Abstract: An improved tangential linear flexure bearing for reciprocating machines is disclosed having improved reliability for long life, the flexure bearing being an integrated device comprising a translating cut diaphragm with circumferential tangent cantilever flexure blades secured between rim and hub spacers, the improvement being within the flexure blades having symmetrical opposing end angles and ends equally displaced from radial lines extending from the center of the diaphragm, and having grain orientation extending along the length of the flexure blades both features providing improved radial stiffness, low axial stiffness, reduced flexure stresses and increased fatigue strength for improve reliability.

Abstract: A cryogenic cooler of the pulse tube type is provided wherein the reservoir is disposed within the compressor housing. The invention provides the high efficiencies associated with orifice pulse tube cryogenic coolers, but is more compact and is generally lighter in weight than conventional pulse tube cryogenic coolers.

Abstract: In a Vuilleumier heat pump, hot and cold displacers are supported by coil springs in respective buffer chambers. Further, there are respectively provided forced vibration systems of the hot and cold displacers using, as exciting force, force applied to respective displacer rods due to a difference between a pressure fluctuation of a working gas in an inner working space and a pressure in the buffer chambers. A linear motor is also provided to drive the hot displacer so as to reciprocate. It is thereby possible to provide the Vuilleumier heat pump in which a mechanism for driving the hot and cold displacers can have a small-sized and simplified structure, and no restriction is imposed on an arrangement of hot and cold cylinders.

Abstract: A high pressure valve and low pressure valve are positioned at a hot end of the pulse tube and two direction valves are positioned respectively between the high pressure reservoir, the low pressure reservoir and the pulse tube. In the pulse tube refrigerator wherein the cold is produced by time-phase displacement with orifice, an irreversible loss is caused when the gas passes through the orifice. However, the refrigeration in this invention comprising high and low pressure reservoirs, and open and close valves, all the energy can be converted without loss in adiabatic expansion of the gas in the pulse tube, theoretical efficiency is 100%.

Abstract: A refrigerator with a regenerator having a good and stable cooling function comprises: a cylinder having a circular inner surface and being made of a material having a low heat conductivity and a high hermetic sealing performance; a displacer having a circular outer surface having a slightly smaller diameter than the inner surface of the cylinder, forming a main gas passage there through, and containing regeneration material therein, the displacer being disposed in the cylinder to be reciprocally movable in the axial direction the cylinder and forming an expansion space at one end of the cylinder; a groove pattern formed on one of the outer surface of the displacer and the inner surface of the cylinder, for forming an auxiliary gas passage for supplying gas into and recovering the gas from the expansion space, the groove pattern including a groove at least partially formed along the direction intersecting the axial direction of the displacer, such as a helical groove, the groove allowing a gas flowing through

Abstract: A split-Stirling cryorefrigerator including a cylinder containing a movable displacer containing regenerator material and having an attached movable rod with a free end located in a housing enclosing a gas-spring chamber containing a gas. The cylinder has an orifice near its warm end which is in fluid communication with a gas source having a cyclic (typically sinusoidal) pressure. The movable rod slidably and generally sealably engages the housing and the warm end of the cylinder. The cryorefrigerator also includes a mechanism for adjusting the void volume of the gas-spring chamber, such adjustment allowing for increased cooling capacity of the cryorefrigerator when the amplitude of the cyclic pressure of the gas source is increased.

Abstract: Disclosed is a low-temperature regenerative type refrigerator installed in a low temperature environment, in which a cooling water flow rate controller for adjusting the flow rate of cooling water automatically in accordance with the temperature of gas fed to an expansion unit from a compressor, is provided in a water cooling type cooler for cooling the compressor, to keep the temperature of the gas discharged from the compressor high to the extent of not deteriorating the function of a seal due to shrinkage or not causing convection or deflecting flow in a regenerator, whereby it is made possible to prevent the deterioration in the cooling efficiency of the regenerator which is caused by a lowering of the ambient temperature in the refrigerator installed place, and hence possible to prevent the deterioration of the refrigerating capacity as the entire refrigerator.

