Development of high performance moving-coil linear compressors for space Stirling-type pulse tube cryocoolers

• Development of moving-coil linear compressors in NLIP is reviewed.
• Design, material selection, manufacture, assembly and production are studied.
• Motor, clearance seal, flexure springs and flexible design are emphasized.
• Capacities of 0–500 W with motor efficiencies of 74.2–83.6% are achieved.
• Compressor types, characteristics and typical applications are presented.

This paper presents a review of the recent development of moving-coil linear compressors for space Stirling-type pulse tube cryocoolers in National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences. The design, manufacture and assembly methods are described with special emphases laid on linear motor, clearance seal, flexure springs, dual-opposed configuration and flexible design. Several key components are focused on and studied in a detailed way in terms of material selection, geometry design, configuration optimization, manufacture approaches and optimal assembly to achieve high efficiency, easy producibility, high reliability and long life. Experiences from the forerunners and the state-of-the-art approaches are reviewed and used for useful references, while our own successful experiences are emphasized and discussed in more detail together with some lessons learned. A series of compressors for space applications have been worked out with high confidence of reliability and long life expectation, which achieve input capacities of 0–500 W with motor efficiencies of 74.2–83.6%. Single-stage pulse tube cryocoolers driven by these compressors have already covered the temperature range of 25–200 K with cooling capacities varying from milliwatt levels to over 30 W. The commonly-used compressor types and purposes, performance characteristics and their applications in typical space cryocooler projects are also presented.