Abstract: A Stirling engine is provided with a fluid passage that connects a low temperature-side actuating fluid space and a crankcase inner space, and a passage opening/closing valve that is provided in the fluid passage and that opens and closes the fluid passage. Upon stopping of the Stirling engine, the passage opening/closing valve enables communication through the fluid passage, at a region at which the piston floats in the cylinder. This region is determined based on the pressure of an actuating fluid in the actuating fluid space and the rotational speed of a crankshaft of the Stirling engine.

Abstract: In one embodiment according to the invention, there is provided a method for generating electrical energy using a thermal cycle of a working gas. The method comprises using the motion of a piston in a cylinder, containing the working gas performing the thermal cycle, to electromagnetically induce current in an electrical circuit coupled to the cylinder; using the electrical circuit to store the electrical energy, produced by the current induced in the electrical circuit, in an electrical storage device; and using the electrical energy stored in the electrical storage device to electromagnetically provide a motive force to the piston. Cyclically using the electrical circuit to store the electrical energy and using the stored energy to provide a motive force to the piston effect a net positive average power transfer into the electrical storage device over the course of the thermal cycle.

Abstract: In one embodiment according to the invention, there is provided a method for generating electrical energy using a thermal cycle of a working gas. The method comprises using the motion of a piston in a cylinder, containing the working gas performing the thermal cycle, to electromagnetically induce current in an electrical circuit coupled to the cylinder; using the electrical circuit to store the electrical energy, produced by the current induced in the electrical circuit, in an electrical storage device; and using the electrical energy stored in the electrical storage device to electromagnetically provide a motive force to the piston. Cyclically using the electrical circuit to store the electrical energy and using the stored energy to provide a motive force to the piston effect a net positive average power transfer into the electrical storage device over the course of the thermal cycle.

Abstract: Multiple free-piston Stirling (FPS) machines are arranged in a group and connected for preventing or minimizing vibration. A first set of identical beta FPS machines are rigidly connected together, arranged in a mechanically co-directional orientation and configured to reciprocate in thermodynamically synchronous reciprocation with each other. The first set has axes of reciprocation intersecting a first point, which may be a point at infinity. The axes of the first FPS machines make the same angle with a central axis of motion and are equi-angularly spaced around the central axis. A second set of beta FPS machines are rigidly connected together and rigidly connected to the first set of machines. The second set of machines are arranged in a mechanically co-directional orientation that is the same as the mechanical orientation of the first set of beta FPS machines.

Abstract: A method for improving performance of a free-piston engine, also comprising various other engines such as Stirling Engines, Ericsson engines, Stirling cryocoolers and other external combustion or hot air engines. The improvement is the inclusion of a means, such as a valve or set of valves interposed in a passageway, to contain the working fluid (gas) in the hot or expansion work area so that increased work can occur; or the improvement is by means of piston blocking a port to the working gas passageway such that working gas is contained in the work space such that increased work can occur. The improvement reduces or ideally eliminates free flow of fluid until such time in the cycle where valve or port opens and allows the fluid to flow to the passageway from one space to the other.

Abstract: A stirling engine is disclosed. The engine includes at least two fluid chambers; a displacer, which may be rotary; and a movable seal. At least one displacer may be included in each of the at least two fluid chambers. The movable seal separates the at least two fluid chambers. In a further aspect, a stirling engine may include any one of at least one heat source, at least one heat sink, at least one converter, or any combination of any two or more of the preceding.

Abstract: The present invention relates to a device for energy conversion, comprising: a housing provided with at least one chamber and a piston which is freely movable within said chamber, wherein said piston is capable of reciprocating movement from a central position or rest position, and wherein a gap between the piston and the wall of the chamber has a dimension that decreases as the piston moves further away from said central position or rest position.

