Expansion machine

The expansion machine comprises a power source, a first expansion assembly, a second expansion assembly and a communicating piece, the first expansion assembly and the second expansion assembly are both used for expanding gas, and the first expansion assembly and the second expansion assembly are arranged at the two ends of the power source correspondingly and connected with the power source. The power source drives the first expansion assembly and the second expansion assembly to do work, one end of the communicating piece is connected with the first expansion assembly so that gas expanded by the first expansion assembly can flow into the communicating piece, and the other end of the communicating piece is communicated with the second expansion assembly so that the second expansion assembly can expand gas flowing out of the communicating piece. The expansion machine has the advantages of being simple in structure, high in expansion efficiency, long in service life and the like. 本发明公开了一种膨胀机，所述膨胀机包括动力源、第一膨胀组件、