Patent ID: 7540727

Claim:
A capacity varying rotary compressor, comprising: a first cylinder and a second cylinder provided in a casing, the first and second cylinders being coupled to a rotary shaft by first and second rolling pistons; an upper bearing positioned at an upper surface of the first cylinder, a middle bearing positioned between a lower surface of the first cylinder and an upper surface of the second cylinder, and a lower bearing positioned at a lower surface of the second cylinder; a vane that divides an inner space of the second cylinder into a suction chamber and a compression chamber; a vane pressure chamber formed at a rear portion of the vane, defined by the second cylinder and the middle and lower bearings; a pressure controlling unit that supplies a discharge pressure or a suction pressure to the vane pressure chamber so as to restrict or release a motion of the vane; a connection unit that extends from a connection pipe of the pressure controlling unit, through the casing, and to the vane pressure chamber formed in the second cylinder so as to supply the discharge pressure or the suction pressure to the vane pressure chamber; and a coupling unit that couples the cylinder and the middle and lower bearings to each other so as to prevent a leakage of pressure from the vane pressure chamber, wherein the vane pressure chamber comprises a pressure space that extends from a vane slot formed in the second cylinder, and wherein the coupling unit is coupled to extension portions of each of the first middle and second lower bearings such that the extension portions hermetically seal the pressure space of the second cylinder.