Abstract: A refrigeration gas compressor comprises a piston reciprocably movable to effect gas compression, a motor-driven rotatable crankshaft, and a connecting rod between a crank pin on the crankshaft, and a wrist pin on the piston. A crank pin receiving hole and a wrist pin receiving hole in opposite ends of the connecting rod are connected by an oil passage. The oil passage is connected to a groove in the upper side wall in the crank pin receiving hole. The crank pin has two lubricating oil supply ports at opposite sides of its outer surface through which lubricating oil is pumped. A bearing assembly comprising semi-circular upper and lower bearing sections is disposed around the crank pin. Each bearing section has a smooth inner surface. The upper bearing section has oil well recesses near, but spaced from, opposite ends of its inner surface which receive oil from the oil supply ports each time a port moves therepast.

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.