Development of Small Vuilleumier Cooler for Space Use

Test Results of Long Term Operation

Abstract

A Vuilleumier cooler has the potential advantages of long-life operation with low mechanical vibration, and hence, it is expected for cooling spaceborne IR sensors. This paper describes the results from an endurance test and also causes of the cooler performance degradation. In the endurance test, it has been operated in an atmospheric environment for over 13, 000h. Cooling capacity was 1.6W at 80K at the beginning of life and it decreased to 0.8W at the end of life. After the test, the cooler was disassembled to investigate how the performance degradation had happened. We found that both crankpin bearing of a cold displacer and crosshead pin bearing of a hot displacer were broken. It is believed that cold head volume was reduced by former bearing breakdown and indicated work was reduced by later bearing breakdown. Both bearing failures brought cooler performance degradation.