Patent ID: 7891957

Claim:
A capacity variable type rotary compressor, comprising: a casing having a gas suction pipe configured to be connected to an evaporator and a gas discharge pipe configured to be connected to a condenser; a cylinder fixed in the casing, the cylinder including an inner space at a center thereof that compresses a refrigerant as a rolling piston performs an orbit motion, an inlet penetratingly formed at the inner space and extending in a radial direction that is connected to the gas suction pipe, a vane slit that extends in a radial direction and supports a vane that divides the inner space into a compression chamber and a suction chamber by contacting the rolling piston in a radial direction, a first discharge port that discharges compressed refrigerant gas at a circumferential surface thereof, a first connection hole that is connected with the first discharge port, and a second connection hole that is connected with the inlet; a first bearing plate that covers an upper side of the cylinder first bearing plate including a bypass hole that connects the first connection hole to the second connection hole, a second discharge port that discharges the compressed refrigerant gas discharged through the first discharge port into the casing provided at a middle of the bypass hole, and a valve hole into which a sliding valve is slidably inserted; a second bearing plate that covers a lower side of the cylinder; a first discharge valve and a second discharge valve, respectively, installed at an end of the first and second discharge ports that open and close the first and second discharge ports; a capacity varying device that selectively discharges a part of the compressed refrigerant gas into the inner space of the cylinder; and a back pressure switching device that supplies a back pressure to the capacity varying device so that the capacity varying device opens and closes the bypass hole according to a driving mode of the compressor, wherein the back pressure switching device comprises: a pressure switching valve assembly connected to the gas suction pipe and the gas discharge pipe that connects the capacity varying device to the gas suction pipe and the gas discharge pipe arranged at both sides of the capacity varying device by alteration; a first connection pipe that connects a first outlet of the pressure switching valve assembly to one side of the valve hole; and a second connection pipe that connects a second outlet of the pressure switching valve assembly to another side of the valve hole.