A heat engine is constructed from sheet metal and the like. The heat engine has an outer container and inner container which contains a displacer and a power piston. A plurality of positioning members are provided to dimensionally stabilize the inner and outer containers. By providing positioning members that extend between the inner and the outer containers, a sandwiched construction is obtained which allows the inner and outer containers to reinforce each other thus permitting the use of thin walled containers and improving the thermal efficiency of the heat engine and decreasing the weight of the heat engine.
This application claims the benefit of U.S. Provisional Application No. 60/182,050, filed Feb. 11, 2000, U.S. Provisional Application No. 60/182,105, filed Feb. 11, 2000, and U.S. Provisional Application No. 60/182,106, filed Feb. 11, 2000.
A Stirling engine includes a heat exchanger having helical and axial fins forming an orthogonal grillage on either side of a pressure resisting wall, and an outer reinforcing sleeve about the helical fins. The sleeve improves the pressure resisting ability of a thin separating wall between a pressurized fluid and an outside working environment, resulting in a high-pressure and temperature heat exchanger with high heat transfer efficiency. In addition, the sleeve and helical fins together define fluid passages for the flow of heating fluid. The heat exchanger according to the invention has the ability to resist high pressures at high temperatures without excessive distortion, has improved heat transfer capability, better reliability, and lower production cost than prior art heat exchangers.