| 摘要 |
PROBLEM TO BE SOLVED: To reduce a sliding loss between a driving shaft and an oscillating piston.SOLUTION: A cylindrical floating bush (48) is rotatably provided between an eccentric portion (38) of a driving shaft (36) and an oscillating piston (42). An inner peripheral surface of a cylinder chamber (50) is formed in a circular shape. An outer peripheral surface of the oscillating piston (42) is formed in a non-circular shape so that a radial distance of a gap between an envelope curve of the outer peripheral surface of the oscillating piston (42) drawn by revolving motion of the oscillating piston (42) and the inner peripheral surface of the cylinder chamber (50) falls within a predetermined allowable range over the whole circumference.SELECTED DRAWING: Figure 3 |
