Reduction of vibrations in miniature Stirling cryocoolers

The paper presents two approaches to reduce vibrations in miniature integral Stirling cryocoolers. Approaches were applied to cryocoolers developed and produced by LE-TEHNIKA. First, research done on a linear cryocooler is presented where vibrations were reduced with a passive damper, comprising of a vibrating mass and a spring. Importance of damper eigenfrequency and mass with regard to damper efficiency is discussed. Next, research done on a rotary cryocooler is presented where vibrations were reduced by using two balancing masses on a shaft. Vibrations were measured at different speeds. Measurements are presented as absolute values and in spectral domain, in both cases clear improvements can be seen.