US 4,822,059 AGranted

Dual lip seal device

AssigneeTaiho Kogyo Co., Ltd.

InventorsKeiichi Shimasaki, Hiroshi Kanayama, Hiroshi Kanemitsu, Makoto Shibata, Satoshi Asahi, Akira Takenaka

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Abstract

A lip seal device for sealing the gap between a housing and a rotary shaft comprises a case surrounding the rotary shaft, a plurality of lip seals fitted inside the case and including at least two lip seals, support means for holding the lip seals on the outer circumferential portions thereof and seal means located on the outside of the circumferential surface of the case. The inner circumferential portions of the lip seals are curved toward the sealed fluid and have a sealing surface in contact with the outside circumferential surface of the rotary shaft. The contact pressure of the lip seal furthest from the sealed fluid is lower than the contact pressure of the lip seal closest to the sealed fluid.

Claims23

Dependent claims

A lip seal device for sealing the gap between a housing and a rotary shaft, comprising:

a case surrounding said rotary shaft;
a plurality of lip seals fitted inside said case and including at least two lip seals which are a first and a second lip seals;
support means for holding said lip seals on at least the outer circumferential portions thereof;
and seal means located on the outside circumferential surface of said case, wherein said first lip seal is located nearer a sealed fluid than said second lip seal, the inner circumferential portions of said first and second lip seals being curved toward said sealed fluid and having sealing surfaces in sliding contact with the outside circumferential surface of said rotary shaft, and wherein the contact pressure of said second lip seal on said rotary shaft is set to be lower than that of said first lip seal on said rotary shaft.

1 more element

Dependencies are inferred from the claim text.