Sealing device for reciprocating shaft

Abstract

A sealing device (4) for a reciprocating shaft capable of providing sufficient pressure tightness to a main lip (42) and preventing the troublesomeness of assembling operation. The sealing device interposed between the shaft (1) and the end part of an outer peripheral member (2) comprises a washer (41), the main lip (42) disposed on the sealed space (A) side of the washer (41) and slidably fitted to the outer peripheral surface (1a) of the shaft (1), an auxiliary lip (43) integrally formed on the outer peripheral side thereof, a backup ring (44) fitted between the inner peripheral part of the main lip (42) and the inner peripheral part of the washer (41) and pivotally supporting the main lip (42) from the atmosphere (B) side and the inner peripheral side, a dust lip (45) joined integrally with the atmosphere (B) side of the washer (41) and slidably fitted to the outer peripheral surface (1a) of the shaft (1), and an outer peripheral lip (46) joined integrally with the outer peripheral part of the washer (41) and fitted to the inner peripheral surface of the outer peripheral member (2).

Description

technical field [0001] The present invention relates to a sealing device for a reciprocating shaft that seals the circumference of a reciprocating shaft such as a piston rod of a hydraulic shock absorber of a vehicle. Background technique [0002] For example, Patent Document 1 and Patent Document 2 below describe typical prior art of a sealing device for a reciprocating shaft used in a hydraulic shock absorber (shock absorber) of a vehicle. Patent Document 1: Japanese Unexamined Patent Application Publication No. H10-82467 Patent Document 2: JP 2000-46092 [0003] 5 is a half cross-sectional view showing a part of a sealing device 10 for a reciprocating shaft and a hydraulic shock absorber described in the above-mentioned Patent Document 1, which is the same as the prior art, cut along a plane passing through the shaft center. That is to say, the sealing device 100 is integrally formed with the main lip 102 and the dust lip 103 that are in sliding contact with the outer...

AI Technical Summary

Problems solved by technology

In the sealing device of this structure, as a measure to effectively improve the pressure resistance of the main lip 102 that seals the working oil inside the hydraulic shock absorber, the inner diameter of the gasket 101 is effectively reduced so that it is close to the outer diameter of the rod 112 , but due to the formability of the main lip 102, there is a certain limit in reducing the inner diameter of the gasket 101

[0005] Therefore, in order to sufficiently improve the pressure resistance of the main lip 102, as described in Patent Document 2, it is very effective to support the back side and the inner peripheral side of the main lip with a backing ring made of synthetic resin. The support ring is supported between the oil seal with the main lip and the dust seal provided on the gasket outside it, therefore, the number of parts is large and the assembly work is complicated

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