The present disclosure relates to a cryogenic apparatus (300, 400, 500), comprising: at least one first temperature change mechanism (310, 410) connected to a sample stage (20) and configured to change a temperature at the sample stage (20); at least one second temperature change mechanism (320, 420, 520, 522) different from the at least one first temperature change mechanism (310, 410), wherein the at least one second temperature change mechanism (320, 420, 520, 522) is connected to the sample stage (20) and configured to change the temperature at the sample stage (20); and a controller. The controller is configured to: operate the at least one first temperature change mechanism (310, 410) in a first temperature range (A); operate the at least one second temperature change mechanism (320, 420, 520, 522) in a second temperature range (B) different from the first temperature range (A); and operate both the at least one first temperature change mechanism (310, 410) and the at least one second temperature change mechanism (320, 420, 520, 522) in a third temperature range (C) between the first temperature range (A) and the second temperature range (B).

A cool air supplying apparatus includes a swash plate shaft connected to a motor and extending in a predetermined axial direction; a compression swash plate obliquely coupled to the swash plate shaft; a compression piston configured to reciprocate in the axial direction by the rotation of the compression swash plate; a compression cylinder in which a working fluid is compressed by the compression piston, an expansion swash plate obliquely coupled to the swash plate shaft; an expansion piston configured to reciprocate in the axial direction by the rotation of the expansion swash plate; and an expansion cylinder arranged with the compression cylinder in the axial direction and configured to expand a working fluid compressed by the compression cylinder; and the compression swash plate and the expansion swash plate are installed in the swash plate shaft with a predetermined phase difference.

A cryogenic cooling system includes a gas circulation source; a cryocooler that cools a cooling gas; a cooling gas flow path that causes a cooling gas to flow from the gas circulation source to the object to be cooled; and a control device that controls the gas circulation source so as to execute initial cooling of the object to be cooled according to a prescribed flow rate pattern. The prescribed flow rate pattern is predetermined such that the cooling gas flows through the cooling gas flow path at a first average flow rate, and the cooling gas flows through the cooling gas flow path at a second average flow rate. The second average flow rate is smaller than the first average flow rate such that the cooling capacity of the cryogenic cooling system is increased.

Techniques are disclosed for systems and methods to reduce the overall physical size of and mechanical vibrations within a cryocooler/refrigeration system configured to provide cryogenic and/or general cooling of a device or sensor system. A refrigeration system includes an annular linear compressor configured to generate a compression wave of working gas for the system. The annular linear compressor includes an annular cylinder head with a pressure plate and a neck protruding from one side of the annular cylinder head, a compressor housing configured to mate with the pressure plate and the neck of the annular cylinder head and form a sealed cavity therebetween, and an annular cylinder assembly disposed within the sealed cavity and about the neck of the annular cylinder head. The annular cylinder assembly includes an annular piston assembly disposed within an annular cylinder of the annular cylinder assembly.

A Stirling cooler structure having multiple cooling modules includes at least one power unit, a pipeline, a plurality of Stirling cooling modules, and at least one piezoresistive unit. The power unit includes a cylinder and a piston. The pipeline is connected to the cylinder. The Stirling cooling modules each include a pipe and a passive displacer. The passive displacer is reciprocally, movably disposed in the pipe to partition the pipe into a cold end and a hot end. The hot end is connected to the pipeline. The piston is driven by an electric motor for a compressed air to flow through the pipeline to the hot end and then flow to the cold end through the passive displacer, such that the cold end absorbs ambient heat. The piezoresistive unit is selectively disposed between the Stirling cooling modules and the cylinder.

A circulating loop for transporting refrigeration to a remote location is connected serially between a Gifford-McMahon (GM) or GM type Pulse Tube cold head and the compressor. Either high pressure gas from the compressor can flow through the remote heat station before returning to the cold head or low pressure gas can flow from the cold head to the remote heat station before returning to the compressor. A first fraction of gas, which may include all of the gas at ambient temperature, enters a counter-flow heat exchanger, is cooled by the cold head, flows to the remote load, and then returns to ambient temperature as it flows through the counter-flow heat exchanger. The high or low pressure line may have a circulation control valve that diverts a second fraction of gas to flow directly between the cold head and compressor. A controller adjusts the circulation control valve to optimize the cooling of the load.

In a gamma free-piston Stirling cooler driven by linear electric motors, a motor operating frequency for consuming minimum electric power is detected and a different motor operating frequency that delivers maximum thermal cooling power is detected. The frequencies are detected by varying the operating frequency in small steps while sensing (1) the motor power input to maintain a steady temperature or (2) the thermal cooling power of the Stirling cooler. A mode detection routine detects whether the appropriate freezer operation is the electric power minimization mode or the thermal cooling power maximization mode based upon the current thermal conditions in the freezer. When the freezer is sufficiently cold, the pistons of the Stirling cooler are driven at the minimum electric power consumption frequency. When the temperature is, or is likely to become, too warm, the pistons of the Stirling cooler are driven at the maximum thermal cooling power frequency.

Techniques are disclosed for systems and methods to control operation of a cryocooler/refrigeration system to provide cryogenic and/or general cooling of a device or sensor system. A cryocooler controller includes a motor driver controller configured to generate motor driver control signals based on operational parameters corresponding to operation of a cryocooler controlled by the controller, and a motor driver configured to generate corresponding drive signals to drive a motor of the cryocooler. The motor driver includes a first stage with a first pair of switches coupled serially between an input of the motor driver and a ground of the motor driver, a second pair of switches coupled serially between an output of the first stage and the ground of the motor driver, and an inductor coupled between the first and second pairs of switches, where operation of each switch is independently controlled by the motor driver control signals.

A compressor unit of a refrigeration device includes a compression chamber. A piston is configured to be moved back and forth along an axis to alternately compress and decompress a gas in the chamber. An electromagnetic actuator is configured to drive the piston and includes a stator assembly with a driving coil that is coaxial with the axis and two permanent ring magnets that are radially magnetized identically to one another in a plane that is perpendicular to the axis. The ring magnets are located on opposite sides of the driving coil along the axis. A ferromagnetic shaft is elongated parallel to the axis and connected to the piston. When an alternating electrical current flows through the coil, the shaft is magnetized such that the shaft is alternately attracted to one of the ring magnets and repelled by the other to drive the piston back and forth.

A cryocooler includes: a housing furnished with a housing bottom surface; a displacer furnished with a displacer upper surface between the housing bottom surface and which an upper gas chamber is formed, and being enabled to reciprocate axially with respect to the housing; a housing gas flow path formed in the housing and opening onto the upper gas chamber; a displacer upper gas flow path formed in the displacer and opening onto the upper gas chamber; and a gas-guiding flow channel formed in at least either the housing bottom surface or the displacer upper surface constituting a portion of the upper gas chamber, and interconnecting the housing gas flow path and the displacer upper gas flow path when the displacer is positioned at top-dead center in its axial reciprocation.