| 摘要 |
PURPOSE:To improve the sealing property of a shaft and smooth the straight movement of same by pressing hard the inner peripheral surface of a straight tubular portion elastically deformed by fluid pressure against the outer peripheral surface of the shaft. CONSTITUTION:When fluid is forced from a fluid port 19 into a fluid chamber 17 formed between a straight tube portion 11 and a sealing tool 18 to increase fluid pressure in said chamber 17 and press radially uniformly the outer peripheral surface of the straight tube portion 11. The inner peripheral surface of said portion 11 is elastically deformed and pressed hard against the outer peripheral surface of a shaft 16 to seal completely the shaft 16. When the fluid pressure in the fluid chamber 17 is regulated so that a force of the inner peripheral surface of the straight portion 11 pressing the outer peripheral surface of shaft 16 is reduced, the straight tube portion 11 is returned to the initial condition by the elastic force so that the shaft 16 carries out the straight line motion or rotational motion without being affected by the resistance of the straight tube portion 11. |
