| 摘要 |
PURPOSE:To prevent leakage of high-pressure gas into a cylinder chamber, by applying a high pressure of discharge gas to the back surface of a retainer plate disposed between a cylinder and an upper bearing or a lower bearing, and thereby urging the retainer plate onto the end face of a roller. CONSTITUTION:Discharge pressure in a case is carried into a pressurizing groove 20 from a communicating port 21 so that it is applied as a back pressure to the upper surface of a retainer plate 18. Resultantly, the retainer plate 18 located on the side of a suction chamber 14 of a cylinder 5 is urged downward by the differential pressure of the back pressure and the suction pressure. On the side of a compression chamber 13, on the other hand, the retainer plate 18 is depressed also downward by the differential pressure of the back pressure and the pressure in the compression chamber 13 since pressure in the compression chamber 13 is lower than the back pressure until it is raised to the discharge pressure. Therefore, the retainer plate 18 is deflected to a position where it is held in contact with the end face of a roller as shown by the dotted line in the drawing, so that the clearance C at the end face of the roller can be reduced. |
