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

摘要

A multi-cylinder rotary compressor (100) is provided with a plurality of compression mechanism units (a first compression mechanism unit (10) and a second compression mechanism unit (20)). The compressor is provided with a holding mechanism which causes a vane of at least one compression mechanism unit among the plurality of compression mechanism units to have smaller pressing force for pressing the vane to the piston side than the other compression mechanism units by pull-up force acting outward in the radial direction of a drive shaft, normally performs a compression operation since pressing force generated by the gas pressure difference between inlet pressure and discharge pressure is larger than the pull-up force, and a vane leading end goes into the state of being pressed against the outer peripheral wall of a rotary piston, when the pull-up force becomes larger than the pressing force, automatically separates the vane leading end from the outer peripheral wall of the piston while maintaining a communication space for introducing oil from a closed container to a vane back surface in a discharge pressure state and maintaining the vane leading end in an inlet pressure state, and when the vane leading end is separated from the rotary piston by a given distance or more, stably holds the vane at a separated position by the difference of the pull-up force from the pressing force greatly changing in terms of a step function, and brings about an uncompressed state.