There is provided an internal intermediate pressure multistage compression type rotary compressor (10) capable of reducing a height dimension while reducing the amount of oil to be discharged outside. An electric element (14) and first and second rotary compression elements (32), (34) which are driven by a rotary shaft (16) of the electric element (14) disposed under the electric element (14) are provided in a hermetic shell case (12). There is provided a refrigerant introduction pipe (92) for introducing refrigerant in the hermetic shell case (12) over the electric element (14) into the second rotary compression element (34) through an outside of the hermetic shell case (12). There is provided an oil path (82) provided in the rotary shaft (16) for discharging oil through an oil discharge port (82A) which is positioned at the upper end of the rotary shaft (16). The refrigerant introduction pipe (92) is provided such that a part of an inlet (92A) of the refrigerant introduction pipe (92) is positioned under the upper end of a stator (22) of the electric element (14).

There is provided an idling engine speed control apparatus which can economically and suitably control an idling engine speed in the case where a variable displacement type compressor (1) with a variable displacement is mounted as a part of an automotive air conditioning system. At the time of idling, a duty ratio of a control valve current value sent as an external signal (S) to a control valve (16) is sent also to an engine controller, and the engine control apparatus controls the output of an engine on the basis of the duty ratio. For example, when the duty ratio becomes high from a small value, since the present operating state of the compressor (1) is in the direction where the differential pressure becomes high and the displacement is increased, it is expected that a large load is applied to the engine. Thus, in this case, the engine output is controlled correspondingly to a large duty ratio and the idling engine speed is made high.

A scroll machine has an intermediate pressure cavity which is operable to open and close a leakage path between the discharge zone and the suction zone of the scroll machine. The leakage path is closed when intermediate pressurized fluid is supplied to the cavity and the leakage path is open when the cavity is open to the suction zone of the compressor. A valve which can be mechanical or electrical is used to open and close a passageway extending between the cavity and the suction zone of the machine.