Abstract: A constant temperature element for heating or cooling a working gas to the temperature of a control fluid is disclosed. The element includes a plurality of hollow concentric tapered rings of conductive material having a serrate configuration in section with tips projecting into the working fluid. A plate is typically attached to and generally flush with the base of the rings except for a central elongate plenum spanning the rings and having inlet and outlet ends respectively and a barrier at the center. The temperature control fluid enters at the inlet of the plenum so that it circulates through the rings and exits through the outlet of the plenum to maintain the rings, and thereby the working fluid adjacent the rings, at the temperature of the temperature control fluid.

Abstract: A thermodynamic system for interchanging thermal energy with external sources or sinks while minimizing the dead volume presented to the pressure cycle is based upon a thermodynamic machine which cycles a working fluid bidirectionally through a regenerator means and at least one external heat exchanger for interchanging thermal energy with a heat source or sink. Between the thermodynamic machine and the heat exchanger is a switchable thermal energy storage system using at least one heat load capacitor and two different circulation loops through the storage system. By switching the working fluid paths through the thermal energy storage system, thermal energy is exchanged but the thermodynamic machine is isolated from the heat exchanger at least predetermined intervals during operation, and the dead space in the external device does not affect the pressure cycle of the machine.

Abstract: An internal thermal exchanger engine which, in one embodiment, includes an enclosed cylindrical chamber having hot and cold end portions and containing an open ended heat exchanger provided with heat conductive materials such as fine copper wire strands which function in heat exchange relationship with a gas contained within the chamber. In an alternative embodiment, the enclosed chamber is in the form of a semi-cylinder, with the heat exchanger being of a wedge shape construction and being freely rotatable between a hot side of the semi-cylinder and a cold side across the arc of the semi-cylinder.

Abstract: A piston and cylinder for a Stirling engine and the like having top and bottom meshing or nesting finned conical surfaces to provide large surface areas in close proximity to the working gas for good thermal (addition and subtraction of heat) exchange to the working gas and elimination of the usual heater and cooler dead volume. The piston fins at the hot end of the cylinder are perforated to permit the gas to pass into the piston interior and through a regenerator contained therein.

Abstract: In a hot gas engine of the type having a regenerator surrounding each cylinder top a part of the upper cylinder wall and the regenerator have been made as a unit having low heat conductivity in axial and radial directions, the unit consisting of two interconnected wall elements leaving a gap of ring shaped cross section between them, and the regenerator being brazed to the outside of the outer wall element.

Abstract: A system for providing thermal energy output at intermediate levels below about 120.degree. C. uses both a conventional heat source input and an ambient heat source input to the hot and cold ends, respectively, of a Vuilleumier cycle machine. While converting thermal energy to work in both a heat engine process and a heat pump process, an intermediate working chamber integral with both processes is arranged to provide thermal output at the desired intermediate level. By maintaining the pressure ratio within predetermined limits and observing a number of temperature relationships desirably high coefficients of performance are provided with useful levels of output in a reliable system having long operating life.

Abstract: In thermodynamic apparatus and methods utilizing constant volume cycling devices, substantial improvements in energy output can be gained by utilization of an integrated thermodynamic process placing regenerator efficiency in a higher regime. Displacer elements operating in phased relation to the thermodynamic cycle provide superheating and supercooling to extended opposite ends of the regenerator, to establish steady state conditions which increase the temperature ratio of the system. In turn, the pressure ratio of the thermodynamic cycle is increased and the specific energy output improved. This expansion of the capability of thermodynamic machines for working in moderate temperature ranges is further utilized with systems for achieving thermal gain for heating or cooling, utilizing ambient energy as a heat source as well.

Abstract: A construction of a variable volume chamber that allows cycling of a working fluid to occur substantially isothermally is disclosed. The present invention provides a fixed, rigid heat conductive element within the chamber. The heat conductive element has a surface area which is large relative to that of the chamber itself. The volume of the chamber is varied by a mechanism which meshes with the heat conductive element to minimize dead volume. As a result the heat conductive element absorbs and returns heat energy to and from the working fluid in an efficient fashion, resulting in a high degree of isothermalization of the working fluid.

Abstract: A hot gas engine has an elastic and a lost motion connection between the working piston and the displacer, resulting in a rapid shifting of the displacer between its extreme positions. The hot and cold walls between which the displacer reciprocates are substantially planar and parallel, and the displacer is in the shape of a plate. The working piston comprises a diaphragm, so that there is no loss of working gas from the motor chamber.

