Patent attributes
An external combustion engine 10 is disclosed, wherein a container 11 sealed with a working medium adapted to flow in a liquid state includes a heating unit 13 for generating a vapor of the working medium 12 by heating part of the working medium, and a cooling unit 14 for liquefying by cooling the vapor. The volume of the working medium 12 is changed by the generation and liquefaction of the vapor, and the displacement of the liquid portion of the working medium 12 caused by the volume change of the working medium 12 is converted into and output as mechanical energy. The heating unit 13 is structured so that inner members 51a, 53a arranged on the inside and outer members 51b, 53b arranged on the outside are bonded to each other. The outer members 51b, 53b are made of a second material higher in heat resistance than the first material of the inner members 51a, 53a. Further, the thickness of the inner members 51a, 53a is not smaller than the thermal penetration depth δ of the first material.