Abstract: A hydraulic actuator for a multicylinder Stirling engine provided to enable modulation of the displacement of the engine. The hydraulic actuator incorporates a rotary vane configuration which provides relative rotational adjustment between components of a swashplate assembly. The relative rotation provides adjustments to the angle formed by the swashplate relative to its angle of rotation, and thus varies the stroke of each piston connecting rod, which thereby modulates the swept volume of the respective piston within its cylinder bore.

Abstract: A heater head assembly for a multi-cylinder heat engine the stirling engine, such as a multi-cylinder Stirling engine, having a plurality of regenerators and cylinders. Each regenerator has a regenerator manifold and each cylinder has a cylinder manifold. First identical cast heater tubes connect the regenerator manifold to first heater tube openings in a heater head manifold. Second identical cast heater tubes connect second heater tube openings in the heater head manifold to the cylinder manifold. The first and second heater tubes are parallel with respect to each other and form a pair of partial concentric staggered arrays. The heater tubes are rotationally asymmetric, having fin sections with less surface area upstream than downstream and thicknesses which decrease radially away from the central passageways of said heater tubes.

Abstract: A piston assembly for a double-acting engine such as a double-acting Stirling engine. A pair of sealing rings located on opposite sides of a sealing washer are positioned between a base section and a dome section of a piston head. These sealing rings are alternatively urged into sealing engagement with the cylinder bore as the piston reciprocates. A single sealing ring design is also disclosed in which the sealing ring is urged into constant sealing engagement by positive pressure accumulated with an interior cavity in the piston head.

Abstract: A crosshead system for a swashplate engine such as a Stirling cycle type. A plurality of crossheads are constrained to move in a reciprocating fashion by travelling along a pair of parallel guide rods. The crosshead system further includes a mechanism for adjusting a clearance between the crosshead elements and the opposed parallel face surfaces of the rotating swashplate. The adjustment mechanism includes a threaded adjuster cup which is maintained in a lock position through a fastener which drives a conical cone into the conical inside surface of the adjuster sleeve thus fixing its rotated and hence linear position.

Abstract: A diffuser to be used with a solar energy concentrator and a solar energy receiver to more uniformly distribute solar energy to the receiver and to reduce the amount of energy lost due to circulation of air into and out of the receiver. A portion of the solar energy passing through the energy diffusing cavities within the diffuser is reflected by the cavity walls and reoriented and diffused before being emitted to the receiver. The geometry of the energy diffusing cavities and the reflective characteristics of the cavity walls can be engineered to provide the desired degree of diffusional effect. The diffuser reduces the likelihood of inadvertent hot spots being formed, which allows the designed maximum receiver energy flux to be closer to the receiver tube material limits and allows for smaller, more compact, more efficient receivers. The diffuser also limits the circulation of air in the vicinity of the receiver tubes, which reduces energy losses and increases the overall efficiency of the system.

Abstract: A stirling engine having multiple mutually parallel distant cylinders which operates in a double acting cycle configuration. The engine includes a drive case having a rotatable drive shaft which is mounted to a cylinder block. The cylinder block includes mutually parallel cylinder bores and mutually parallel cooler bores. A generally flat retainer plate is mounted to a flat mounting surface of the cylinder bore to affix cylinder extensions and regenerator housings to the block mounting surface in alignment with the cylinder bores and regenerator bores.

Abstract: A Stirling engine having a modular construction including a drive case and a cylinder block with generally flat mounting surfaces that face each other. The cylinder block includes cylinder bores and cooler bores that are perpendicular to the cylinder block mounting surface. Piston rods extend through the plane defined by the cylinder block mounting surface and couple piston assemblies positioned within the cylinder bores to a drive shaft. Piston rod seals contain a working gas present within the cylinder block from leaking into the drive case. The same basic engine components may be used with either sliding contact rod seals or bellows or other types of hermetic sealing elements.

Abstract: A Stirling engine having multiple mutually parallel cylinders which operate in a double acting cycle configuration. The engine includes a drivecase having a rotatable driveshaft coupled to the pistons which is mounted within the cylinder block. The cylinder block includes cylinder bores and mutually parallel cooler bores. A generally flat retainer plate is fastened to a mounting surface of the cylinder block to affix cylinder extensions and regenerator housings to the block mounting surface in alignment with the cylinder bores and cooler bores.

Abstract: An electric spark type torch ignitor comprises an ignitor housing tube within which is disposed an electric ignitor. The ignitor housing tube has open forward and rear ends. The forward end is fitted to an annular shelter chamber within which the forward tip end of the electric ignitor is disposed. The electric ignitor is slid into the ignitor housing tube via the open rear end, and is located within the tube by means of several circumferentially spaced dimples that project inwardly from the wall of the tube, the electric ignitor having a shoulder that abuts these dimples. The dimples have inclined surfaces that act upon the shoulder in such a manner that the electric ignitor is centered within the tube so that an annular passageway is created around the electric ignitor within the tube. A resilient retaining spring clip acts to resiliently urge the electric ignitor forwardly within the ignitor housing tube thereby keeping the electric ignitor's shoulder against the dimples.

Abstract: A compact fuel conditioner assembly which performs fuel heating and pressure regulation functions in a circuit between a tank and a fuel injector. The assembly's body has two parallel bores arranged side by side. An electrically powered heater is disposed in one bore to heat fuel passing to the injector. The second bore is divided by a transverse wall which has a central hole. A thermal motor actuator is disposed in this second bore on one side of the transverse wall, and a spring-biased valve is disposed in the same bore on the opposite side of the transverse wall. The thermal motor actuator operates the spring-biased valve via a tubular element which passes through the hole in the transverse wall, and controls the recirculation of excess fuel returning from the injector.

Abstract: A heating system for improving the efficiency of a hot gas engine comprises a "heat pipe" type evaporator and condenser configuration forming a closed system for a condensing medium, such as sodium. The sodium is heated in the evaporator and vaporized. It flows through a conduit to the condenser where it condenses onto tubes which carry the hot working as for the engine, thereby heating the working gas. The condensed liquid sodium flows back through the conduit into the evaporator where it is again vaporized. This is a continuous cycle whereby a thermal power flow from the evaporator to the condenser is continuously induced by the heating of the sodium in the evaporator. The condenser comprises an outer cylindrical walled tube surrounding tubes which carry the hot working gas. These latter tubes are S-shaped and arranged in a bundle.