Design and manufacturing of a hermetic Stirling engine

In this study, design and manufacturing of a hermetic Stirling engine having rhombic-drive mechanism were presented. In the engine, rhombic-drive mechanism was used for less vibration and piston friction. An alternator was coupled with the rhombic-drive mechanism in the engine block to convert mechanical power directly into electricity. Due to the mechanical problems, engine performance was measured without alternator unit by coupling the rhombic-drive mechanism with a dynamometer. The tests were conducted at 400 ℃ and 500 ℃ hot-end temperatures at atmospheric pressure. The surface temperature of the displacer cylinder hot end was controlled by LPG flow. The maximum torque and power obtained were 1.26 Nm at 264 r/min engine speed and 41.7 W at 350 r/min engine speed, respectively, at 500 ℃ hot-end temperature. The variation of cyclic work obtained by the experimental study was compared with the theoretical results obtained by nodal analysis.