US 11,732,931 B2
Pneumatic drive cryocooler
Allen J. Bartlett, Chelmsford, MA (US); Matteo F. Salvetti, Chelmsford, MA (US); Sergei Syssoev, Chelmsford, MA (US); and Mark A. Stira, Chelmsford, MA (US)
Assigned to Edwards Vacuum LLC, Sanborn, NY (US)
Filed by Edwards Vacuum LLC, Sanborn, NY (US)
Filed on Nov. 16, 2021, as Appl. No. 17/527,750.
Application 17/527,750 is a division of application No. 17/046,148, granted, now 11,209,193, previously published as PCT/US2019/025945, filed on Apr. 5, 2019.
Claims priority of provisional application 62/655,093, filed on Apr. 9, 2018.
Prior Publication US 2022/0074628 A1, Mar. 10, 2022
Int. Cl. F25B 49/02 (2006.01); F25B 9/14 (2006.01); F25B 41/20 (2021.01)
CPC F25B 9/14 (2013.01) [F25B 41/20 (2021.01); F25B 49/02 (2013.01); F25B 2309/1428 (2013.01); F25B 2321/00 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A cryogenic refrigerator comprising:
a refrigeration volume having warm and cold ends;
a reciprocating displacer within the refrigeration volume;
a pneumatic drive volume at the warm end of the refrigeration volume;
a drive piston in the pneumatic drive volume coupled to the displacer;
refrigeration volume valving controlling cyclic supply and exhaust of a pressurized refrigerant gas to and from the warm end of the refrigeration volume;
drive valving providing supply and exhaust of drive fluid to and from the pneumatic drive volume to apply driving force to the drive piston;
magnets applying force to the piston in addition to the driving force applied by the drive fluid; and
an electronic controller controlling the drive valving with a drive control signal that varies through stroke of the drive piston to cause the drive piston to follow a programmed displacement profile through stroke of the drive piston.