摘要 |
In a compression/expansion unit (30) serving as a fluid machine, both of a compression mechanism (50) and an expansion mechanism (60) are contained in a single casing (31). A shaft (40) coupling the compression mechanism (50) to the expansion mechanism (60) has an oil feeding channel (90) formed therein. Refrigerating machine oil accumulated at the bottom of the casing (31) is sucked up into the oil feeding channel (90) and fed to the compression mechanism (50) and the expansion mechanism (60). The refrigerating machine oil fed to the expansion mechanism (60) is discharged from the expansion mechanism (60) together with the refrigerant after expansion, flows through the refrigerant circuit and then flows back to the compression mechanism (50) in the compression/expansion unit (30). |