| 摘要 |
PROBLEM TO BE SOLVED: To suppress the deformation of a lip tip under a high pressure by minutely separating the tip angle part of a rubber lip tip arranged closer to a fluid housing chamber over a seal element and slid on a rotating shaft from a rotating shaft in a non-pressurized state, and bringing it into contact with the rotating shaft in a pressurized state. SOLUTION: In the non-pressurized state of a fluid housing chamber 33, the tip angle part 14 of a lip tip 13b in a rubber lip 13 is retained in a linear contact state or minutely separated state with no fastening margin to the circumferential surface of a rotating shaft 32. In the pressurized state of the fluid housing chamber 33, a self-sealing force F1 to the circumferential surface of the rotating shaft 32 acts on the tip angle part 14 since the pressure P of a high-pressure fluid acts on the lip part 13, and the tip angle part 14 makes contact with the rotating shaft 32. On the other hand, since no straining force by the rubber elasticity of the lip 13 is generated to the circumferential surface of the rotating shaft 32, the force acting on the rotating shaft 32 of the lip tip 13b is reduced by the portion of the straining force. Accordingly, the contact surface pressure of the lip tip 13b can be reduced to reduce the wear. |