Abstract: An apparatus for compressing/expanding a working gas (compression/expansion apparatus), including: a cylinder; a piston for compressing/expanding said working gas in a working space (front space) of said cylinder; a crank mechanism connected with a piston rod of said piston via an oil seal; a crank chamber for housing therein said crank mechanism and communicating with said cylinder via said oil seal, said apparatus comprising: a first tube allowing for a unidirectional flow of the working gas from said crank chamber to said front space in said cylinder, said first tube having therein an oil filter and a first check valve; and a second tube allowing for a unidirectional flow of the working gas from said front space to a second space (rear space) behind said piston in said cylinder, said second tube having therein a second check valve.

Abstract: A piston centering system for a free piston machine. The invention uses a centering passageway which is in communication between a work space and a second space which spaces are formed in a housing and are separated by a piston which reciprocates in a cylinder in the housing. The centering passageway has a valve, such as a spool valve formed in the piston and cylinder or a center post, the valve opening in response to the piston being near the center of the opposite limits of its reciprocation. The improvement is the inclusion of a pressure responsive, one way valve interposed in the passageway. The one way valve is oriented to permit the passage of the working gas through the passageway from one space to the other in a direction opposite to a net leakage flow from one space to the other through the annular gap between the piston and cylinder and to prevent substantial flow through the passageway in the reverse direction.

Abstract: A vuilleumier heat pump device comprises: a hot-side heat pump (2) in which a hot side displacer (22) is housed in a hot side cylinder (21); and a cold-side heat pump (3) in which a cold side displacer (32) is housed in a cold side cylinder (31). Rods (23, 33) respectively connected to the displacers (22, 32) are connected to each other through a connection mechanism (4). In the vuilleumier heat pump device, a volume of the cold side rod (33) in a middle-temperature space (35) is adjusted. In this case, a rotation speed of a crank shaft (42) of the connection mechanism (4) is detected, a volume of the rod in a middle-temperature space (35) according to the rotation speed is calculated, and then the volume of the cold side rod (33) in a middle-temperature space (35) is adjusted so as to reach the calculated volume of the rod.

Abstract: A microminiature Stirling cycle engine or cooler is formed utilizing semiconductor, planar processing techniques. Such a Stirling cycle thermomechanical transducer has silicon end plates and an intermediate regenerator. The end plates are formed with diaphragms and backspaces, one end plate forming the expansion end and the opposite end plate forming the compression end, with the regenerator bonded in between. A control circuit apparatus is linked to the diaphragms for controlling the amplitude, phase and frequency of their deflections. The control circuit apparatus is adapted to operate the transducer above 500 Hz and the passages and the workspace, including those within the regenerator, expansion space and compression space, are sufficiently narrow to provide a characteristic Wolmersley number, which is characteristic of the irreversibilities generated by the oscillating flow of the working fluid in the workspace, below substantially 5 at the operating frequency above 500 Hz.

Abstract: In a multi-stage cold accumulation type refrigerator including a compressor disposed at an ordinary temperature, a helium gas as a common operating fluid to be compressed by the compressor, and one or more expansion chambers and cold accumulators of different temperature levels; a cold accumulating member of the cold accumulators is formed of an alloy or compound containing a rare earth metal, so that the efficiency of the refrigerator can be improved. Further, a heat generation quantity due to sliding resistance of a seal is set to be smaller than a theoretical generated refrigeration quantity to be obtained on the assumption of isothermal expansion in the expansion chambers, so that the refrigerating capacity can be improved. The refrigerator is applied to a cooling device for cooling a superconducting magnet, SQUID, superconducting computer, infrared telescope, etc.

Abstract: A rotary fluid displacement machine includes a stator having a wall provided with an inner wall face defining a work chamber; shaft bearings supported in the stator; a rotor; a rotor drive shaft secured to the rotor and supported by the shaft bearings; and vanes secured to the rotor for revolving therewith. The vanes divided the work chamber into at least two compartments. The rotor is provided with a gas channel having a first end opening to the exterior in a zone of one of the bearings and a second end opening to a surface of the rotor for communicating with the compartments.

