Abstract: A positive displacement expander with an operating fluid chamber of expansive volume regulated by a shifting head. The shifting head may enhance rotation of a housing utilized to rotate a shaft for providing work to any of a variety of power retrieval devices. Additional efficiencies may also be realized through unique hydraulic layouts for circulating of the operating fluid from a heat exchanger, through the rotary device and to a cold exchanger for continuous operating of the rotary device.

Abstract: An assembly with a piston reciprocated with the aid of a floating head in fluid communication with the piston. The assembly may utilize a floating head that is shifted in position to promote reciprocation of the piston through the aid of pressure supplied to the floating head from a pressure volume regulator. Alternatively, the floating head may be in fluid communication with the piston at one side of the head and isolated at the other side. In this manner changing volume and pressure at this other side of the head during reciprocation may ultimately lead to floating head movement toward the piston, thereby promoting the continued reciprocation. Additional efficiencies may also be realized through unique hydraulic layouts for both operating and working fluid circulations.

Abstract: A positive displacement expander with an operating fluid chamber of expansive volume regulated by a shifting head. The shifting head may enhance rotation of a housing utilized to rotate a shaft for providing work to any of a variety of power retrieval devices. Additional efficiencies may also be realized through unique hydraulic layouts for circulating of the operating fluid from a heat exchanger, through the rotary device and to a cold exchanger for continuous operating of the rotary device.

Abstract: An assembly with a piston reciprocated with the aid of a floating head in fluid communication with the piston. The assembly may utilize a floating head that is shifted in position to promote reciprocation of the piston through the aid of pressure supplied to the floating head from a pressure volume regulator. Alternatively, the floating head may be in fluid communication with the piston at one side of the head and isolated at the other side. In this manner changing volume and pressure at this other side of the head during reciprocation may ultimately lead to floating head movement toward the piston, thereby promoting the continued reciprocation. Additional efficiencies may also be realized through unique hydraulic layouts for both operating and working fluid circulations.

Abstract: An engine utilizing multiple closed loop heat exchangers. The engine makes use of a first exchanger dedicated to a given chamber of a piston assembly. This exchanger is configured to provide both heating and cooling to the chamber for changing the volume thereof in stroking the piston. The second exchanger is configured similarly to provide both heating and cooling to another chamber at the opposite side of the piston for correspondingly facilitating a change in its volume as the piston is stroked. This unique configuration allows for the working substance in the chambers, generally an operating CO2 fluid, to effectively remain in a supercritical state for the substantial duration of the thermal cycle.