| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a temperature compensating seal device which suppresses an increase in sliding frictional resistance while maintaining a sufficient sealing performance even if temperature is raised in use, in the seal device provided with a synthetic resin seal member having a lip on the outer peripheral portion of a movable member and sealing the lip in such a manner that the lip is made to slidably contact with the inner peripheral portion of a fixing member. <P>SOLUTION: In this seal device, the fixing portion 5 formed on the inner peripheral portion of a ring-shaped flat packing 3 is fitted to and retained in an annular groove 4 formed on the periphery of a piston 1, and the lip 6 formed on the outer peripheral portion of the flat packing is sealed in such a manner that the lip is made to slidably contact with the inner peripheral surface 7 of a cylinder 2. The flat packing is made of synthetic resin material having elastic storage performance. A difference between the inside diameter of the flat packing at service temperature and the inside diameter of the bottom surface of the annular groove larger than that of the flat packing is set to be not less than one time not more than two times with respect to the difference between the inside diameter of the flat packing at a room temperature and the inside diameter of the flat packing thermally expanded at a service temperature. <P>COPYRIGHT: (C)2011,JPO&INPIT |
