Patent ID: 9366244
Filing Date: 2016-06-14
CPC Classification: F04B,F25B

Claim Text:
1. A cryogenic refrigerator system comprising: a diaphragm pressure wave generator, the pressure wave generator comprising opposed first and second diaphragms that are each coupled at or toward opposite ends of a reciprocally moveable drive piston, the diaphragm pressure wave generator being driven by a drive system comprising: an operable actuator that generates a reciprocating motion output; a master piston that is driven by the output of the actuator in a reciprocating motion within a double-acting balanced master cylinder having two ends; and opposed slave pistons being reciprocally moveable within respective slave cylinders, each slave piston being arranged to act on a respective one of the opposite ends of the drive piston and each slave cylinder being operatively connected to a respective one of the two ends of the master cylinder for hydraulic fluid communication such that the master piston drives the slave pistons via hydraulic fluid moving between the master and slave cylinders in isolation from the two opposed first and second diaphragms such that the hydraulic fluid does not contact the diaphragms, the slave pistons having a larger cross-sectional area than the master piston such that reciprocating motion of the master piston at a low force and long stroke causes reciprocating motion of the slave pistons at a higher force and shorter stroke to thereby reciprocate the drive piston and opposed diaphragms to generate pressure waves; and one or more cryogenic refrigerators operatively connected to the diaphragm pressure wave generator such that they are driven by the generated pressure waves; and wherein the master cylinder and slave cylinders are directly coupled to each other such that they share the same cylinder cavities.