Linear Drive Stirling Cooler Technology

Abstract

Stirling cycle cryocoolers are used for cooling IR detectors in a number of military of military and commercial applications including missile guidance systems and night vision security systems. There is an ever increasing demand for longer and longer maintenance free operation of these coolers.

A critical component in the development of a long life, highly reliable Stirling cooler is the drive motor. Present state-of-the-art production 77K Stirling cryogenic coolers utilize rotary drive motors in a variety of configurations, brush/brushless, with AC and DC input power. In existing packaging concepts, these motors tend to be a source of particulate and gaseous contamination which reduces the overall system reliability. Linear drive technology offers the potential for significantly reducing the life limiting elements in the cooler design. Operational flexibility and low mechanical vibration are promising added features of this drive motor approach.

This paper reviews the status of linear drive technology developments at CTI-CRYOGENICS and describes mechanical designs and cryogenic performance for several sizes of Stirling coolers.