Abstract: A double piston type pulse-tube refrigerator includes a compression cylinder, a compression piston reciprocably disposed within the compression cylinder, an expansion cylinder, an expansion piston reciprocating at preceding phase angle of about a quarter cycle and disposed within the expansion cylinder, a high temperature heat exchanger for cooling effectively working gas under compression stage interposed between the compression cylinder and the expansion cylinder, a regenerator connected to the high temperature heat exchanger, a low temperature heat exchanger connected to the regenerator and a pulse tube connected to the low temperature heat exchanger and the high temperature heat exchanger, a rotor with 4 magnetic poles constructed in a crank shaft and a ring with 4 magnetic poles corresponding to the rotor position disposed within a crank case for compensating torque unbalance.

Abstract: Disclosed is a low-temperature regenerative type refrigerator installed in a low temperature environment, in which a cooling water flow rate controller for adjusting the flow rate of cooling water automatically in accordance with the temperature of gas fed to an expansion unit from a compressor, is provided in a water cooling type cooler for cooling the compressor, to keep the temperature of the gas discharged from the compressor high to the extent of not deteriorating the function of a seal due to shrinkage or not causing convection or deflecting flow in a regenerator, whereby it is made possible to prevent the deterioration in the cooling efficiency of the regenerator which is caused by a lowering of the ambient temperature in the refrigerator installed place, and hence possible to prevent the deterioration of the refrigerating capacity as the entire refrigerator.

Abstract: A cryogenic cooling system having a mechanism for canceling vibration at a fundamental frequency and at harmonics thereof. The inventive system includes a first apparatus (28, 32) for cooling a mass. The first apparatus (28, 32) creates a vibration at a first frequency and a second frequency. In a typical application, the first frequency is a fundamental frequency and the second frequency is a harmonic of the first frequency. Often several harmonics are present. The invention includes a second apparatus (30, 34) for substantially eliminating vibration at the first frequency and a third apparatus (48, 50) for substantially eliminating vibration at the second frequency. The second apparatus includes a mass (30) and a motor (34) for driving same. The mass (30) is disposed to counter the vibration created by the first apparatus when the motor (34) is driven by a first current.

Abstract: A thermally operated refrigerator includes a hot space absorbing a heat from an outer heat source at a high temperature, an ambient space having a first portion and a second portion, a heat accumulator disposed between the hot space and the first portion of the ambient space for establishing a first fluid circuit in which an amount of operating fluid is filled, a hot displacer whose reciprocal movement establishes a periodical movement of the operating fluid in the first fluid circuit for rejecting the heat absorbed at the hot space to the first portion of the ambient space, a cold space absorbing a heat from a load at a low temperature, a cooler disposed between the cold space and the second portion of the ambient space for establishing a second fluid circuit in which an amount of operating fluid is filled, a cold displacer whose reciprocal movement establishes a periodical movement of the operating fluid in the second fluid circuit for rejecting the heat absorbed at the cold space to the second portion of t

Abstract: Gas displacement volumes of a high temperature chamber and a middle temperature chamber in a high temperature portion of a hot gas machine are different. Alternatively, a gas displacement volume of a low temperature chamber and a middle temperature chamber in a low temperature portion are different.

Abstract: A cold accumulation type refrigerating machine having a high refrigeration efficiency. Rotation output of a stepping motor is converted to a reciprocative motion of a displacement member carrying a cold accumulator and disposed within a cylinder in which first and second closed chambers are defined above and below the displacement member, respectively. A compressed gas discharged from a compressor is introduced into the second closed chamber through the cold accumulator upon opening of a suction valve and undergoes expansion within the second closed chamber, the gas being then fed back to the compressor through the cold accumulator upon opening of an discharge valve, whereupon one cycle of refrigerating operation is completed.

Abstract: Free piston Stirling coolers and engines are improved by a spring coupling the displacer to the piston and having a variable spring constant. Controllable variation of its spring constant permits controllable variation of displacer stroke, engine power output and cooler thermal pumping rate and thus the invention is useful for stroke limiting and load matching.

