Patent ID: 8087260

Claim:
A fluid machine comprising: a compression mechanism for compressing a working fluid; an expansion mechanism for expanding the working fluid and for recovering mechanical power from the expanding working fluid; a shaft for coupling the compression mechanism and the expansion mechanism and for transferring the mechanical power recovered by the expansion mechanism to the compression mechanism; and a closed casing for accommodating the compression mechanism, the shaft and the expansion mechanism, and having an internal space into which the working fluid that has been compressed by the compression mechanism is discharged, wherein the expansion mechanism is a rotary expansion mechanism including: a roller mounted on the shaft; a cylinder in which the roller is disposed; and a suction pipe for guiding the working fluid to be expanded to the expansion mechanism, the cylinder is provided with a through-hole extending in an axis direction of the shaft between an expansion chamber in the cylinder and an outer circumferential surface of the cylinder, the through-hole having a larger flow passage area than that of the suction pipe, and the suction pipe, the through-hole, and a suction port opening to the expansion chamber are arranged in this order along a flow direction of the working fluid so that the working fluid that has flowed into the through-hole through the suction pipe flows from a first side to a second side of the axis direction and thereafter is drawn into the expansion chamber through the suction port.