Abstract
In order to develop a low cost and small Stirling engine, a gamma-type Stirling engine which has simple moving-tube-type heat exchangers and a Rhombic mechanism has been developed. Its target shaft power is 50 W at the engine speed, 4000 rpm and the mean pressure, 0.8 MPa using helium as the working gas. In the first report [1], we measured the engine performance with atmosphere air with no-load condition and the mechanical loss with high-pressurized condition on the motoring test. Therefore, it was confirmed that the friction loss of a rotating rod seal was too strong. In this paper, we develop a hermetic generator set using the prototype engine. It is expected to decrease the mechanical loss, because the rod seal is omitted. Then, the performance is measured with high-pressurized condition using helium or nitrogen as the working gas. As the result, it is confirmed that the helium is suitable working gas for the small Stirling engine. Also, many subjects for getting more high power and efficiency are clarified.