Abstract: A high performance modular heat engine is presented that uses a highly pressurized working gas and hydraulic fluid within a pipeline or flow circuit to produce power hydraulically. It does this by adding heat to the working gas via a control loop, isolated from the power producing working gas and hydraulic fluid, to increase its pressure and impart movement to said hydraulic fluid. The heat engine can utilizes its working gas' heat of compression to improve its performance by removing it during compression and returning it to the working gas during expansion. The engine can use momentum developed internally to convert low temperature heat into high temperature heat to boost its efficiency and performance by creating an artificial high ?T between its heat source and heat sink.

Abstract: An exhaust heat recovery apparatus includes a first piston; a second piston; a first cylinder in which the first piston reciprocates; a second cylinder in which the second piston reciprocates; and a heat exchanger. The heat exchanger includes a heater that is independently shiftable with respect to at least one of the first cylinder and the second cylinder, and has one end portion arranged at a side of the first cylinder and receiving heat from heat medium, a regenerator that is arranged at a side of another end portion of the heater, and a cooler that has one end portion arranged at a side of the regenerator and another end portion arranged at a side of the second cylinder.

Abstract: An externally heated engine is provided which has a piston and a displacer. The position of the piston can be adjusted by a yoke and disk assembly on one end of a link and spacers and gaskets in the cylinder. The relative position of the displacer with respect to the piston can be changed by changing the relative position of a pair of disks in the crankshaft assembly. The displacer is caused to reciprocate by a link which is moved by a displacer cam assembly. The displacer cam assembly includes a first cam and a second cam. The first cam and the second cam each have a groove path. The displacer link follows the groove path of the cams to cause the displacer to dwell at the two ends of its stroke and to move rapidly from one end to the other.

Abstract: The concentricity and coaxiality of a central bore through a piston for a free piston Stirling machine is improved with a piston that has a sleeve with a core constructed from at least two, separate, axially-engaging core components sealed within the sleeve. During fabrication, a central bore is machined through each of the core components. The piston is assembled by heating the sleeve and cooling the core components, inserting the core components into the sleeve and then allowing the sleeve to cool and the core components to warm. This drives the core components into sealed engagement with each other and with the sleeve and aligns the central bore coaxially with the outer cylindrical surface of the sleeve.

Abstract: A linear free piston Stirling machine having an overstroke prevention mechanism for the power piston. A resilient member is fixed to the casing which contacts the power piston 4 when its displacement exceeds a predetermined level.

Abstract: A method and apparatus for converting thermal energy to mechanical energy. Operating on a thermodynamic cycle of isentropic compression, isothermal expansion, isentropic expansion and finally constant pressure cooling and contraction, an external heat engine utilizes a heat exchanger carrying heat from an external energy source to the working parts of the engine. Apparatus and methods are disclosed for engine piston timing, such that during isothermal expansion, each unit angular rotation of a drive shaft results in the capture of a constant, unit amount of working fluid expansion energy. Thus, the amount of energy captured during each unit angular rotation of apparatus drive shaft is a constant. Timing the working fluid expansion and fluid flow assures that the working fluid undergoes isothermal expansion, regardless of the quantum of heat energy applied. The modulation of heat input to the heat exchanger results in an automatic modulation of engine speed.

Abstract: To provide a less expensive and high-efficient free-piston Stirling cycle machine with an outer diameter of entire machine being relatively small. In a Stirling cycle cooler as a free-piston Stirling cycle machine including a cylinder 7, a piston 18 which is reciprocable inside said cylinder 7 and an electromagnetic driving mechanism 19 for reciprocating said piston 18, said electromagnetic driving mechanism 19 is comprised of a mover 20 and a stator 35, said piston 18 and said mover 20 formed by disposing a permanent magnets 24 outside an inner yoke 23 made of magnetic flux conducting material are disposed in an axial alignment, and said stator 35 and said cylinder 7 are disposed in an axial alignment.

