To enable a conventional fundamental design to be applicable approximately as it is, even when a carbon dioxide refrigerant is used as a refrigerant used in a rotary compressor.
A compression means 12 comprises a front stage compression element 20 to compress a refrigerant fed from the outside of a compressor and discharge it in a closed case 13, a rear stage compression element 30 to feed a refrigerant in the clsoed case 13 and compress the refrigerant and discharge it to the outside of the compressor, a coupling pipe 40 to guide a refrigerant in the closed case 13 to the suction port 31 of the rear stage compression element 30, and a heat insulation expander 41 to thermally expand a refrigerant in the closed case 13 and inject it in the compression chamber of the rear stage compression element 30. A part of a refrigerant discharged in the closet case 13 from the front stage compression element 20 is heat-insulated and expanded by the heat insulation expander 41 to inject it in the compression chamber of the rear stage compression element 30. The temperature and the pressure of a refrigerant under compression by the rear stage compression element 30 are prevented from exceeding respective given values.
NISHIKAWA HIROSHI
SHIMIZU EIICHI
SATO KAZUYA
HAZAMA MAKOTO
SAKAMOTO YASUO
