Patent ID: 7650751

Claim:
A Stirling engine comprising a piston that is made to reciprocate by a power source and a displacer that reciprocates with a predetermined phase difference relative to the piston, the Stirling engine causing a working gas to move between a compression space and an expansion space, wherein in parts of the displacer and a cylinder that receives the displacer, the parts being located on the compression space side are made of metal, and the parts being located on the expansion space side are made of a low-thermal-conductivity material having lower thermal conductivity than the metal, an external diameter of the metal part of the displacer is greater than an external diameter of the low-thermal-conductivity material part thereof, and an internal diameter of the metal part of the cylinder is smaller than an internal diameter of the low-thermal-conductivity material part thereof, and the metal part of the cylinder has an inner surface along which the metal part of the displacer reciprocates.