Seal device

Patent metadata

Field	Value
Publication number	US-2016348789-A1
Application number	US-201515117295-A
Country	US
Kind code	A1
Filing date	Feb 16, 2015
Priority date	Mar 7, 2014
Publication date	Dec 1, 2016
Grant date	—

Abstract

A sealing device includes an elastic annular seal portion. On an inner peripheral surface of the seal portion, a main lip is in slidable contact with an outer peripheral surface of a rotary shaft, and a vacuum space side inclined surface gradually enlarges in diameter from the main lip toward a vacuum space side. On the vacuum space side inclined surface, a first annular projection is in slidable contact with the outer peripheral surface of the rotary shaft, and a second annular projection that projects toward a radially inward side is disposed between the main lip and the first annular projection. In an initial use state of the sealing device, the second annular projection is not in slidable contact with the rotary shaft; when the main lip wears to a degree that required sealing performance cannot be maintained, the second annular projection starts slidable contact with the rotary shaft.

First claim

1 . A sealing device which partitions an annular space formed between a rotary shaft and a housing surrounding the rotary shaft, into a low-pressure space and a high-pressure space whose pressure is higher than that of the low-pressure space, in an axial direction, the sealing device comprising:
an annular seal portion formed of an elastic material and being in slidable contact with an outer peripheral surface of the rotary shaft, wherein on an inner peripheral surface of the seal portion, a main lip is formed so as to be in slidable contact with the outer peripheral surface of the rotary shaft, and an inclined surface is formed so as to extend from the main lip toward the low-pressure space side and gradually enlarge in diameter toward the low-pressure space side, on the inclined surface, a first annular projection is formed so as to be in slidable contact with the outer peripheral surface of the rotary shaft in a state where the main lip is in slidable contact with the outer peripheral surface of the rotary shaft, and a second annular projection is formed so as to be disposed between the main lip and the first annular projection and project toward a radially inward side, and the second annular projection is formed such that: when the sealing device is in an initial use state, the second annular projection is not in slidable contact with the outer peripheral surface of the rotary shaft; and when the main lip and the first annular projection wear, due to use of the sealing device, to such a degree that required sealing performance cannot be maintained, the second annular projection starts slidable contact with the outer peripheral surface of the rotary shaft.

2 . The sealing device according to claim 1 , wherein a plurality of the second annular projections are formed.

3 . The sealing device according to claim 2 , wherein the plurality of the second annular projections are formed such that, when the main lip and the first annular projection wear to such a degree that required sealing performance cannot be maintained, slidable contact is started in order from the second annular projection closer to the main lip, among the plurality of the second annular projections, in accordance with an amount of the wear.

4 . The sealing device according to claim 1 , wherein a third annular projection is further formed on the inclined surface and between the main lip and the second annular projection so as to be in slidable contact with the outer peripheral surface of the rotary shaft when the sealing device is in the initial use state.

5 . The sealing device according to claim 2 , wherein a third annular projection is further formed on the inclined surface and between the main lip and the second annular projection so as to be in slidable contact with the outer peripheral surface of the rotary shaft when the sealing device is in the initial use state.

6 . The sealing device according to claim 3 , wherein a third annular projection is further formed on the inclined surface and between the main lip and the second annular projection so as to be in slidable contact with the outer peripheral surface of the rotary shaft when the sealing device is in the initial use state.

Assignees

• Koyo Sealing Techno Co Ltd
• Nabtesco Corp

Inventors

• Ikebukuro Kazuha
• Kubota Koji
• Kurita Shuji

Classifications

• F16J15/3232 Primary

  having two or more lips · CPC title

• F16J15/008 Primary

  with provision to put out of action at least one sealing; One sealing sealing only on standstill; Emergency or servicing sealings (F16J15/164 takes precedence) · CPC title

• Y10S277/91

  O-ring seal · CPC title