Abstract: A rotary compressor has an electric motor and a compressing mechanism drivingly connected together by a crank shaft and disposed in a closed housing. The compressing mechanism has a rolling piston rotatable in a cylinder bore and driven by an eccentric portion of the crank shaft. First, second and third balancers are mounted on an end of the crank shaft and on the opposite ends of a motor rotor, respectively. The second and third balancers are formed therein with weight-adjusting holes by which the masses of the second and third balancers are finely adjusted to fall within tolerable ranges.

Abstract: A rotary compressor has a compression mechanism including main and sub bearings closing the ends of a cylinder bore and supporting a crankshaft having an eccentric portion on which a rolling piston positioned in the cylinder bore is rotatably mounted. Oil grooves are formed in the shaft holes of the bearings to receive lubrication oil from spaces defined by the rolling piston, the crankshaft eccentric portion and the main and sub bearings. The eccentric portion and the sub bearing are sized and shaped such that the oil groove in the sub bearing is always prevented from opening to the space adjacent thereto. The drawing force generated in the oil groove in the sub bearing by the rotation of a balancer attached to the lower end of the crankshaft is thereby prevented from acting on the space, thereby avoiding cavitation abrasion of the members facing the spaces.