Abstract: There is disclosed a Stirling cooler comprising a compressor and a displacer apparatus. To prevent undesirable displacement of a displacer due to leakage of working fluid, the displacer apparatus of the present invention comprises a step portion provided at a lower end of a cylinder and formed with a through hole extending through it to permit work and buffer spaces to be in communication with each other and an actuating hole intersecting the through hole; a centering rod having a through hole formed therein and movably placed in the actuating hole of the step portion; a spring disposed rearwardly of the centering rod to apply a biasing force to the centering rod; and a displacer rod connected to the displacer and having a recess which is formed in an outer periphery of the rod and with which a forward tip of the centering rod is brought into contact.

Abstract: In a cryogenic refrigerator using a Gifford MacMahon (GM) cycle, a rotary valve device (RV) for controlling the supply and discharge of refrigerant gas with respect to the refrigerator (2) is adapted by a reversible motor (15) to be rotated in normal and reverse directions, and during the rotation in the normal direction, a cooling mode operation for producing cold by an adiabatic expansion is effected, and during the rotation in the reverse direction, a temperature-raising mode operation for producing heat by an adiabatic compression is effected. In order that the optimum efficiency can be obtained in each of the cooling mode operation and the temperature-raising mode operation, the timing of opening and closing of the rotary valve device (RV) with respect to the reciprocal movement of displacers (3a, 3b) during the rotation in the normal direction is made different from said timing during the rotation in the reverse direction.

Abstract: A cryogenic refrigerator comprises a compressor including a compressor housing within which a cylinder is mounted, and a piston reciprocal within the cylinder, and a cold finger including a low temperature cylinder within which a displacer is reciprocable, and a regenerater mounted within the displacer. A plurality of flat piston suspension springs include a plurality of spiral slits to provide a plurality of spiral arms deflectable as the piston is reciprocated within the compressor cylinder. A plurality of annular inner retainers are secured to the piston and adapted to sandwich the inner peripheral edges of the piston suspension springs. A plurality of annular outer retainers are secured to the compressor housing and include a plurality of projections extending inwardly from the outer ends of the spiral slits to sandwich the outer peripheral edges of the flat piston suspension springs.

Abstract: Disclosed is a low-temperature regenerative type refrigerator installed in a low temperature environment, in which a cooling water flow rate controller for adjusting the flow rate of cooling water automatically in accordance with the temperature of gas fed to an expansion unit from a compressor, is provided in a water cooling type cooler for cooling the compressor, to keep the temperature of the gas discharged from the compressor high to the extent of not deteriorating the function of a seal due to shrinkage or not causing convection or deflecting flow in a regenerator, whereby it is made possible to prevent the deterioration in the cooling efficiency of the regenerator which is caused by a lowering of the ambient temperature in the refrigerator installed place, and hence possible to prevent the deterioration of the refrigerating capacity as the entire refrigerator.

Abstract: A system for providing a cold environment which has a number of cooling stages with variable displacement volumes into which input fluid from a compressor flows in an input channel to and from the displacement volumes and output fluid flows in an output channel to the compressor. Volume changers vary the volumes of the displacement volumes and input fluid flowing to a first set of displacement volumes is pre-cooled by regenerative heat exchange and counterflow heat exchange and input fluid flowing to the final displacement volume is pre-cooled primarily by counterflow heat exchange. The volume changer at at least one of the stages is thermally decoupled from the input and output channels.

Abstract: A stirling engine including a heat exchanger having a displacer plate, which moves to and fro between two spaced parallel housing plates of the heat exchanger housing and which divides the housing into an expansion chamber and a compression chamber, cooling and heating devices associated with the displacer plate, distributed struts extending between the spaced parallel housing plates and penetrating the displacer plate, and a linear roller diaphragm which guides the displacer plate with respect to the end faces of the housing.

Abstract: The present invention relates to a magnetoelectric resonance engine combining in its construction and operation an Alpha-type Stirling cycle thermal machine and a magnetoelectric resonance mechanism having a broad application to both electric generators and electric heat pumps.

