| 摘要 |
<p>PURPOSE:To reduce wear of a piston ring and a cylinder bore by forming an uneven surface in a piston ring, forming a protrusion having width lower than the reciprocating distance of a piston, and feeding lubricating oil between the piston and a cylinder. CONSTITUTION:A piston 3 is provided with a piston ring 12 to seal compressed gas between a piston 3 and a cylinder bore 2. An uneven surface is formed in the surface of the piston ring 12, and the length of at least the protrusion of the piston ring 12 is set to a value lower than the length of a minimum stroke. Further, the length of a recess is longer than that of the protrusion. This structure improves a slide condition by means of lubricating oil entering between the cylinder bore 2 and the piston ring 12 during suction of a refrigerant. This constitution reduces wear of the piston ring and the cylinder bore.</p> |
