| 摘要 |
PURPOSE:To prevent a generation of fluid leakage when a rorary shaft is stopped as well as to obtain an antiabrasive property of a lip by providing a seal member made of a rubber in a circular groove formed on the seal surface of a lip made of a synthetic resin. CONSTITUTION:When a compressor is operated, the inner circumferential surface of a seal member 10 is separated from the outer circumferential surface of rotary shaft 2 because the pressure of the sealing fluid is low and the elastic deformation amount of a thin thickness part 6a of a lip 6 is small. As a result, the seal member 10 made of a rubber whose antiabrasive property is little is never abraded by the rotation of the rotary shaft 2. On the other hand, a sufficient sealing function can be obtained by the double sealing with both side parts 9b and 9c of a circular groove 9. And when the compressor is stopped, the pressure of the sealing fluid is increased, thereby the thin thickness part 6a is deformed largely, and the inner circumferential surface of the seal member 10 in the circular groove 9 is contacted closely to the outer circumferential surface of the rotary shaft 2. But in this case, since the rotation of the rotary shaft 2 is stopped, no abrasion of the seal member 10 is generated, and even though the adhesive property of the lip 6 is not good, the adhesive property of the seal member 10 is good and a sufficient sealing function can be obtained.
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