidable sealing contact with the outer peripheral surface of the movable shaft 3.

The auxiliary lip 53 extends from the inner end of the seal lip rubber-like elastic body 51 on the atmosphere side A to the atmosphere side A in the axial direction, and has a substantially rectangular cross section inclined inward in the radial direction. The tip of the sub lip 53 is slidably and sealingly contacted with the outer peripheral surface of the movable shaft 3 to prevent dust and the like from entering from the atmosphere side A.

A bellows 6 is provided for connecting the outer end of the seal lip rubber-like elastic body 51 on the atmosphere side A to the inner end of the inward flange 42 of the metal ring 4.

The bellows portion 6 is made of a rubber-like elastic material, has a substantially U-shaped cross section, and has an opening on the fluid side O to be sealed. More specifically, the movable ring at the time of mounting is substantially tilted inward from the inner end of the inward flange portion 42 of the metal ring 4 toward the atmosphere side A in the radial direction inward and substantially at the position of the outward flange portion 41 of the metal ring 4. 3 is an orthogonal part 61 which is substantially orthogonal. The seal lip 5 is connected to the inward flange 4 of the metal ring 4.
2 is substantially at the same position in the axial direction as
In order to connect the seal lip 5 to the seal lip 5, the seal lip 5 extends inclining radially inward from the inner end of the orthogonal part 61 toward the fluid O to be sealed in the axial direction, that is, toward the seal lip 5, and the air side A of the seal lip 5.
And is slightly thicker than the orthogonal portion 61 and the like.

A rib 8 serving as a reinforcing portion for increasing bending rigidity extending in the axial direction is provided partially in the circumferential direction on the outer peripheral surface of the lip bellows portion 62 connected from the seal lip 5 to the orthogonal portion 61 of the bellows portion 6. It is provided near the orthogonal portion 61. The rib 8 has a semicircular cross section as shown in FIG.

In the sealing device having the above structure, a metal ring 4 is fitted to the inner periphery of the housing 2 so that the sealing device 1 is mounted between the housing 2 and the movable shaft 3, and the movable shaft 3 is attached to the seal lip 5. Since the rib 8 is provided on the lip bellows portion 62 of the bellows portion 6 when the bellows portion 6 is inserted into the inner peripheral portion, the bending rigidity is partially increased in the axial direction of the bellows portion 6, and the bellows portion 6 is turned up. There is no. Therefore, it is possible to secure the resistance of the bellows portion 6 to be turned up against the insertion of the movable shaft 3 while maintaining the eccentricity followability.

The size, shape, position, number, and the like of the ribs 8 can be appropriately adjusted and determined according to the size of the bellows portion 6 and the required load for turning up.

In the above embodiment, the bellows portion 6 has been described as having a substantially U-shaped cross section as an example. However, the present invention is not particularly limited to this shape, and may have a substantially Z-shaped cross section. Not something.

Further, the case where the ribs 8 are used as the reinforcing portions has been described as an example. However, instead of the ribs, the bellows may be partially made of a hard material to increase the bending rigidity.

[0022]

The present invention has the above-described structure and operation. Since the bellows portion is provided with a reinforcing portion for partially increasing the bending rigidity, the other member with which the sealing lip is in sealing contact with the sealing lip is axially moved. When it is inserted into the bellows, the bending rigidity is enhanced by the reinforcing portion provided in the bellows portion, and the bellows portion is not turned up.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view of a sealing device according to an embodiment of the present invention, and FIG. 1B is a sectional view taken along line XX of FIG. 1A.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sealing device 2 Housing 3 Movable shaft 4 Metal ring 41 Outward flange part 42 Inward flange part 43 Cylindrical part 5 Seal lip 51 Seal lip rubber-like elastic body 52 Main lip 53 Secondary lip 6 Bellows part 61 Orthogonal part 62 Lip bellow part 7 Rubber-like elastic body 8 rib (reinforcing part)

Claims (1)

(57) [Scope of request for utility model registration] 1. A sealing part for sealing an annular gap between two members which are mounted concentrically and relatively movably relative to each other, wherein a fitting portion fitted to one of the two members, and the two members A sealing lip slidably and sealingly contacting the other member, and a bellows portion provided between the sealing lip and the fitting portion for following the eccentricity of the other member. The sealing device according to claim 1, wherein the bellows part is provided with a reinforcing part for partially increasing bending rigidity.