A rotary heat engine is comprised of a central crankshaft, a plurality of cylinder assemblies, and a plurality of heat exchanger assemblies. The central crankshaft has first end and a second end defining an axis of rotation. The plurality of cylinder assemblies are coupled to the central crankshaft. The plurality of heat exchanger assemblies are each associated with the plurality of cylinder assemblies, respectively.

An internal combustion engine comprising an engine block comprised of a main cavity, an intake plenum, and an exhaust plenum; a crankshaft supported within the main cavity of the engine block; a rotating piston assembly contained within the main cavity of the engine block and comprised of a rotatable cylinder housing having a housing axis of rotation and comprised of a plurality of pistons contained in combustion cylinders; and a rotating valve ring contained within the engine block and surrounding the rotating piston assembly, and comprised of intake ports, ignition energy ports, and exhaust ports corresponding to each of the plurality of combustion cylinders. The rotatable cylinder housing has an axis of rotation that is parallel to and offset from the crankshaft axis of rotation.

A hot fluid expansion engine has a plurality of actuator modules arranged in a star configuration around a central shaft. Each module includes a drive piston defining a working chamber of variable volume in the first enclosure; a movable displacement piston subdividing a second enclosure into a low temperature chamber of variable volume and a high temperature chamber of variable volume with the high temperature chamber communicating with a unit of a fluid heater device and the low temperature chamber communicating with the working chamber; and a fluid circulation circuit extending between the fluid heater device and the working chamber. The drive piston and the displacement piston of each actuator module are connected to the central shaft via respective first and second eccentric transmission devices suitable for imparting reciprocating motion in translation to each of the pistons with a phase lag of 90.

An internal combustion engine comprising an engine block comprised of a main cavity, an intake plenum, and an exhaust plenum; a crankshaft supported within the main cavity of the engine block; a rotating piston assembly contained within the main cavity of the engine block and comprised of a rotatable cylinder housing having a housing axis of rotation and comprised of a plurality of pistons contained in combustion cylinders; and a rotating valve ring contained within the engine block and surrounding the rotating piston assembly, and comprised of intake ports, ignition energy ports, and exhaust ports corresponding to each of the plurality of combustion cylinders. The rotatable cylinder housing has an axis of rotation that is parallel to and offset from the crankshaft axis of rotation.