Abstract: A closed system for effecting cryogenic cooling. The system includes a cylinder which houses therewithin a piston disposed for reciprocation within the cylinder. The cylinder is in fluid communication with a closed reservoir. A conduit interconnects the reservoir to a first chamber defined at a first end of the cylinder. A branch passage diverges from the conduit to provide fluid communication between the conduit and a second chamber defined within the cylinder at a second end thereof. A first conduit segment is, thereby, defined between the intersection of the branch passage and the entrance of the conduit into the cylinder at the first end thereof, and a second conduit segment is defined between the intersection of the branch passage with the conduit and the entry of the conduit into the reservoir.

Abstract: Electronic chips are cooled to an efficient operating temperature by engaging their exposed planar surfaces with a heat sink assembly. The heat sink assembly is a part of the cold end heat sink of a thermoacoustic heat pump that utilizes either traveling wave or standing wave heat pumping to transport heat from the cold end heat exchanger to the warm end heat exchanger, utilizing a coaxial pulse tube refrigerator to pump or transport the heat from the electronic chips and the cold end heat exchanger.

Abstract: Vuilleumier type heat pumps and other thermal regenerative devices of the same type are improved by the provision of agitation and circulation of the working fluid within the working spaces for greater efficiency of heat exchange to/from these spaces. The circulation may be by means of fans, with electric motors, jet circulators, controlled direct exit of the working fluid from displacers, rotor blades located on a shaft operated from outside the device and other suitable means. The device may be single- or multi-unit. It may provide power to drive itself and/or for other uses.

Abstract: In a multi-stage cold accumulation type refrigerator including a compressor disposed at an ordinary temperature, a helium gas as a common operating fluid to be compressed by the compressor, and one or more expansion chambers and cold accumulators of different temperature levels; a cold accumulating member of the cold accumulators is formed of an alloy or compound containing a rare earth metal, so that the efficiency of the refrigerator can be improved. Further, a heat generation quantity due to sliding resistance of a seal is set to be smaller than a theoretical generated refrigeration quantity to be obtained on the assumption of isothermal expansion in the expansion chambers, so that the refrigerating capacity can be improved. The refrigerator is applied to a cooling device for cooling a superconducting magnet, SQUID, superconducting computer, infrared telescope, etc.

Abstract: A pulse tube refrigerating system includes a first space, a second space, a pulse tube disposed between the first and the second spaces so as to constitute a closed operating space in which an amount of operating fluid is filled, a driving device for establishing opposite phase fluctuations of the operating fluid by an expansion and an compression of the first space and the second space in alternative manner, a first set of a radiator and an accumulator disposed in the pulse tube so as to be located at a side of the first space, a second set of a radiator and an accumulator disposed in the pulse tube so as to be located at a side of the second space, a phase control oscillator disposed in the pulse tube and set to be be vibrated with a phase relative to the fluctuation of the operating fluid, and a control device for controlling the phase of the phase control oscillator relative to the fluctuation of the operating fluid.

Abstract: The present invention relates to a compression type heat pump which can obtain cooling and heating output by way of pressure changes in gases, comprising a casing member formed with a housing space outside a guiding spacer, which is constituted for first and second displacers to reciprocate up and down smoothly; a low temperature heat exchanger which generates cooling output, being housed in lower area of housing space of said casing member; a low temperature heat regenerator which emits and discharges heat, being placed on the upper area of said low temperature heat exchanger; an intermediate temperature heat exchanger which generates heating output, being placed on the upper area of said low temperature heat regenerator; an intermediate temperature heat regenerator which discharges or absorbs heat, being layed on the upper area of said intermediate temperature heat exchanger, and the lid fixed to the upper area of said casing member.

Abstract: A gas cycle engine for a small-sized, low-vibration and long-life refrigerator which is high in centering accuracy of a moving member and excellent in durability. In the gas cycle engine for such a refrigerator, a thermodynamic gas cycle is performed by using a moving member (2 and 3) disposed in a cylinder (1), supported by leaf springs so as to be movable in the axial direction of the cylinder and driven by a linear motor (9, 12 and 13), the leaf springs (4a and 4b) being made of an electrical conductor used also as current leads for supplying a current to the linear motor.

