Sumitomo Heavy Industries, Ltd.

Qian Bao

Mingyao Xu

Takaaki Morie

A T A M De Waele

Koji Yamada

Akihiro Tsuchiya

Tian Lei

Changheng Liu

A rotary valve of a cryocooler includes a valve stator, a valve rotor, a rotation member that rotates the valve rotor around an axis with respect to the valve stator, and a rotor holder connected to the valve rotor so as to rotate around an axis together with the valve rotor, and forming a low pressure section having a pressure lower than an ambient pressure between the valve rotor and the rotor holder so as to reduce an axial force of pressing the valve rotor against the valve stator. The rotation member is connected to the rotor holder so as to rotate the valve rotor around the axis via the rotor holder. The rotor holder is disposed between the rotation member and the valve rotor in an axial direction, and is movable in the axial direction with respect to the rotation member.

Rotary valve of cryocooler and cryocooler

There is provided a cryocooler including a cylinder, a displacer disposed inside the cylinder and driven to reciprocate by a gas pressure, a collar rigidly connected to the displacer to reciprocate together with the displacer, a collar chamber divided into an upper section and a lower section by the collar, a second seal portion provided between the displacer and the cylinder to seal the lower section, a lower bumper provided in the lower section to mitigate interference between the displacer and the cylinder when the displacer is located at a bottom dead center, and a communication passage formed in the collar or in the collar chamber to ensure communication between the upper section and the lower section when the displacer is located at a bottom dead center.

Cryocooler

A cryocooler includes a first cylinder and a second cylinder, a first cooling stage, a second cooling stage, a radiation shield which is cooled by the first cooling stage, accommodates the second cooling stage, and shields the second cooling stage from radiant heat from an outside, and a temperature sensor which detects a temperature of the second cooling stage. A working gas is supplied into the first cylinder and the second cylinder to be expanded and is exhausted to the outside, an insertion hole through which an output cable of the temperature sensor passes through from an inside to an outside of the radiation shield is provided in the radiation shield, and the insertion hole is configured such that the radiant heat entering the radiation shield from the outside of the radiation shield is not directly radiated to the second cooling stage.

A cryocooler includes a cold head including a displacer movable in an axial direction, a drive piston connected to the displacer to move the displacer in the axial direction, an expansion chamber formed with the displacer, a piston drive chamber formed with the drive piston, a spool valve including a valve drive chamber, a spool that moves between a first position and a second position in response to a pressure of the valve drive chamber, and a pressure control mechanism configured to control a pressure of the valve drive chamber so that the spool reciprocates between the first position and the second position, and to generate a pressure fluctuation having an opposite phase to the pressure fluctuation in the expansion chamber in the piston drive chamber in synchronization with the reciprocation of the spool.

Cryocooler and flow path switching mechanism of cryocooler

A GM cryocooler includes a first cold head including a first displacer that is reciprocable in an axial direction, a first drive piston that drives the first displacer in the axial direction, and a first drive chamber that houses the first drive piston; a second cold head including a second displacer that is reciprocable in the axial direction, and a second cylinder that houses the second displacer; a first intake valve that is connected to both the first drive chamber and the second cylinder so as to supply working gas in parallel to the first drive chamber and the second cylinder; and a first exhaust valve that is connected to both the first drive chamber and the second cylinder so as to collect the working gas in parallel from the first drive chamber and the second cylinder.

GM cryocooler and method of operating GM cryocooler

A GM cryocooler includes a displacer that is reciprocatable in an axial direction; a displacer cylinder that houses the displacer; a drive piston that is coupled to the displacer so as to drive the displacer in the axial direction; and a piston cylinder that houses the drive piston and that includes a drive chamber of which a pressure is controlled to drive the drive piston, and a gas spring chamber which is airtightly formed with respect to the displacer cylinder and is partitioned from the drive chamber by the drive piston.

GM cryocooler

A GM cryocooler includes a valve portion which defines a valve group including a first intake valve, a first exhaust valve, and a pressure equalizing valve. A valve rotor of the valve portion includes a rotor plane which is in surface contact with a stator plane of a valve stator. The valve rotor includes a high pressure flow path which is open to the rotor plane to form a portion of the first intake valve, a low pressure flow path which is open to the rotor plane to form a portion of the first exhaust valve, and a pressure equalization flow path which is open to the rotor plane to form a portion of the pressure equalizing valve, and the high pressure flow path, the low pressure flow path, and the pressure equalization flow path are circumferentially arranged around a valve rotation axis on the rotor plane.

A cryocooler includes a displacer, a cylinder that forms an expansion space, a Scotch yoke mechanism configured to drive the displacer in a reciprocating manner, a first rod that extends from the Scotch yoke mechanism, a housing that includes an assist chamber, a rotary valve configured to switch between a state in which the expansion space and a discharge side of a compressor are connected and the assist chamber and a suction side of the compressor are connected and a state in which the expansion space and the suction side of the compressor are connected and the assist chamber and the discharge side of the compressor are connected, a motor configured to drive the Scotch yoke mechanism and the rotary valve, and an on-off valve configured to open and close a gas flow path through which the rotary valve and the assist chamber are connected.