Abstract: A free piston Stirling engine, comprising a power piston fitted into a cylinder further includes: a support structure carrying moving magnets for a linear alternator; and a passive structure that at normal operating power and frequency produces a restoring force on the piston in the absence of contact with the cylinder. In one variation, the passive structure further comprises a mass suspended within the piston from at least one spring, such that the mass oscillates under influence of movement of the piston at normal operating power and frequency so as to produce the restoring force. In another variation, the passive structure further comprises: a magnet disposed outside the cylinder at a position and in an orientation to produce a field that opposes a field of a moving magnet carried by the support structure when the piston moves toward the magnet.

Abstract: A linear free piston Stirling machine having a displacer piston mounted on first and second planar springs. The first spring has a stiffness which increases with increasing spring displacement. The second has a stiffness which is less variable with spring displacement to provide a combined stiffness which rapidly increases once the displacer piston displacement exceeds a fixed limit. Each of the springs has a plurality of spiral spring portions and a stress relieving hole beyond the outer edge of the spiral spring portions.

Abstract: A piston and chamber system to be used in connection with a heat concentrator such as those used for converting low grade thermal energy into useful energy. The example apparatus disclosed herein includes a heat engine floating piston which inhibits condensation normally associated with thermodynamic cycles which run at or near vapor saturation. The resulting improvement allows increased efficiency for lower temperature systems.

Abstract: Miniaturised device, which can operate as an engine or a cooler according to a Stirling thermodynamic cycle, comprising an expansion chamber and a compression chamber, which are interconnected by means of a regenerator enabling the working fluid to flow through from the expansion chamber to the compression chamber, and vice versa, under the effect of the movement of a displacing mechanism, a fraction of the compression chamber being mobile and operating as a piston in order to modify the volume of the said compression chamber, characterized in that it also comprises a complementary chamber which is connected to the compression chamber by means of a complementary connection channel, the said complementary chamber being at an intermediate temperature between the temperature of the compression chamber and the temperature of the expansion chamber, the complementary chamber being separated from the expansion chamber by means of the displacing mechanism.

Abstract: A high-temperature side power piston (37) and a low-temperature side power piston (39), respectively demarcating a high-temperature space (45) and a low-temperature space (47), brings about volumetric changes of working gases in each of the high-temperature space (45) and the low-temperature space (47). At the same time, the power pistons are configured to transmit motive energy on receipt of pressure changes of working gases. A displacer (203) movably housed in a displacer cylinder (201) transfers the working gases between the high-temperature space (45) and the low-temperature space (47) without causing a pressure difference.

Abstract: A turbomachine comprising at least one Stirling cycle thermal engine which is mounted at the end of a radial arm (36) of the exhaust casing (24) and comprises a working chamber (40) located outside the primary (B) and secondary (A) flows, a displacing piston (42) associated with a moving element (44) of an energy generation system, and two exchangers, heating (58) and cooling (62), formed in parts of the radial arm respectively intercepting the primary flow (B) and the secondary flow (A), these two exchangers (58, 62) communicating with each other and with the working chamber (40) for the circulation of a working fluid.

Abstract: A cooler machine using the Stirling cycle and comprising: at least one compressor with a compressor piston movable in a compression cyclinder; a regenerator with a regenerator piston movable in a regeneration cyclinder placed at a given angle relative to the compression cyclinder; a rotary drive crank; and two connecting rods, respectively a compressor connecting rod coupled to the compressor piston, and a regenerator connecting rod coupled to the regenerator piston, and both coupled to the crank with a mutual angular offset; the compressor and/or regenerator connecting rod is arranged to be of length that is variable over a rotation of the crank in such a manner that the movement of the corresponding piston is least slowed down on passing through top and/or bottom dead center.

