A monolithic heat exchanger body for inputting heat to a closed-cycle engine includes heating walls and heat sink, such as heat transfer regions. The heating walls are configured and arranged in an array of spirals or spiral arcs relative to a longitudinal axis of an inlet plenum. Adjacent portions of the heating walls respectively define corresponding heating fluid pathways fluidly communicating with the inlet plenum. At least a portion of the heat sink is disposed about at least a portion of the monolithic heat exchanger body. The heat sink includes working-fluid bodies including working-fluid pathways that have a heat transfer relationship with the heating fluid pathways. Respective ones of the heat transfer regions have a heat transfer relationship with a corresponding semiannular portion of the heating fluid pathways. Respective ones of the heat transfer regions include working-fluid pathways fluidly communicating between a heat input region and a heat extraction region.

A constant density heat exchanger and method of operating are provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first plate is positioned at the first end of the housing and rotatable about an axis of rotation such that the first plate selectively allows a working fluid to flow into the inlet of the chamber. A second plate is positioned at the second end of the housing and rotatable about the axis of rotation such that the second plate selectively allows the working fluid to flow out of the outlet of the chamber. The first plate and the second plate are rotatable about the axis of rotation so as to hold a volume of the working fluid at constant density as a heat source imparts thermal energy thereto.

Reciprocating heat engine with hot cylinder head and cold cylinder includes a cooled cylinder casing which receives a cold cylinder covered with a lubricant film and in which a piston connected to power transmission moves in translation to form a variable-volume hot chamber with a hot cylinder head which is held applied but free to expand on the cylinder casing by cylinder head applying unit, while a hot crown is interposed between the chamber and the piston and is held applied but free to expand on the piston by crown applying unit, the piston including a cooled piston sealing ring which has a piston sealing unit.

An external combustion engine including a burner element, a heater head, a piston cylinder containing a piston, a cooler and a crankcase. The crankcase includes a crankshaft, a piston rod connected to the piston, a drive mechanism for converting the linear motion of the piston rod to rotary motion of the crankshaft and a linear cross-head bearing that is connected rigidly to the piston rod at one end and to the drive mechanism at the other end. Also the external combustion engine includes a piston clearance seal and a piston rod seal unit that has floating rod seals. The piston includes a inner dome to reduce axial heat transfer via radiation and convection.

An annular venturi burner assembly and Stirling engine. The annular venturi burner injects fuel into combustion air flowing axially through a port with an annular cross section. The fuel enters the annular cross-section from the outside diameter. The flow of air through the annular section creates suction that draws the fuel through the ports. A venturi bushing directs the flow of fuel to provide improved and more uniform mixing of fuel and air.

A near adiabatic engine has four stages in a cycle: (1) a means of adiabatically expanding the working fluid during the downstroke from a high pressure/temperature level to a low level; (2) a means of cooling the working fluid at Bottom Dead Center (BDC); (3) a means of adiabatically compressing that fluid from a low pressure/temperature level at BDC to the higher level at Top Dead Center (TDC); and finally, (4) a means of passing that working fluid back to the high pressure/temperature source in a balanced pressure environment so as to minimize the resistance of that flow. This disclosure teaches the means of achieving (2) and (3) as follows: (2) a means is disclosed of BDC cooling of the expanded working fluid in the working chamber, and (3) a means is disclosed of adiabatically compressing the working fluid into the pump chamber before cycling the fluid.

A system for energy conversion, the system including a closed cycle engine containing a volume of working fluid, the engine comprising a first chamber defining an expansion chamber and a second chamber defining a compression chamber each separated by a piston attached to a connection member of a piston assembly, and wherein the engine comprises a heater body in thermal communication with the first chamber, and further wherein the engine comprises a cold side heat exchanger in thermal communication with the second chamber, and wherein a third chamber is defined within the piston, wherein the third chamber is in selective flow communication with the first chamber, the second chamber, or both.

The engine includes a first and a second cylinder chamber. The first chamber receives gas through a first inlet valve which gas will be compressed by a piston in the cylinder and will leave the first chamber through a first outlet valve. The second chamber receives compressed gas from the first chamber through a second inlet valve. The gas expands in the second chamber while performing a work on the piston before leaving the second chamber through a second outlet valve. The engine is controlled such that gas will flow from the first to the second chamber while the engine performs a working cycle and the engine is thus controlled such that a piston is used for compressing gas which performs a work on the same piston, which is connected by a rod to a cranking mechanism to transfer work from the rod by an essentially only rectilinear movement.

A thermodynamic machine designed as a two cylinder engine, working as a double acting Stirling engine. This new model of Stirling engine consists of two cylinders and three pistons of equal diameter. Pistons reciprocate in cylinders, move gas and run Stirling cycle. The gas in each cylinder is transferred to the other cylinder through pipes and the gas is displaced between hot end of engine and cold end of engine by means of these pipes. Each cylinder contains a hot end or a hot zone and a cold end or a cold zone. Thereby there are two Stirling cycles operating simultaneously but with phase offset in this engine.

The multi-temperature double-acting piston includes a peripheral sealing ring, a lower hot crown and/or an upper hot crown, and moves in translation in a cold cylinder of a heat engine which includes a lower cylinder head and an upper cylinder head, the piston including a central piston pin the lower piston rod of which passes through the lower cylinder head so as to be connected to a power transmission housed in a transmission casing, and the upper piston rod of which passes through the upper cylinder head so as to open out into a piston cooling and lubricating chamber, a lubricating-cooling gallery provided in the pin putting the chamber in communication with the casing via an internal piston volume.