MULTI-CYLINDER ROTARY COMPRESSOR AND VAPOR COMPRESSION REFRIGERATION CYCLE DEVICE PROVIDED WITH MULTI-CYLINDER ROTARY COMPRESSOR

摘要

A multi-cylinder rotary compressor (100) includes a plurality of compression mechanism parts (a first compression mechanism part (10) and a second compression mechanism part (20)). A drawing force is applied to a vane of at least one of the compression mechanism parts radially outward with respect to a drive shaft so that a pressing force of pressing the vane toward a piston is smaller than those in the other compression mechanism parts. In a normal state, a pressing force due to a gas pressure difference between a suction pressure and a discharge pressure is larger than the drawing force, and a front end of the vane is pressed against a rotary piston peripheral wall so that a compression operation is performed. On the other hand, when the drawing force becomes greater than the pressing force, the front end of the vane is automatically moves to be separated from the rotary piston peripheral wall with a communication space through which oil is introduced from a sealed container to a rear space of the vane being in a discharge pressure state and the front end of the vane being in a suction pressure state. Then, when the front end of the vane is separated from the rotary piston to a predetermined distance or more, a significant step function change of the difference between the drawing force and the pressing force occurs, a retention mechanism stably retains the vane at a location separated from the piston, and the compression mechanism part switches to an uncompressed state.