Gas guiding mechanism in a piston type compressor

Abstract

A piston type compressor is disclosed, which includes pistons disposed in bores of a cylinder block, to be reciprocated by a piston driving mechanism in cooperation with a drive shaft. A valve receiving chamber is formed around the drive shaft in the cylinder block, for receiving a rotary valve to rotate together with the drive shaft. The rotary valve has a suction passage formed therein for providing gases from a gas suction chamber to a compression chamber defined in each bore. A plurality of communication passages are formed in the cylinder block in association with the compression chambers, to provide gas communication between the compression chambers and the valve's suction passage. A bypass passage is formed on the rotary valve, and permits one communication passage, associated with one of the compression chambers which is at a final stage of a compression stroke, to communicate with another communication passage, associated with another compression chamber which is at a start stage of the compression stroke. The compressor further includes a device, provided on an outer surface of each piston, for catching gas axially leaking along the outer surface of the piston. The gas catching device guides gas, caught by the gas catching device at the final stage of the compression stroke, to the communication passage corresponding to its associated compression chamber.