| 摘要 |
<P>PROBLEM TO BE SOLVED: To overcome defective lubrication by efficiently separating and recovering oil mixed in refrigerant gas ejected from a scroll compressor and detecting that the evaporation temperature is below a predetermined refrigerating temperature to suck the separated and recovered oil to a scroll compression element by the pressure difference, in a cryogenic refrigerator including the scroll compressor. <P>SOLUTION: The cryogenic refrigerator is formed with a refrigerant circulation circuit wherein the refrigerant gas compressed by the scroll compressor flows into an oil separator, a condenser, a receiver tank, an expansion valve and an evaporator and then is compressed in the scroll compressor again. The fluid refrigerant of the receiver tank or part of the fluid refrigerant out of the receiver tank is supplied to the scroll compression element part, while the oil separated by the oil separator is sucked to the low-pressure part or the middle pressure part of the scroll compression element part when the evaporation temperature is reduced below a predetermined temperature, to suppress the temperature increase and the defective lubrication of the scroll compression element part. <P>COPYRIGHT: (C)2013,JPO&INPIT |
