The new generation of Oxford linear compressors

The first generation of Oxford compressors were developed as part of a Stirling cycle cooler system for the ISAMS instrument carried aboard the UARS spacecraft (see the section on space cryocoolers). Since then a new type of compact linear motor and a new flexure spring design have been developed by the group for linear compressors with the aim of meeting the stringent requirements for high efficiency and low mass. The compressors are a key part of the High Efficiency Cryocooler (HEC) and have been jointly developed by the Cryogenic Engineering Group, Honeywell Hymatic, and TRW (now Northrop-Grumman Space Technology).
This design is considerably more rugged than previous machines and includes a fully controlled assembly and test process more suitable for repeated and consistent quantity production. Two of these balanced pairs were delivered by TRW to NASA/JPL for the IMAS project, and by 2002 at least 12 of the machines had been produced in a new ‘production-line’ process. New machines are also under continuous development to improve the range of sizes and powers available.