Rotary gas compressor having rolling pistons

Abstract

A multi-cylinder single-stage rotary rolling piston type gas compressor comprises four modular cylinder housings, partitions and end covers bolted together in end-to-end arrangement. Each cylinder housing includes an inner wall which defines a centrally located cylinder chamber and vane slot and an outer wall which defines a suction chamber, a discharge chamber and an oil chamber or reservoir surrounding the cylinder chamber. The four suction chambers are connected together end-to-end to a common gas inlet port. The four discharge chambers are connected together end-to-end to a common gas discharge port. The four oil chambers are connected together end-to-end. An internally lubricated rotor assembly extends axially through the four cylinder chambers and comprises a shaft rotatably supported on the end covers. The shaft has four eccentric crankarms on which four roller pistons are rotatably mounted, one for each cylinder chamber. The two central pistons are angularly displaced 180.degree. from the two end pistons to provide balance. The rotor shaft drives an oil pump connection to the oil reservoir. Each vane slot for a cylinder chamber has at least one reciprocably movable low-mass hollow externally-grooved spring-biased gas-pressurized vane slidably mounted therein and slidably engaged with an associated roller piston. Each cylinder chamber has a gas suction port in the inner wall on one side of the vane slot communicating with the suction chamber. Each cylinder chamber has a plurality of gas discharge ports in the inner wall on the other side of the vane slot and each discharge port accommodates a spring- and gas-pressure biased, normally closed, gas-operated poppet type discharge valve which allow complete gas expulsion to the discharge chamber.