Patent ID: 7524174

Claim:
A compression system comprising: a multicylinder rotary compressor in which a sealed container stores a driving element and first and second rotary compression elements driven by a rotation shaft of the driving element, the first and second rotary compression elements comprising: first and second cylinders; first and second rollers which are fitted into eccentric portions formed in the rotation shaft and which eccentrically rotate in the respective cylinders; and first and second vanes which abut on the first and second rollers to partition the inside of each cylinder into low and high-pressure chamber sides, only the first vane being urged toward the first roller by a spring member, wherein the compressor has a first operation mode in which both the rotary compression elements perform a compression work and a second operation mode in which only the first rotary compression element substantially performs the compression work, wherein in the first operation mode an intermediate pressure, which is between suction-side and discharge-side pressures of both the rotary compression elements, is applied to a back pressure of the second vane, and in the second operation mode the suction-side pressure is applied to the back pressure of the second vane, wherein in switching between the second operation mode to the first operation mode the discharge-side pressures of both the rotary compression elements are applied to the back pressure of the second vane, and thereafter the intermediate pressure is applied.