Cryocooler

A cryocooler, comprising:

• a housing internally defining a low-pressure gas chamber;
• a valve stator fixed to the housing in the low-pressure gas chamber, and defining a variable pressure zone and a high-pressure zone between the housing and the valve stator;
• a valve rotor supported on the housing such as to be rotatable, around a valve rotational axis, with respect to the valve stator in the low-pressure gas chamber, and configured to interconnect the high-pressure zone with the variable pressure zone during a portion of a single cycle of rotation of the valve rotor, and to interconnect the low-pressure gas chamber with the variable pressure zone in another portion of the single cycle;
• a first seal member extending lengthwise around the valve rotational axis between the housing and the valve stator, being disposed adjacent to the high-pressure zone to seal the high-pressure zone, and encompassing a first surface area;
• a second seal member extending lengthwise around the valve rotational axis between the housing and the valve stator, being disposed adjacent to the variable pressure zone to seal the variable pressure zone, and encompassing a second surface area that is larger than the first surface area;
• and
• a third seal member extending lengthwise around the valve rotational axis between the housing and the valve stator, being disposed adjacent to the variable pressure zone to seal the variable pressure zone, and encompassing a third surface area that is larger than the second surface area.