Abstract: A pneumatic operating driving device, comprising at least one rotor (1) being connected to a rotatable supported shaft (3) and being brought into rotation by means of air. Near the circumference of said rotor (1), at least one cylinder (5, 15) is positioned, comprising at least one combustion chamber (8) and in which a piston (9, 20) is freely movable, which from a position near said combustion chamber (8) is moved to the other end of said cylinder by means of burning fuel in said combustion chamber, for blowing air out of a nozzle (12) towards said rotor (1). Means, such as a spring (10), are provided to bring said piston (9) back to its original position either said cylinder (15) is executed for double working. A number of cylinders (5, 15) is present divided over the circumference of the rotor (1), in which the point of time of the ignition in the combustion chambers (8) of the cylinders varies.

Abstract: A feedback control method and circuit for inclusion in a control system of an electrical power generating source that comprises a free piston Stirling engine driving a linear alternator. An instantaneous value of a variable, Vinternal, is continuously derived from other sensed and computed parameters and used in a negative feedback control loop of the control system to control engine piston stroke in order to maintain the power produced by the engine equal to the power transferred from the engine to the alternator. Vinternal is the sum of the voltage induced on the alternator winding and the voltage across the equivalent circuit lumped resistance of the alternator winding. A switching mode rectifier connects the alternator winding to an energy storage capacitor or battery. A negative feedback, alternator current control loop has an output connected to the pulse width modulator of the switching mode rectifier and has a feedback circuit comprising a current sensor for sensing instantaneous alternator current.

Abstract: The reciprocatable power piston of a free-piston Stirling machine is drivingly linked to a reciprocatable component body of an associated apparatus by at least one spring with no rigid connection linking the piston to the component body. The spring drive linkage allows the power piston and the reciprocatable component body of the associated apparatus to reciprocate at different amplitudes of oscillation. Therefore, the Stirling machine and the associated apparatus can be optimized at different amplitudes of piston and the component body oscillation thereby improving the optimization of two very different dynamic systems that are drivingly connected together.

Abstract: A power piston sealing assembly in conjunction with a Stirling engine is disclosed. The power piston sealing assembly consists of one or several sealing retainers with threads alternatively using fasteners within the power piston. Said power piston sealing assembly comprises of a power piston, displacer rod seal(s), displacer seal spring(s) and sealing retainer(s) all concentrically mounted within the power piston.

Abstract: A split displacer piston assembly (1) in conjunction with a Stirling engine is disclosed. Said assembly comprises of two main parts, displacer dome (8) and displacer base (9). Within the displacer dome there are several heat shields (10). The displacer base has a piston ring assembly (12) installed in an outer perimeter groove and fixed between the displacer base and displacer dome is a displacer guide ring (11). In order to service and or replace these parts rapidly, the displacer dome and displacer base are fastened by threaded engagement.

Abstract: A linear-free piston Stirling machine comprising a displacer and a power piston. A rod is attached at one end to the displacer, extends through the power piston and is mounted to the casing at its opposite end via a spring. A resilient stopper at the opposite end is arranged to contact the engine casing if the displacement of the displacer exceeds a predetermined limit.

Abstract: An improvement is provided to a pressurized close-cycle machine that has a cold-end pressure vessel and is of the type having a piston undergoing reciprocating linear motion within a cylinder containing a working fluid heated by conduction through a heater head by heat from an external thermal source. The improvement includes a heat exchanger for cooling the working fluid, where the heat exchanger is disposed within the cold-end pressure vessel. The heater head may be directly coupled to the cold-end pressure vessel by welding or other methods. A coolant tube is used to convey coolant through the heat exchanger.

Abstract: An apparatus for producing power from a source of liquid fuel. The apparatus includes at least one capillary flow passage, the at least one capillary flow passage having an inlet end and an outlet end, the inlet end in fluid communication with the source of liquid fuel, a heat source arranged along the at least one capillary flow passage, the heat source operable to heat the liquid fuel in the at least one capillary flow passage to a level sufficient to change at least a portion thereof from a liquid state to a vapor state and deliver a stream of substantially vaporized fuel from the outlet end of the at least one capillary flow passage, a combustion chamber for combusting the stream of substantially vaporized fuel and air, the combustion chamber in communication with the outlet end of the at least one capillary flow passage and a conversion device operable to convert heat released by combustion in the combustion chamber into mechanical or electrical power.

