Patent ID: 8182251
Filing Date: 2012-05-22
Classification: F01C,F04C

Abstract:
1. An expander-compressor unit comprising: a closed casing having a bottom portion utilized as an oil reservoir, and an internal space filled with a working fluid that has been compressed and has a high pressure; a compression mechanism disposed at an upper position in the closed casing, the compression mechanism being configured to compress the working fluid and discharge the working fluid to the internal space of the closed casing; an expansion mechanism disposed at a lower position in the closed casing so that a surrounding space thereof is filled with an oil held in the oil reservoir, the expansion mechanism being configured to recover power from the working fluid expanding; a shaft coupling the compression mechanism to the expansion mechanism so that the power recovered by the expansion mechanism is transferred to the compression mechanism; an oil pump for supplying the oil held in the oil reservoir to the compression mechanism, the oil pump being disposed between the compression mechanism and the expansion mechanism in an axial direction of the shaft; and an oil supply passage formed in the shaft so that the oil discharged from the oil pump can be supplied to the compression mechanism, the oil supply passage having a lower end located below an inlet formed in an outer circumferential surface of the shaft.