Abstract: A heat machine comprising a displacer reciprocating within a housing. The displacer incorporates first and second independent, co-axial, overlapping regenerators. A first working volume is formed between the displacer and the housing at a hot end of the heat machine. Second and third working volumes are formed between the displacer and the housing at a cold end of the heat machine. A partition separates the second and third working volumes. A gas flow path exists from the first working volume to the third working volume via the first regenerator, the second working volume, a gas path within the partition, and the second regenerator.

Abstract: A Vuilleumier heat pump comprises an inner cylinder, and an outer cylinder surrounding the inner cylinder. An annular space is created between the wall of the inner cylinder and that of the outer cylinder. At the top of the space, a heat regenerator is positioned. Under the heat regenerator, an intermediate level heat exchanger is positioned. At the bottom of the space, a cold regenerator is positioned. Between the intermediate level heat exchanger and the cold regenerator, a cold heat exchanger is positioned.

Abstract: A double stage Stirling cryogenic cooler with an IR Focal Plane array detector directly mounted on top of the cooler's expander second stage and with the radiation shield assembly mounted and cooled by the expander first stage to a temperature range of 200-100 K.

Abstract: A refrigerator comprising: a movable coil which is formed by winding a conductor on a cylindrical bobbin, and which, when a.c. current flows therethrough, reciprocates in a magnetic field produced by a magnetic circuit; a piston operatively coupled to the movable coil to reciprocate in a cylinder; a compression space, the volume of which is varied by the reciprocation of the piston; a cold cylinder; a displacer which divides the inside of the cold cylinder into a cold space and a hot space, and which reciprocates in the cold cylinder; a regenerator arranged in the displacer; and a changeover mechanism for short-circuitting the conductor wound to form the movable coil when the refrigerator is not in use.

Abstract: A free piston Stirling engine includes a displacer fitted in a cylinder so as to be able to reciprocate and defining an expansion chamber and a compression chamber in the cylinder, an operational sealing area leading from the expansion chamber to the compression chamber and interposed a heater, a regenerator and a cooler in order, a free piston disposed so as to be able to reciprocate toward a direction which crosses a direction of the reciprocation of the displacer and defining an operational chamber which is communicated with the compression chamber and a buffer chamber at its both ends and a linear generator disposed around the free piston and connected with a storage battery at its output terminal via an AC/DC converter having one or more transformation ratios. According to this constitution, even though the load is larger than the output of the linear generator transitionary, it is possible to supply stable electric power by use of the storage battery.

Abstract: A displacer-type Stirling engine includes buffer space provided in back of a power piston, and a front chamber in which a small-diameter piston provided on an end of a displacer rod is reciprocated. The buffer space and the front chamber are communicated by a conduit so that a fluctuation in pressure which develops in the buffer space is used as an auxiliary power source for driving the displacer rod.

Abstract: A cryogenic refrigerator cools a heat source by cyclically concentrating and diluting the amount of .sup.3 He in a single phase .sup.3 He-.sup.4 He solution. The .sup.3 He in superfluid .sup.4 He acts in a manner of an ideal gas in a vacuum. Thus, refrigeration is obtained using any conventional thermal cycle, but preferably a Stirling or Carnot cycle. A single phase solution of liquid .sup.3 He at an initial concentration in superfluid .sup.4 He is contained in a first variable volume connected to a second variable volume through a superleak device that enables free passage of .sup.4 He while restricting passage of .sup.3 He. The .sup.3 He is compressed (concentrated) and expanded (diluted) in a phased manner to carry out the selected thermal cycle to remove heat from the heat load for cooling below 1 K.

Abstract: A refrigerator having a pressurizing device, a coldness generating device for generating coldness by expanding a portion of operating fluid which has been pressurized by the pressurizing device and a fluid passage through which the operating fluid is, via a device to be cooled, again circulated to the pressurizing device after the residual portion of the operating fluid has been cooled by the coldness generating device. A regenerator type heat exchanger is disposed in the fluid passage through which the operating fluid passes, and a switch device switches the flow of the operating fluid in the fluid passage to the reverse direction at a predetermined time period.

