Patent ID: 7028475

Claim:
A fluid machine comprising: a housing; an expansion-and-compression device having a function of a compressor device for compressing working fluid in a refrigeration cycle when the expansion-and-compression device is driven in a first rotational direction and having a function of an expansion device for collecting heat energy from working fluid in a heat collecting cycle and converting the collected heat energy into mechanical rotational energy, wherein the expansion-and-compression device is rotated in a second rotational direction, which is opposite to the first rotational direction, when operated as the expansion device; an electric rotating device having a function of an electric motor for outputting the mechanical rotational energy and having a function of an electric power generator for outputting the mechanical rotational energy; a power transmission means provided in a power transmitting path between the expansion-and-compression device and the electric rotating device for transmitting the mechanical rotational energy from the expansion-and-compression device to the electric rotating device with rotational speed being changed, wherein the expansion-and-compression device, the electric rotating device and the power transmission means are integrally housed in the housing, and the expansion-and-compression device is operatively connected with an outside driving source, so that the expansion-and-compression device is operated as the compressor device by a driving force of the outside driving source.