Patent ID: 8419382

Claim:
A piston compressor, comprising: a cylinder block having a shaft hole, a plurality of cylinder bores located around the shaft hole, and a plurality of communication passages communicating with associated cylinder bores and the shaft hole; a rotary shaft inserted through the shaft hole and having an in-shaft passage formed therein; a cam rotating integrally with the rotary shaft and accommodated in a cam chamber; pistons accommodated in the respective cylinder bores to form therein compression chambers, the pistons being coupled to the rotary shaft through the cam so that rotating motion of the rotary shaft is transmitted to the pistons; a thrust bearing provided between the cam and the cylinder block, the thrust bearing including a first race in contact with the cam, a second race in contact with the cylinder block, and rolling elements retained between the first and second races to form a gap therebetween; a rotary valve formed integrally with the rotary shaft for introducing refrigerant into the compression chambers from the in-shaft passage, wherein the in-shaft passage has an outlet on the outer peripheral surface of the rotary shaft through which the in-shaft passage is communicated with the communication passages so that the refrigerant introduced into the compressor is delivered through the outlet of the in-shaft passage and the communication passages to the compression chambers; and an oil groove formed on the outer peripheral surface of the rotary shaft in its longitudinal direction, wherein the oil groove connects the gap and the outlet of the in-shaft passage which is spaced apart from the gap in the longitudinal direction.