Abstract: In a double-headed piston type compressor provided with a rotary valve in a rotary shaft, the rotary valve has an introducing port for introducing refrigerant from a suction-pressure region through a supply passage and a respective suction port into a compression chamber. A shaft seal between a front housing and the rotary shaft for preventing leakage of refrigerant along a peripheral surface of the rotary shaft is accommodated in a shaft seal chamber formed in the front housing. A communication passage connects the shaft seal chamber to the cam chamber. A communication groove is formed in an outer peripheral surface of the rotary shaft that forms the rotary valve adjacent to the front housing for communication between the introducing port and the shaft seal chamber. The supply passage and the cam chamber are in communication through the communication groove, the shaft seal chamber and the communication passage.

Abstract: In a double-headed piston type compressor provided with a rotary valve in a rotary shaft, the rotary valve has an introducing port for introducing refrigerant from a suction-pressure region through a supply passage and a respective suction port into a compression chamber. A shaft seal between a front housing and the rotary shaft for preventing leakage of refrigerant along a peripheral surface of the rotary shaft is accommodated in a shaft seal chamber formed in the front housing. A communication passage connects the shaft seal chamber to the cam chamber. A communication groove is formed in an outer peripheral surface of the rotary shaft that forms the rotary valve adjacent to the front housing for communication between the introducing port and the shaft seal chamber. The supply passage and the cam chamber are in communication through the communication groove, the shaft seal chamber and the communication passage.