Abstract: A novel construction of the regenerator element of regenerative thermal machines, particularly Stirling-cycle engines, is disclosed. The new regenerator construction makes specific use of the physical anisotropy of certain materials such as pyrolytic graphite to improve regenerator heat transfer and storage performance characteristics.

Abstract: A heater head for a multi-cylinder double acting hot gas engine in which each cylinder is surrounded by an annular regenerator unit, and in which the tops of each cylinder and its surrounding regenerator are interconnected by a multiplicity of heater tubes. A manifold for the heater tubes has a centrally disposed duct connected to the top of the cylinder and surrounded by a wider duct connecting the other ends of the heater tubes with the regenerator unit.

Abstract: An improved heat exchange assembly for a thermal regenerative machine such as a Stirling cycle engine or heat pump. It includes a sandwiched structure having a center regenerator layer between first and second thermal conductor layers. The regenerator has poor longitudinal thermal conductivity. The outside thermal conductors have good longitudinal heat conduction and sufficient heat storage capacity to supply or absorb the quantity of heat which is transferred between it and the gaseous working fluid of the machine during each cycle of machine operation.

Abstract: A multi-cylinder Stirling engine comprises a stationary casing, working fluid, at least one heat source, a first heat exchanger for carrying the working fluid and for transferring heat from the heat source to the working fluid thereby raising the working fluid's temperature, and an output shaft rotatably supported by the stationary casing, which provides reaction surface members in at least one chamber where the working fluid is allowed to expand as the reaction members are allowed to move with respect to the casing. A bi-directional flow regenerator with two chambers, a second heat exchanger for further lowering the temperature of the working fluid to a predetermined temperature, and a compression device for returning the relatively cool and therefore dense working fluid back into the first heat exchanger at a lower expense of work are provided. The casing output shaft with reaction members, expansion chamber and compression device have a rotary engine configuration.

Abstract: A heat exchanger system for a Stirling engine includes a heater connected to the expansion space by a pair of parallel flow ducts, and a cooler connected to the compression space by a pair of parallel flow ducts. A circulator is arranged in one of the heater ducts and one of the cooler ducts to continuously circulate working fluid from the working space, through the heat exchanger, and back into the same working space. The expansion and compression processes are thereby made more isothermal and the heat exchangers may be made smaller, more effective and with a lower pressure drop.

Abstract: A module for a double-acting four-cylinder Stirling engine includes a heater, two upper cylinder portions, two regenerator/cooler units which each have a flexibly interconnected regenerator and a cooler, two heater tube systems and two cooler tube systems. The upper cylinder portions and the regenerators extend into the heater, and are sealed and affixed thereto. The upper cylinder portions are connectible to two lower cylinder portions affixed to an engine block. The coolers are connectible to two lower cylinder portions affixed to the block. Each of the heater tube systems extends in the heater module from a respective upper cylinder portion to one of the regenerators of the engine; and, each of the cooler tube systems extends from a regenerator, through its respective cooler and through the cooler wall for connection to one of the lower cylinder portions.

Abstract: The crankcase, monoblock assembly and engine block of a hot gas engine are fixedly interconnected by a locking pin having a cold gas connecting duct. The hot gas engine is comprised of a plurality of monoblock assemblies, each assembly including a cylinder, a heater pipe system and a regenerator-cooler housing. The locking pin passes through bores formed in the regenerator-cooler housing and a cooler unit received therein and includes a cold gas connecting duct which provides communication between the cylinder and the regenerator-cooler housing.

Abstract: A compact six-cylinder, double-acting hot gas engine having a single central combustion chamber with the cylinders arranged in two groups of three and clustered around the combustion chamber axis at equal angular intervals. The engine has two crank shafts, one per group of three cylinders, rotating in the same direction and synchronized. Each crank shaft has three cranks with adjacent cranks angularly displaced 60 degrees. Each of the cranks of one crank shaft is directed oppositely to a respective one of the cranks of the other crank shaft.

Abstract: A closed fluid working system for a Stirling engine is disclosed. The working system has a plurality of chambers subdivided by double-acting pistons operating therein; the subdivided chambers are respectively hot and cold and connected in series whereby a hot chamber is always in communication with a cold chamber of the next most adjacent cylinder. Parallel arranged gas flow paths are interposed in each communication between hot and cold chambers, and regenerator-cooler mechanisms are disposed in each of said parallel arranged paths. Control means are employed to permit flow through one or more of said parallel paths or flow of different levels through all of the paths, during different load conditions of the engine to permit the regenerator-cooling capacity to be tuned to the needs of the engine.

