PURPOSE: To improve the efficiency of an actuator or the like by conducting furnishing in which elastic rings whose widths in a direction where two spaces are lined are shorter than a circumferential groove, are made to weld with pressure in the same direction with that of elastic force a surface opposing a seal ring slide side.
CONSTITUTION: A pair of piston rings 21 are butted against the circumferential wall surface 3a of the circumferential groove 3 of a shaft 2 by means of pressure A during a compression process on a compression chamber C side, and fluid flows into clearances 6b, 6c and pressure E is produced, and piston rings 21 are diametrically expanded through a tension ring 51 and an elastic ring 32 retained at a groove portion 5 by means of a fixed ring 41, and leak from pressure welded surfaces (h) is reduced. Next, when the shaft 2 moves in the reverse direction, pressure A at the compression chamber C lowers more than pressure B at the opposite side space, and pressure B acts on a space between piston rings 21 and the circumferential wall surface 3a, and an elastic ring 31 and the tension ring 51 are diametrically contracted, and clearances are produced at butting surfaces (h) and also at slide contact surfaces (g) between piston rings 21 and a cylinder 1. Thus, the improvement of actuator efficiency and the reduction of drive motive power become possible.
| JPH06185619 | PISTON SEALING STRUCTURE |
| JPH06281004 | PRESSURE RING |
TODA FUJIO
MATSUO MASAHIRO
TODA FUJIO
MATSUO MASAHIRO
| JPS5056808U | 1975-05-28 | |||
| JPS6315650U | 1988-02-02 |