Abstract: A method and apparatus for converting thermal energy to mechanical energy which can use a wide range of fuels and perform with a high efficiency. Operating on a little utilized thermodynamic cycle of isentropic compression, isothermal expansion, isentropic expansion and finally constant pressure cooling and contraction. The external heat engine utilizes a heat exchanger carrying heat from the external energy source to the working parts of the engine. Pistons and cylinders are activated by appropriate means to adiabatically compress the working fluid, for example ambient air, to transfer the entire mass of the air through the heat exchanger to accomplish isothermal expansion followed by adiabatic expansion and, finally, exhaust the air to ambient to allow for constant pressure cooling and contraction. Valve pistons in conjunction with the cylinders form valves that allow for the exchange of working fluid with ambient.

Abstract: An external combustion engine is disclosed, comprising a container (11) for sealing a working liquid (12) in a way adapted to allow the liquid to flow therein, a heater (13) for heating and vaporizing the working liquid (12) in the container (11), and a cooler (14) for cooling and liquefying the vapor of the working liquid (12) heated and vaporized by the heater (13). The displacement of the working liquid (12) caused by the volume change of the vapor of the working liquid (12) is output by being converted into mechanical energy. In the heated portion (11d) of the container (11) for vaporizing the working liquid (12), the direction of displacement of the working liquid (12) at the parts (17, 19) far from the cooler (14) is changed with respect to the direction of displacement at the part (16) near to the cooler (14).

Abstract: An exhaust heat recovery apparatus includes: an exhaust heat recovery unit that produces motive power by recovering thermal energy from exhaust heat, wherein the produced motive power is combined with motive power produced by a heat engine and is output together therewith; an auxiliary that is driven by at least the exhaust heat recovery unit; and a power transmission-switching device that is provided between the heat engine and the exhaust heat recovery unit, the same power transmission-switching device being provided between the heat engine and the auxiliary, and that cuts off the connection between the heat engine and the exhaust heat recovery unit when there is no request to drive the heat engine. Thus, it becomes possible to effectively use the surplus motive power produced by the exhaust heat recovery unit when there is no request to drive the heat engine.

Abstract: A cooling/heating apparatus for circulating the cooled or heated transfer medium to a load to thereby cool or heat the load includes a heat transfer medium circulation path and a Stirling heat engine. The Stirling heat engine includes a first and a second cylinder chamber; a first and a second piston for expanding or compressing an operation gas in the first and the second cylinder chamber; and a driving mechanism for driving the first and the second piston. When the driving mechanism is driven in a forward direction, the operation gas is expanded in the first cylinder chamber and its temperature decreases, thus cooling the heat transfer medium, whereas, when the driving mechanism is driven in a backward direction, the operation gas is compressed in the first cylinder chamber and its temperature increases, thus heating the heat transfer medium.

Abstract: Provided is an exhaust heat recovery apparatus that includes: an exhaust heat recovery unit that recovers thermal energy from exhaust gas discharged from a heat engine; and a power transmission-switching device that cuts off the connection between an output shaft of the heat engine and an output shaft of the exhaust heat recovery unit when the heat engine is started. With the exhaust heat recovery apparatus, the reduction in the power output from the heat engine, from which exhaust heat is recovered, is suppressed when the exhaust heat of the heat engine is recovered.

Abstract: Through stroke control whereby the stroke of a piston is detected and controlled to be equal to a target stroke, the piston is prevented from colliding with a displacer, and the refrigerating performance of a Stirling refrigerator is enhanced. Different target strokes corresponding to different operation conditions of the Stirling refrigerator are stored in a storage portion in a control box, so that a linear motor can be driven with a target stroke that suits the current operation condition. Thus, the piston is prevented from colliding with a displacer, and the refrigerating performance of a Stirling refrigerator is further enhanced.

