into a guide grove disposed in a radial direction of the cylinder, and a back pressure chamber (a storage portion) is constituted behind each vane. The intermediate pressure of the sealed vessel is applied to the back pressure chamber of the first rotary compression element, and the high pressure which is the pressure of a refrigerant discharge side of the second rotary compression element is applied to the back pressure chamber of the second rotary compression element. Moreover, the vane of the first rotary compression element is urged toward a roller side by a spring disposed in the back pressure chamber behind the vane and the intermediate pressure applied to the back pressure chamber. The vane of the second rotary compression element is urged toward a roller sidesince the compression work is not substantially performed in the second rotary compression element, the pressure decreases owing to a circulation resistance or the like in a process in which the refrigerant discharged from the first rotary compression element flows through the second rotary compression element on a discharge side. Therefore, the discharge side pressure of the second rotary compression element becomes lower than that of the first rotary compression element.
Moreover, in a case where an evaporation temperature of the refrigerant rises at a high outside air temperature, a suction pressure of the first rotary compression element rises. In consequence, the discharge pressure of the first rotary compression element also rises. On the other hand, the discharge pressure (the high pressure) of the second rotary compression element is