In this paper, a parametric study of the rhombic drive mechanism of a solar low-temperature Stirling engine was
conducted. The goal is to find out the relationship between the rhombic drive mechanism parameters and the
performance of a low-temperature differential Stirling engine. The results indicate that the offset distance from the
gear center and gear radius of the rhombic drive mechanism have to be maximized, in order to increase the
indicated power, while other rhombic drive parameters should be reduced for the same reason. Another result is that
for realizing the optimized phase angle for beta-type Stirling engines, one should act on working piston-related bars
and rhombic drive gear radius.