Novel technique of vibration control for split Stirling cryocooler with linear compressor

Abstract

Ricor reports about a new, high performance miniature split Stirling cryocooler model K529H with integral dewar/cold finger, consisting of an electrodynamically driven linear piston compressor and pneumatically driven expander. The cryocooler was optimized to lift 1 W heat load, applied to a 80 K cold finger, with a reject temperature of 300 K and net power consumption of 25 W ac 60 Hz. High cryocooler performance, reasonable pricing, decreased total weight and dimensions were achieved due to the simplified compressor design of unbalanced single piston type. To meet the requirement of low vibration export from the cryocooler to its environment (less than 1 N rms at operational frequency) the compressor unit was suspended on the intermediate frame by means of the soft, lightly damped all-metal planar resilient elements. For the operational safety of cryocooler and its surrounding, the compressor excessive axial motion, originated by the high-level external vibration, was limited by elastomer bumpers with controllable dissipation of impact energy. Bumpers were installed on the intermediate frame with a certain axial clearance permitting impactless compressor operation in any space orientation while the cryocooler was not exposed to the external vibration. The bumped vibroisolation arrangement was optimized to minimize the impact acceleration Peak and rms levels.