A free piston Vuillermier machine which is an external combustion heat machine using a regenerative cycle, wherein a low- temperature displacer is made hollow to form a low-temperature displacer gas spring chamber, a low-temperature displacer rod is made hollow to form a hollow chamber for accommodating a high-temperature displacer rod therein as well as a high- temperature displacer gas spring chamber. Further, in the above configuration, a gas spring chamber passage may be formed to make the high-temperature displacer gas spring chamber communicate with the low- temperature displacer gas spring chamber. A high-temperature displacer mechanical spring may be provided in the high- temperature displacer gas spring chamber, and a low-temperature displacer mechanical spring mounted on the low-temperature displacer rod may be provided in the low- temperature displacer gas spring chamber.
展开▼
