A rod seal assembly. The rod seal assembly includes a housing between two spaces configured to receive a reciprocating rod, the reciprocating rod disposed within a first space and a second space, a floating bushing configured to move axially and radially within the housing and disposed coaxially around the reciprocating rod, a rod seal configured to seal the outside diameter of the reciprocating rod relative to an inside surface of the floating bushing, and at least one stationary bushing fixed within the housing that may form a seal with the floating bushing to the axial flow of fluid in the presence of a pressure difference between the two spaces.

A piston rod seal unit. The piston rod seal unit includes a housing, a cylinder gland, and at least one floating rod seal assembly mounted in the cylinder gland, the floating rod seal assembly comprising at least one rod seal mounted onto the floating rod seal assembly.

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.

A Stirling cycle machine. The machine includes at least one rocking drive mechanism including a rocking beam having a rocker pivot, at least one cylinder and at least one piston. The piston is housed within a respective cylinder and is capable of substantially linearly reciprocating within the respective cylinder. The drive mechanism includes at least one coupling assembly. Also, a crankcase housing the rocking beam and housing a first portion of the coupling assembly is included. The machine also includes a working space housing the at least one cylinder, the at least one piston and a second portion of the coupling assembly. An airlock is included between the workspace and the crankcase and a seal is included for sealing the workspace from the airlock and crankcase. A burner and burner control system is also included for heating the machine and controlling ignition and combustion in the burner.

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.

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.

A Stirling engine is described which, in accordance with a first exemplary embodiment, has a transmission with a connecting rod and a double-acting step piston which is arranged in a cylinder. The step piston has a first section with a greater diameter and a second section with a smaller diameter, and is at least partially hollow. The connecting rod runs on the inside through the second section, and is connected in an articulated manner in the first section of the step piston.

A system for energy conversion including a closed cycle engine containing a volume of working fluid is provided. The engine includes a double-ended piston assembly including a pair of pistons coupled to a connection member. An expansion chamber is separated from a compression chamber by the piston. The engine defines an outer end and an inner end relative to a lateral extension of the piston assembly. A heater body is positioned thermally proximal to the expansion chamber and thermally distal to the compression chamber, and the heater body is positioned at the outer end of the engine. A load device is operably coupled to the piston assembly at the inner end of the engine. The load device is positioned between the pair of pistons of the piston assembly.

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.

A beta-type Stirling machine capable of operating in a refrigeration mode. The Stirling machine has a cold section and a hot section, a displacement piston having a friction zone, and an engine piston having a friction zone. The Stirling machine has a single liner arranged in the hot section of the Stirling machine operating in the refrigeration mode, wherein the friction zones of the displacement piston and the engine piston slide within the single liner.