Abstract: The invention relates to thermomechanical transducers drivingly linked to a linear motor or alternator, preferably a free piston Stirling engine in which the piston is drivingly linked to the field magnet of an alternator. There are symmetric and coaxial secondary magnets attached at opposite ends of the field magnet. The field magnet is polarized radially in one direction and the secondary magnets are polarized radially in the opposite direction. When the field magnet is displaced from a centered position, the secondary magnets have an oppositely directed axial net force exerted upon them. This causes a centering bias on the field magnet and therefore a centering of the piston in the Stirling engine or cooler.A secondary effect produced by the magnetic spring of the secondary magnets is amplitude limiting during load reduction on the Stirling engine. Amplitude limiting is a result of increased spring constant of the magnetic spring past a certain amplitude.

Abstract: A multi-stage cryogenic refrigerator utilizing the Gifford-McMahon cycle has an external regenerator in each stage. The external regenerators are vertically stacked and connected in series, so that expanding gas is allowed to flow through the regenerators without significant obstruction or turning motion. The lower regenerators operate at progressively lower temperatures. The packing material within each regenerator has a higher specific heat than that of the regenerator immediately above as determined at the operating temperature of the regenerator.

Abstract: A refrigerator comprising a first cylinder and a second cylinder which are coaxially arranged, a first movable coil and a second movable coil which are oppositely arranged in a magnetic flux produced by a magnet, and which can be reciprocated by applying an a.c.

Abstract: A Free-Piston Stirling cycle system includes a cylinder arranged within a sealed, pressurized housing. A power piston is arranged for reciprocation within or about one region of the cylinder, and a light-weight displacer, having a selected diameter is arranged for reciprocation within or about another region of the cylinder and defining with the cylinder a compression space and an expansion space. The power piston also defines with the cylinder, a gas spring space. A gas spring piston of preselected diameter couples the displacer with this gas spring space to establish a relative gas spring which generates a force to reciprocate the displacer by the relative motion between the displacer and the power piston. In accordance with this present invention the ratio of the diameter of the gas spring piston to the diameter of the displacer is made to be at least 0.50.

Abstract: A Gifford-McMahon cryorefrigerator is modified by using opposed sub-displacers which are sinusoidally reciprocated in opposite directions with respect to one another such that the force vectors of inertia created by the movement of the sub-displacers are cancelled out. The cancelling out of the force vectors should substantiallly reduce adverse affects associated with displacer banging.

Abstract: A refrigeration system includes a refrigerator having a compression portion having a compression cylinder and a compression piston moving slidably in the cylinder, a first heat excahnger, a regenerator and a second heat exchanger. An expansion portion has an expansion cylinder and an expansion piston moving slidably in the cylinder. A drive device drives the compression piston via a first rod and the expansion piston via a second rod. The compression cylinder includes a first large diameter portion where the compression piston is slidably moved and a first small diameter portion where the first rod is slidably moved, and the expansion cylinder includes a second large diameter portion where the expansion piston is slidably moved and a second small diameter portion where the second rod is slidably moved.

Abstract: A technique for producing a cold environment in a refrigerant system in which input fluid from a compressor at a first temperature is introduced into an input channel of the system and is pre-cooled to a second temperature for supply to one of at least two stages of the system, and to a third temperature for supply to another stage thereof. The temperatures at such stages are reduced to fourth and fifth temperatures below the second and third temperatures, respectively. Fluid at the fourth temperature from the one stage is returned through the input channel to the compressor and fluid at the fifth temperature from the other stage is returned to the compressor through an output channel so that pre-cooling of the input fluid to the one stage occurs by regenerative cooling and counterflow cooling and pre-cooling of the input fluid to the other stage occurs primarily by counterflow cooling.

Abstract: A method and apparatus for controlling the reciprocal movement of a free, gas-driven displaced in a cooling engine are disclosed. Mechanical stops in the form of a crank mechanism prevent axial overshooting of the gas-driven displacer in each direction. A uni-directional magnetic "detent" is established for the displacer at predetermined location beyond the top dead center and bottom dead center portions of the cooling cycle. Each uni-directional magnetic "detent" provides a magnetic retention force to hold the displacer from moving until a pre-determined pressure differential is established across the displacer's drive piston. The magnetic "detents" are formed by magnetic elements that operate in cooperation with the crank mechanism.