Patent classifications
F25B2309/001
Non-rotating flexure bearings with enhanced dynamic stability for cryocoolers and other devices
A system includes a device, a support structure, and a flexure bearing configured to connect the device to the support structure. The flexure bearing includes an outer hub and an inner hub, where the hubs are configured to be secured to the support structure and to the device. The flexure bearing also includes multiple sets of flexure arms connecting the outer hub and the inner hub, where each set of flexure arms includes symmetric flexure arms. The flexure bearing further includes multiple bridges, where each bridge connects one of the flexure arms in one set of flexure arms to one of the flexure arms in an adjacent set of flexure arms.
Method for improving gas bearing function at low thermal cooling power
A method for increasing working gas flow rate through gas bearings of a free piston, gamma configured Stirling heat pump to avoid failure of the gas bearings while maintaining thermal cooling power. The Stirling heat pump lifts heat from a storage chamber and has pistons that are driven in reciprocation at an operating frequency by linear electric motors. A temperature control maintains a steady state storage chamber temperature by sensing storage chamber temperature and modulating piston amplitude. The invention comprises (a) driving the pistons with linear electric motors that are driven by a variable frequency, AC power source; (b) sensing the pistons' amplitude of reciprocation; and (c) if the sensed piston amplitude is less than a selected piston activation amplitude, increasing the frequency of the AC power source to increase the Stirling heat pump's operating frequency. That decreases thermal cooling power which causes the temperature control to increase piston amplitude.
CRYOGENIC REFRIGERATOR OF STIRLING TYPE WITH DUAL-PISTON COMPRESSOR AND CONCEALED EXPANDER
A Stirling type cryogenic refrigerator device includes a dual-piston compressor and a pneumatic expander, wherein some of the pneumatic expander is concealed within the body of the dual-piston compressor.
PULSE TUBE CRYOCOOLER WITH AXIALLY-ALIGNED COMPONENTS
A pulse-tube cryocooler includes a compressor piston that is axially aligned with a pulse tube. The compressor piston is an annular piston that has a central hole around its axis. An inertance tube, connected to one end of the pulse tube, runs through the central hole in the compressor piston. The cryocooler also includes a balancer that moves in opposition to the compressor piston, to offset the forces in moving the compressor piston. The balancer may also be axially aligned with the pulse tube, the annular piston, and the inertance tube. The alignment of the compressor piston, the pulse tube, and the inertance tube aligns the forces produced by movement of fluid within the cryocooler. This makes it easier to cancel mechanical forces produced by the cryocooler in operation, since all (or most) of the forces are in a single axial direction.
CRYOGENIC REFRIGERATION DEVICE
Cryogenic refrigeration device comprising a working circuit intended to cool a working fluid circulating in the said circuit, the working circuit comprising, arranged in series in a loop: a compression portion, a cooling portion, a portion with valve(s), an expansion portion and a reheating portion, in order to subject the working fluid to a recuperative working cycle comprising compression, then cooling, then expansion and then reheating to prepare for a new cycle, wherein the compression portion comprises at least one compressor having a linear piston driven by a linear motor, the expansion proportion comprises at least one expander with a linear piston, the portion with valve(s) comprises at least one regulating valve linearly actuated by a linear motor and controlled in order to supply or extract the working fluid from the at least one expansion piston.
MECHANICAL VIBRATION-ISOLATED, LIQUID HELIUM CONSUMPTION-FREE AND EXTREMELY LOW TEMPERATURE REFRIGERATING SYSTEM
The present disclosure relates to the technical field of cryogenic cooling. In particular, the present disclosure relates to a mechanical vibration-isolated, liquid helium consumption-free cryogenic cooling device. The system according to some embodiments of the present disclosure comprises: a closed-cycle cryogenic cooling system, a helium heat exchange gas cooling and vibration isolation interface system, a cryogenic throttle valve cooling system, and a temperature feedback control system. The cryogenic cooling system provided by the present disclosure can achieve extremely low temperatures, as low as 1.4 K (based on helium-4 medium) or 0.2 K (based on helium-3 medium) without the need for the consumption of liquid helium. The disclosed cooling system can also efficiently isolate intrinsic mechanical vibrations of the closed-cycle cooling system. The disclosed cooling system can achieve variable temperature regulation through the temperature feedback control system. The disclosed cooling system can be compatible with ultra-high vacuum environments for high-temperature baking.
GM cryocooler
A GM cryocooler is furnished with: a first cold head including a first displacer and a first cylinder; a second cold head including a second displacer and a second cylinder and being disposed opposing the first cold head; a common drive mechanism for driving axial reciprocation of the first displacer and the second displacer; and a working gas circuit for generating between the first cold head and the second cold head a pressure differential that assists the common drive mechanism.
CRYOCOOLER AND MAGNETIC SHIELD STRUCTURE OF CRYOCOOLER
A cryocooler includes: a magnetic shield axially extending along a second-stage cylinder from a second-stage cooling stage outside the second-stage cylinder and disposed separated from a first-stage cooling stage by an axial separation distance, wherein an annular space open to a helium atmosphere is formed between the second-stage cylinder and the magnetic shield, and the axial depth of the annular space is longer than the axial separation distance; and a convection suppression member, for suppressing axial convection of helium gas in the annular space caused by temperature difference between the second-stage cylinder and the magnetic shield, is disposed in the annular space and is of longer axial length than the axial separation distance.
CRYOCOOLER WITH CONCENTRIC MOVING MECHANISMS
A cryogenic cooler includes a housing, and first, second, and third actuators. The first actuator includes at least one first voice coil and at least one first magnetic circuit, the at least one first voice coil of the first actuator configured to drive a compressor piston, the first actuator causing vibrations to the housing when driving the compressor piston. The second actuator includes at least one second voice coil and at least one second magnetic circuit, the at least one second voice coil of the second actuator configured to reduce the vibrations to the housing caused by driving the compressor piston. The third actuator includes at least one third voice coil and at least one third magnetic circuit, the third actuator configured to drive a displacer piston. The compressor piston, balance mechanism, and displacer piston are concentrically formed within the cryogenic cooler.
COMPACT INTEGRAL STIRLING LINEAR CRYOCOOLER
An integral cryocooler includes a cold finger within an elongated space defined inside an elongated housing. A tip of the cold finger freely protrudes outside an opening at an exterior end of the housing, and a root of the cold finger is supported in a cantilevered manner at an interior end of the housing. A cryocooler cover sealingly connected to the housing forms a pressure vessel. A ferromagnetic mover is coaxially fixed to a movable capped cylinder that is located within the pressure vessel and surrounds the interior end of the housing to form a compression space. A stator is located outside the pressure vessel and includes two cylindrical permanent magnets with opposite and axial magnetization that surround a driving coil. When an alternating electrical current flows through the driving coil, the movable capped cylinder is moved axially back and forth to alternately compress and expand the compression space.