Patent ID: 8231368

Claim:
A multi-stage rotary compressor, comprising: a casing having a sealed space therein; a driving unit installed in the casing, for generating a driving force; a first compression unit and a second compression unit for receiving the driving force from the driving unit and compressing a refrigerant; and a connection unit for selectively connecting the first compression unit to the second compression unit, wherein the connection unit comprises: a first suction pipe for guiding the refrigerant to the first compression unit; a second suction pipe for guiding the refrigerant to the second compression unit; a chamber for covering an outlet of the second compression unit to store the refrigerant discharged from the second compression unit; a first connection pipe connected to an outlet of the chamber; a second connection pipe connected between the first connection pipe and the first suction pipe; a third connection pipe connected between the first connection pipe and an inner space of the casing; a first control valve mounted on the first suction pipe, for controlling the sucked refrigerant sucked into the first compression unit; and a second control valve mounted on a joint point of the first connection pipe, the second connection pipe, and the third connection pipe, for adjusting a flow direction of the refrigerant by guiding the refrigerant discharged from the chamber to be sucked into the first compression unit or to be discharged into the inner space of the casing.