A closed cycle regenerative heat engine has a housing (12) defining a chamber (14). A displacer (18) is housed in the chamber. A shaft (24) is connected with the displacer and extends from the chamber. A power piston (30) is housed in the chamber. The displacer (18) is secured to the housing (12) and is resiliently deformable from a rest condition in response to movement of the shaft (24) to displace the working fluid in the chamber.

A four-process cycle is disclosed for a Vuilleumier heat pump that has mechatronically-controlled displacers. Vuilleumier heat pumps that use a crank to drive the displacers have been previously developed. However, mechatronic controls provides a greater degree of freedom to control the displacers. The four-process cycle provides a higher coefficient of performance than prior cycles in the crank-driven Vuilleumier heat pump and those previously disclosed for a mechatronically-driven Vuilleumier heat pump. The four-process cycle can be drawn out to provide a low demand condition by causing both displacers to remain stationary for a period of time. The four processes in which one of the displacers is commanded to move are separated by periods of inactivity in which both displacers remain stationary.

A Stirling engine with internal regenerator and integral geometry for heat transfer and fluid flow has a displacer piston with a plurality of cavities traversing through the displacer piston and arranged in a specific cross sectional geometry. A heater head has heater fin protrusions that are arranged in the specific geometry, and a cooling bridge has cooler fin protrusions that are in the specific geometry. The displacer piston alternates between the heater head and the cooling bridge, with the cavities of the piston alternately enveloping the heater protrusions and the cooling protrusions, providing more efficient heat transfer to and from the working fluid. Each cavity in the displacer also contains a regenerator core, further improving heat transfer efficiency. The heater fin protrusions may also contain thermally conductive cores. A bellows assembly may also be used to seal the displacer piston from the heater head in order to reduce unswept volume.

The present invention relates to a low temperature, low frequency Stirling engine. Its special geometry allows for large heat exchanger surfaces and great regenerators in order to reach good Carnoization efficiency factors. Displacer and power piston may be connected with circular polymer based membrane sealings to the cylinder walls. The cold space of the Stirling Engine may cylindrically Surround the outer periphery of the working cylinder, making thermal isolation obsolete. The engine is for instance suited to operate as base power prime mover using thermal solar collectors and may be coupled with hot oil or pressurized water heat storages. In the reverse mode, the Engine works as effective Heat-Pump/Cooling Engine.

A four-process cycle is disclosed for a Vuilleumier heat pump that has mechatronically-controlled displacers. Vuilleumier heat pumps that use a crank to drive the displacers have been previously developed. However, mechatronic controls provides a greater degree of freedom to control the displacers. The four-process cycle provides a higher coefficient of performance than prior cycles in the crank-driven Vuilleumier heat pump and those previously disclosed for a mechatronically-driven Vuilleumier heat pump.

In a Stirling refrigerator, a displacer has an internal space. An expander body houses the displacer so that the displacer can be reciprocated. A temperature sensor is arranged in the internal space of the displacer. A displacer rod, having an internal space, may connect to the displacer. A wiring may provide an electrical connection to the temperature sensor, the wiring arranged through the internal space of the displacer rod to outside of the expander body.

Aircraft with an emission-free drive and method for emission-free driving of an aircraft. The aircraft includes an aircraft thruster structured and arranged to generate thrust force on the aircraft, an aircraft lift device structured and arranged to generate lift on the aircraft, and a heat engine, which is structured and arranged to convert thermal energy into kinetic energy to drive the aircraft thruster, that includes at least one flat-plate Stirling engine drivable by solar thermal radiation.

Aircraft with an emission-free drive and method for emission-free driving of an aircraft. The aircraft includes a drive device structured and arranged to generate thrust, a lift device structured and arranged to generate lift, and a heat engine structured and arranged to convert thermal energy into kinetic energy to drive the drive device. The heat engine includes at least one flat-plate Stirling engine drivable by solar thermal radiation.

A free-piston Stirling cycle engine includes a hermetically sealed pressure housing with a working section and at least one displacement section adjacent to the working section. At least one working piston, which forms part of a linear generator, is movably arranged in the interior of the working section and a regenerator is arranged in the at least one displacement section such that mechanical work can be performed by the working piston when the pressure housing is filled with a working gas and under the influence of a temperature difference between the displacement section with an elevated temperature and the remainder of the pressure housing with a lower temperature and the mechanical work can be converted into electrical energy by the linear generator.

A displacer for an engine includes a body extending along a displacer longitudinal axis from a displacer first end surface to a displacer second end surface. At least one channel extends between a first opening in the displacer first end surface and a second opening in the displacer second end surface and has sidewalls therebetween defining a channel flow path. The first opening is located at a first radial distance from the displacer longitudinal axis in a first radial direction and the second opening is located at a second radial distance from the displacer longitudinal axis in a second radial direction. At least a portion of the channel flow path has a component in an angular direction that is at an angle to both the first and second radial directions.