Patent ID: 8887621

Claim:
A reciprocating compressor comprising: a cylinder and a piston one end of which defines a coupling portion rotatably coupled to a crank shaft and the other end of which is oscillatingly reciprocated in the cylinder; a piston ring groove disposed at an outer periphery of the piston; and a piston ring mounted in the piston ring groove and sealing a space between the piston and the cylinder, wherein a ring groove other than the piston ring groove is provided at the outer periphery of the piston on a side away from the piston ring groove and closer to the crank shaft, a guide ring is mounted in the ring groove in such a manner that the guide ring cannot move radially, within the ring groove, from an initial guide ring position, to thereby suppresses radial movement of the piston when the piston is tilted with respect to the cylinder, and the initial guide ring position is a radial position at which the guide ring is installed in the ring groove between the piston and the cylinder.