| 摘要 |
PROBLEM TO BE SOLVED: To allow to increase or decrease the sliding resistance of a sliding member such as a piston by selecting the angle between the straight line combining the first projection and the second projection, and the axial line of a packing, to the increase of the pressure of a pressure fluid, and thereby, to prevent the variation of the sliding resistance even though the pressure of the fluid is changed, and furthermore, to increase the durability, and to allow to stabilize the speed at the sliding part. SOLUTION: When a compressed air flows in to the gap between a cylinder 52 and a piston 54, a force F is applied orthogonal to the straight line to combine the first projection 68 and the second projection 70 which are formed around a packing 50, by the pressure of the compressed air. One side component force Fx of this force F deformes the above second projection 70, and it operates to increase the sliding resistance of the cylinder 52 and the packing 50, but the other side component force Fy deformes the second projection 70 to the inner side in the radius direction, to operate to reduce the sliding resistance. When the amounts of the component forces Fx and Fy are equal, the sliding resistance is made constant regardless of the pressure of the pressure field. |
