Abstract: 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.

Abstract: A Stirling engine includes a grooved cam drive mechanism with followers having a pair of longitudinally displaced bearings. One roller bearing is adapted to ride along an upper surface of the cam groove, while the other roller bearing is adapted to ride along a lower surface of the cam groove. Each follower includes an outer shaft on which a first bearing is mounted, and an inner shaft extending through the outer shaft on which a second bearing is mounted. A preferably annular space is provided between the inner and outer shafts when the follower is in an unloaded state. Then, when the follower is engaged within the grooved cam, the inner shaft is cantilevered relative to outer shaft within the annular space and results in pre-loading the first bearing against one inner surface of the groove cam and the second bearing against an opposite inner surface of the grooved cam.