RECIPROCATING COMPRESSOR

PROBLEM TO BE SOLVED: To provide a reciprocating compressor capable of making service life of a rider ring longer.SOLUTION: The reciprocating compressor includes a piston 32 reciprocating in a cylinder, a piston ring 74 disposed at one end on the outer peripheral side of the piston 32 in an axial direction, a rider ring loading groove 80 formed at the other end on the outer peripheral side of the piston 32 in the axial direction, and a rider ring 90 loaded in the rider ring loading groove 80. At the end of the rider ring 90 or at the end of the rider ring loading groove 80 on the other end side of the piston 32, a notched part 94 for communicating the inner peripheral side and the outer peripheral side of the rider ring 90 with each other is formed.