Compressor for use in a transcritical refrigeration cycle system

摘要

A compressor (101) for use in a transcritical refrigeration cycle system, comprises a housing (4), a drive shaft (5) supported rotatably by a bearing (24) within the housing (4), a shaft seal (30, 31) interposed between the housing (4) and the drive shaft (5) so as to prevent a high-pressure fluid consisting essentially of a refrigerant and a lubricating oil from leaking from the compressor (101), and a space (40) in which are received the bearing (24) and the shaft seal (30, 31). Pressure within the space (40) is lower than the discharge pressure of the high-pressure fluid. The housing (4) is formed with a lubricating oil return passage (50) for returning lubricating oil separated from the high-pressure fluid discharged from a discharge port (3a) of the compressor (101, to the space (40).