The present disclosure provides a sealing ring assembly having a sealing ring and a reinforcement, configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The sealing ring may be segmented, and a metal layer, wire, or other reinforcement may be affixed to the ring. The reinforcement is placed into tension against the sealing ring, which is correspondingly placed into compression. The composite structure of a relatively brittle sealing ring and reinforcement provides for reduced tensile loads in the sealing ring, thus extending life and reducing the likelihood of failure. The brittle portion of the sealing ring assembly may include a polymer or ceramic such as graphite, which is relatively less strong in tension than compression.

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

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

A Stirling cycle machine with a liquid fuel/gaseous fuel burner. The burner may include a preheater to capture the thermal energy of the exhaust. The burner directs the preheated air to each burner head, where it enters a prechamber. Each burner head includes a fuel nozzle that directs liquid or gaseous fuel into the prechamber. The prechamber is fluidically connected to a combustion chamber via a prechamber nozzle that has a smaller opening than the prechamber. The burner head ignites the fuel air mixture in the prechamber with an ignitor located above or within the prechamber. The flame is initially lit as a diffusion flame in the prechamber. The flame is pushed out of the prechamber into the combustion chamber by an increased air flow rate. The liquid fuel from the nozzle now evaporates in the prechamber and forms a prevaporized flame in the combustion chamber.

An engine body may include a piston body comprising a piston chamber and a regenerator body comprising a regenerator conduit. An engine body may include a working-fluid heat exchanger body comprising a plurality of working-fluid pathways fluidly communicating between the piston chamber and the regenerator conduit. Additionally, or alternatively, an engine body may include a heater body comprising a plurality of heating fluid pathways and the plurality of working-fluid pathways. The heating fluid pathways may have a heat transfer relationship with the working fluid pathways. The working-fluid pathways may fluidly communicate between the piston chamber and the regenerator conduit. The engine body may include a monolithic body defined at least in part by the piston body, the regenerator body, and the working-fluid heat exchanger body, and/or defined at least in part by the piston body, the regenerator body, and the heater body.

An engine body may include a piston body comprising a piston chamber and a regenerator body comprising a regenerator conduit. An engine body may include a working-fluid heat exchanger body comprising a plurality of working-fluid pathways fluidly communicating between the piston chamber and the regenerator conduit. Additionally, or alternatively, an engine body may include a heater body comprising a plurality of heating fluid pathways and the plurality of working-fluid pathways. The heating fluid pathways may have a heat transfer relationship with the working fluid pathways. The working-fluid pathways may fluidly communicate between the piston chamber and the regenerator conduit. The engine body may include a monolithic body defined at least in part by the piston body, the regenerator body, and the working-fluid heat exchanger body, and/or defined at least in part by the piston body, the regenerator body, and the heater body.

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.

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.

According to an embodiment of a hot air engine, the hot air engine includes a transmission with a connecting rod and a double-acting step piston. The double-acting step piston has a first section with a larger diameter and a second section with a smaller diameter, and is arranged in a cylinder. The double-acting step piston is at least partially hollow and the connecting rod extends through the second section and is articulatedly connected in the first section of the double-acting step piston. The double-acting step piston has sealing rings both in the first section and in the second section.

According to an embodiment of a hot air engine, the hot air engine includes a transmission with a connecting rod and a double-acting step piston. The double-acting step piston has a first section with a larger diameter and a second section with a smaller diameter, and is arranged in a cylinder. The double-acting step piston is at least partially hollow and the connecting rod extends through the second section and is articulatedly connected in the first section of the double-acting step piston. The double-acting step piston has sealing rings both in the first section and in the second section.