Abstract: A heat exchanger for use in a Stirling cycle engine includes a plurality of disc-like plates which are stacked in coaxial fashion within a cylindrical housing, and are supported thereby. The plates are all identical, and are provided with a matrix of perforations extending therethrough parallel to the axis of the heat exchanger. The plates are all parallel and spaced slightly apart, and each plate is rotated about the axis of the device approximately two percent from the adjacent plates. The cylindrical housing includes a plurality of radially extending fins which are disposed within an annular fluid jacket.

Abstract: In a double-acting multi-cylinder V-configuration Stirling cycle engine having a single burner unit, the regenerator-cooler units are clustered around a central axis of the heater head with radially extending heater pipes to keep manifold volumes small and temperatures on the heater pipes high.

Abstract: The closed fluid working system of a Stirling cycle engine is disclosed having incorporated therein an improved regenerator assembly which modifies the thermodynamic responsiveness of the working system particularly during cold-start conditions. A foraminous regenerator matrix is constructed with a predetermined matrix heat capacity to void volume ratio, and has invested therein an electrical heating element arranged in thermally conductive relationship with a desired zone of the matrix. The heating element is controlled to be energized for attaining precise heat exchange conditions within the matrix.

Abstract: A hot-gas reciprocating engine in which the tubular connection members interconnect a heater duct inside the heat pipe with the engine's expansion space and regenerator, each connection member extends transverse of the center line of the relevant unit, and is connected to the heat pipe wall with a flexible sealing member.

Abstract: A hot-gas reciprocating engine comprising at least three piston-like bodies which each separate a hot space and a cold space in the relevant cylinder. Each of the hot spaces communicates, via a regenerator, with one of the cold spaces in another cylinder. Each of the piston-like bodies cooperates, by way of a drive rod, with a plate which is mounted on a rotatable shaft in such a manner that it cannot rotate with respect to this shaft, but can be tilted about a tilting shaft extending transversely of the first-mentioned shaft. Each of the cold spaces communicates, by way of a duct incorporating a control valve, with a cold space in another cylinder. Means for operating these valves are so constructed that, when the valves are opened, these means operate the means for tilting the plate, so that the plate assumes a more inclined position with respect to the shaft. The means for tilting the plate can be operated independently of the means for operating the valves.

Abstract: A rotary positive displacement, hot gas regenerative engine having at least two cylindrical rotors, each of which is disposed within an elliptical stator. The longitudinal axis of one rotor is in registration with the longitudinal axis of the other rotor. The longitudinal axis of one stator is offset from and is in spaced parallel relationship with the longitudinal axis of the other stator. The longitudinal axes of the rotors are in spaced parallel relationship with the longitudinal axes of the stators. The rotors, which are mounted on a common shaft, are provided with a plurality of radially extending slidable vanes that form a plurality of expansion chambers and a plurality of compression chambers in each rotor-stator pair. The longitudinal axis of the rotor in each rotor-stator pair is offset from the longitudinal axis of the stator of that rotor-stator pair so that the volume of the expansion chambers is greater than the volume of the compression chambers.

Abstract: An expansion mode tidal regenerator heat engine including a housing assembly enclosing an interior region, a power extraction means and a condensable vapor disposed within the interior region. A condenser is adapted to maintain a portion of the interior region at a condenser temperature equal to or below the boiling point of the working fluid at a predetermined minimum pressure. A super-heater is adapted to maintain a portion of the interior region at a super-heater temperature above the boiling point of the working fluid at a predetermined maximum temperature. A boiler is adapted to maintain a portion of the interior region below the super-heater temperature and above or equal to the boiling point of the working fluid at a predetermined maximum pressure.

Abstract: An internal combustion Stirling V-engine is disclosed having individual heat exchangers for each cylinder disposed between two adjacent cylinders. A central preheater is disposed centrally between the cylinders in the V-space to vertically overlap the cylinder heat exchanger span.

Abstract: A hot gas engine of the Stirling type is disclosed. The engine has a heater head assembly provided with a plurality of separated regenerators connected in series in the heater tube labyrinth. The regenerators may be cascaded in size and mass to meet predetermined heat exchange design conditions. The temperature of exhaust gases exiting directly from the heater head assembly can be optimized at less than 800.degree.F, but more practically at about 1,000.degree.-1,200.degree.F.