Abstract: A control system for a Stirling engine including the use of a synchronous power converter (“SPC”) which is connected to the terminals of the alternator in a linear alternator/FPSE power system. According to the teachings of the present invention, the attached SPC is small and portable and further ensures that piston and displacer excursion within the system remain within design limits. The system and method are designed such that it is possible to adjust both the voltage amplitude and the waveform frequency at the terminals of the linear alternator. By controlling these operational aspects, both the speed and the range of travel associated with the piston and the displacer in the FPSE can be controlled.

Abstract: A heat engine has a region within which a working fluid travels and an hydraulic fluid provided in a reservoir and the output from the heat engine drives the movement of the hydraulic fluid.

Abstract: A Stirling engine, wherein when a linear motor reciprocatingly move a piston in a cylinder, a displacer also reciprocatingly moves in the cylinder storing the displacer. By this, working mixture moves between a compression space and an expansion space. Though a spring for generating resonance is combined with the displacer, a spring for generating resonance for the piston is eliminated. Gas bearings are installed for the piston at two or more positions at specified intervals in the axial direction. An inside flange formed at the end of the cylinder and a stopper plate fixed to the linear motor determine the moving limit of the piston. Since a pin projected from the stopper plate is received by a through hole in a magnet holder, the piston can be prevented from being rotated.

Abstract: A device and method for controlling the flow of a gaseous fuel from a fuel supply to a pressurized combustion chamber. A fuel pump is included in the gas train from supply to chamber. The fuel pump increases the pressure of the gas to allow efficient injection into the chamber. The pump is modulated to control the fuel flow. Both alternating current and pulse-width-modulated direct current signals may be used to control the flow. The pump may be a piston pump or a diaphragm pump. Feedback may be provided from sensors that determine operating parameters of the engine and such sensor signals may be used by the controller to maintain a parameter, such as temperature, at a specified value. An acoustic filter can be included in the gas train to significantly reduce gas flow pulsations generated by the pump. This filter improves the uniformity of the combustion process.

Abstract: In the pressure oscillation generator 1, self-excited vibration is generated in a work transfer tube 30 by heating a heat input section 22 and also a resonator 50 is resonated, and when a work is inputted into a heat exchanger 20, the work is amplified by the heat exchanger 20, and is transferred to the heat transfer tube 30 and is then outputted to an output section 40. Because of the configuration, an outputted work can be amplified to a work larger than the inputted work, so that, by using a portion of the outputted work as energy for driving the cylinder 10, the pressure oscillation generator 1 can continuously be driven only by heating and without using electric energy generated by a large scale solar system or the like, which enables substantial size reduction of the pressure oscillation generator 1.

Abstract: The intended purpose of my invention is to create a point of origin in system from which driving thrusts could evolve. In this system, vacuum can be developed with less force than it naturally is required to create said vacuum. By posting a cylinder, containing two pistons in each cylinder, on each side of the axis of rotation and having gas flow in an out the cylinders under controlled pressures, the system could create such vacuum. As a result, said vacuum can lift more mass than the mass creating said vacuum and, thus, imbalance could be achieved that rolls the system in one direction.

Abstract: An improved electrical generation system utilizing environmentally hazardous waste oils as a combustible fuel. More particularly, a system to generate electrical power using a Stirling-cycle engine driving an electrical generator. The Stirling-cycle engine is powered by the heat energy produced by a waste-oil-fired furnace. The system is of a co-generation type, producing electricity and a combination of space heating and hot water.

