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.

Method and system for efficient energy recovery from heat source with external combustion engine. Invention include sequentially operating drive mechanism for power pistons and displacement pistons of gamma type Stirling engine, providing nearly ideal pistons operation sequence. Stirling engine is supplemented with working flow fluid control and separation member between working fluid reheater and rest of the engine during high pressure stage. Working fluid is circulated in flow control via one or more consecutive displacement cylinder/power cylinder stages before reheating. Control system is directing working fluid from inlet port to the first displacement cylinder, further to the first power cylinder and after expansion either to reheating or to the next displacement cylinder. Low temperature working fluid is finally directed back to the counter flow type reheater.

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

A constant density heat exchanger and method of operating are provided. The constant density heat exchanger includes a housing extending between a first end and a second end and defining a chamber having an inlet and an outlet. A first plate is positioned at the first end of the housing and rotatable about an axis of rotation such that the first plate selectively allows a working fluid to flow into the inlet of the chamber. A second plate is positioned at the second end of the housing and rotatable about the axis of rotation such that the second plate selectively allows the working fluid to flow out of the outlet of the chamber. The first plate and the second plate are rotatable about the axis of rotation so as to hold a volume of the working fluid at constant density as a heat source imparts thermal energy thereto.

A Stirling engine comprising a first cylinder comprising a piston configured to separate at least two expansion or compression chambers of the first cylinder, and a second cylinder comprising a piston configured to separate at least two expansion or compression chambers of the second cylinder. The pistons of the first and second cylinders are connected, such that the first and second cylinders form a first piston assembly. Each chamber of the first cylinder is fluidly connected to a chamber of a first cylinder of a second piston assembly such that a working fluid to be compressed/expanded can flow between the fluidly connected chambers of the first and second piston assemblies. Each chamber of the second cylinder is fluidly connected to a chamber of a second cylinder of a third piston assembly such that a working fluid to be compressed/expanded can flow between the fluidly connected chambers of the first and third piston assemblies. The first cylinder and the second cylinder of the first piston assembly are each configured as an expansion cylinder or a compression cylinder.

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.

An annular venturi burner assembly and Stirling engine. The annular venturi burner injects fuel into combustion air flowing axially through a port with an annular cross section. The fuel enters the annular cross-section from the outside diameter. The flow of air through the annular section creates suction that draws the fuel through the ports. A venturi bushing directs the flow of fuel to provide improved and more uniform mixing of fuel and air.