A cryocooler includes a displacer capable of reciprocating in an axial direction, a cylinder that accommodates the displacer, a drive piston that drives the displacer in the axial direction, a drive chamber that accommodates the drive piston, a rotary valve that includes a first valve element that is one of a valve rotor rotatable around a rotary valve rotation axis and a valve stator, and a second valve element that is the other of the valve rotor and the valve stator, a reversible motor that is coupled with the rotary valve so as to rotate the rotary valve around the rotary valve rotation axis. The rotary valve includes a coupling mechanism that couples the first component and the second component with each other. The first relative angle is designed to cool the cryocooler, and the second relative angle is designed to heat the cryocooler.

Cryocooler and rotary valve unit for cryocooler

A cryocooler includes an expansion chamber, a cooling stage thermally coupled to the expansion chamber, the cooling stage including a first heat transfer block provided with a surface exposed to the expansion chamber and a first heat exchange surface disposed outside the expansion chamber and a second heat transfer block provided with a second heat exchange surface facing the first heat exchange surface, a refrigerant supply port installed in the cooling stage outside the expansion chamber, a refrigerant discharge port installed in the cooling stage outside the expansion chamber, and a refrigerant path fluidically separated from the expansion chamber, the refrigerant path being formed between the first heat transfer block and the second heat transfer block such that a refrigerant flows from the refrigerant supply port to the refrigerant discharge port along the first heat exchange surface and the second heat exchange surface.

Cryocooler with heat transfer blocks having fins

In a cryocooler for developing coldness of 4 K or lower by expanding helium, an expander expands high-pressure helium. A compressor compresses low-pressure helium returned from the expander, to generate high-pressure helium, and supplies the high-pressure helium to the expander. When helium temperature in the expander is 2.17 K or lower, the pressure of the low-pressure helium is equal to or higher than pressure given by a curve, in a helium state diagram in which the horizontal axis is temperature and the vertical axis is pressure, along which helium's volumetric thermal expansion coefficient is 0.

Cryocooler and cryocooler operation method

A rotary valve unit includes a rotary valve and a reversible motor. The rotary valve operates according to a cooling valve timing for cooling a pulse tube cryocooler when the reversible motor rotates in a forward direction and is operated according to a heating valve timing for heating the pulse tube cryocooler when the reversible motor rotates in a backward direction. The cooling valve timing is designed to generate a working gas pressure oscillation in a pulse tube and apply a first phase delay to a working gas displacement oscillation in the pulse tube with respect to the working gas pressure oscillation. The heating valve timing is designed to generate the working gas pressure oscillation in the pulse tube and apply a second different phase delay to the working gas displacement oscillation in the pulse tube with respect to the working gas pressure oscillation.

Pulse tube cryocooler and rotary valve unit for pulse tube cryocooler

A rotary valve mechanism includes a valve stator having a stator recessed portion and a valve rotor having a rotor recessed portion. The rotor recessed portion is formed in the valve rotor such that a rotor-recessed-portion front edge line passes through a stator-recessed-portion front edge line and the rotor recessed portion fluidally communicates with the stator recessed portion at a first phase of rotary-valve-mechanism rotation, and a rotor-recessed-portion rear edge line passes through a stator-recessed-portion rear edge line and the rotor recessed portion is fluidally separated from the stator recessed portion at a second phase thereof, and a shape of the rotor-recessed-portion front edge line coincides with a shape of the stator-recessed-portion front edge line such that the rotor-recessed-portion front edge line overlaps the stator-recessed-portion front edge line at the first phase.

Cryocooler and rotary valve mechanism

A regenerative refrigerator includes: a regenerator unit that precools a working gas; and an expander that cools the working gas by expanding the working gas precooled by the regenerator unit. The regenerator unit includes a zinc based regenerator member formed of zinc or an alloy containing zinc as a main component of the alloy. A first stage regenerator optionally includes a high temperature part including a first regenerator member and a low temperature part including a second regenerator member different from the first regenerator member. A second stage regenerator optionally includes a high temperature part including a second regenerator member and a low temperature part including a third regenerator member different from the second regenerator member. The second regenerator member optionally includes a zinc based regenerator member formed of zinc or an alloy containing zinc as a main component of the alloy.

Regenerative refrigerator, first stage regenerator, and second stage regenerator

In a cryocooler, a displacer includes an internal space, and a working gas flows through the internal space. A cylinder reciprocally accommodates the displacer, and an expansion space for the working gas is formed between the cylinder and a bottom portion of the displacer. A plurality of annular protruding portions are provided on a bottom surface of the expansion space such as to form a multiplex structure. A plurality of annular recessed portions are provided on the bottom portion of the displacer such as to receive the plurality of annular protruding portions.

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Nishitokyo, Japan

Qian Bao