Abstract: A multi-stage thermoacoustic device includes a resonance tube mounted therein a plurality of stacks and a plurality of heat exchangers interlaid with each other adjacent to a second end of the resonance tube. A working fluid is filled in the resonance tube. A driver mounted on a first end of the resonance tube drives the working fluid oscillate in the resonance tube, the working fluid is compressed and expanded and causes temperature oscillation and thermal energy flowing from one end of the stack to the other end. The thermal energy, such as cooling capacity, is finally transferred outward through the heat exchangers on sides of the stacks. The multiple stacks and heat exchangers perform a multiple stage temperature gradient. More thermal energy is transferred, and the working efficiency is improved.

Abstract: A coaxial Beta type Stirling cycle device, having a power piston and a displacer coaxially positioned in series within an enclosing cylinder. The power piston and power piston shaft have an opening wherein the displacer shaft passes through. A compression chamber is formed between the pistons. An expansion chamber is formed between the displacement piston and one end of the cylinder. There is a gas path provided, so that a working gas within the cylinder can pass back and forth between the expansion chamber and the compression chamber as the pistons reciprocate. The power piston and the displacer each has its own linkage to a common cam body, which has a cam groove for the power piston and a cam groove for the displacer. The cam body is a face cam having multiple cam grooves, or a barrel cam having multiple cam grooves. The cam grooves may be shaped to provide infinitely settable stroke, dwell, and phase angle.

Abstract: A displacer spring and displacer/spring assembly for use in an FPSE and with improved wear characteristics. One embodiment calls for the use of a single machined spring operating alternately in a tension mode and a compression mode and wherein the operating frequency of displacer movement can be controlled therewith to a desired resonant frequency. The machined spring of the present invention provides enhanced structural accuracy which, in turn, leads to the elimination of lateral and side loads as compared to prior art wire-wound helical springs.

Abstract: Heat differential power systems and apparatus for powering liquid cooling systems and/or generating electrical power in a data processing system or a telecommunication system are presented. A number of embodiments are presented. In each embodiment a heat differential power system is implemented which utilizes the heat created a heat-generating component such as a microprocessor within the data processing or telecommunications system and the resulting heat differential created with other parts of the system as power to operate the heat differential power system and convert thermal energy into mechanical and/or electrical energy for powering a liquid cooling system, fans, other electrical components, and/or extending the battery life in a portable data processing or telecommunications system.

Abstract: A Stirling engine which utilizes an inner and outer dual shell pressure containment system surrounding the high pressure and temperature engine components. The space between the shells is filled with a pressure backup gas and an insulation material with the backup gas being in communications with the working fluid. The backup gas and insulation provide a time varying pressure field, driven by the pressure variations in the Stirling engine working fluid, which cancels the pressure differential on the heat transfer tubing and allows an averaging of pressures during each cycle of engine operation. In one embodiment the backup gas is placed inside the inner shell.

Abstract: A Stirling cycle machine heat exchanger and a method for making the heat exchanger including, forming an annular ring of a solid heat conductive mass, the annular ring having a central axis and having axially opposite faces. A plurality of passages are drilled through the annular ring and through the opposite faces to provide passages for the flow of a fluid through the passages and transfer of heat energy between the mass and the fluid. The passages are preferably parallel to the axis and have a circular cross section and are arranged in a plurality of circumferentially spaced sets of passages, each set having a plurality of radially spaced passages.

Abstract: A pressure vessel for containing a mechanical device operable to convert heat to mechanical or electrical power, comprising: a high temperature section, the high temperature section having a first end and an open second end, a sealing flange, the sealing flange having a first end and a second threaded end, the first end bonded to the open second end of the high temperature section, and a low temperature section having an open threaded first end, the open first end in sealing engagement with the second threaded end of the sealing flange. Also provided are a Stirling engine and a method of hermetically sealing a pressure vessel of a Stirling engine.

Abstract: A Stirling engine comprises a first porous body having a large hole diameter, a second porous body having a small hole diameter and a ring for fixing the first porous body and the second porous body in a pressurization chamber inside a gas outlet closer to the pressurization chamber.