Gas guiding mechanism in a piston type compressor

Abstract

A piston type compressor is disclosed, which comprises a cylinder block having axial cylinder bores, pistons defining compression chambers in the bores, a drive shaft, and a gas suction and discharge chambers in a housing. A valve receiving chamber is formed around the drive shaft in the cylinder block, for accommodating a rotary valve which rotates in synchronism with rotation of the drive shaft. The rotary valve has a suction passage formed therein for providing gases from the gas suction chamber to a compression chamber during the chamber's gas suction stroke. A plurality of gas communication passages are formed in the cylinder block in association with the compression chambers, each having a first port open to the associated cylinder bore and a second port open to the valve receiving chamber. The first port is located at a position (P2) apart by a predetermined distance (L) from a top dead center position (P1) of the associated piston. The rotary valve has a bypass passage formed therein, for permitting one communication passage, isolated from both the compression chambers and the gas suction chamber, to communicate with another communication passage corresponding to a compression chamber in a compression stroke.