High Performance Flight Cryocooler Compressor

P.B. Bailey (1), M.W. Dadd (1), N. Hill (2), C.F. Cheuk (2), J. Raab (3), E. Tward (3)

  1. Department of Engineering Science, University of Oxford, Parks Road, Oxford, OX1 3PJ, UK.
  2. The Hymatic Engineering Company, Ltd. Redditch, UK.
  3. TRW, Redondo Beach, CA, USA

In this paper we report on the development of a next generation flexure bearing compressor which features high efficiency, high capacity per unit mass, enhanced producibility and ease of integration into payloads. The compressor was developed for the 95K High Efficiency Cryocooler programme.

The compressor achieved low mass by using small diameter flexure springs and having a new compact design of magnetic circuit which also has the advantage of being self shielding, thus reducing the radiated magnetic field.

A pair of compressors mounted back to back and driven in anti-phase provides low levels of self-induced vibration, which is further improved by the rigidity of the motor and the characteristics of the new motor and spring designs.

Its ease of integration results from its compact size and the incorporation of a single thermal and mechanical mounting interface in its centreplate. The centreplate incorporates heat spreading both internally for removing compressor heat as well as for spreading the heat to the radiator to which it can be attached.

Producibility has been achieved by transferring the processes developed for manufacturing a similar Oxford designed long life tactical cryocooler.

The compressors are being manufactured by Hymatic to a design which has evolved from earlier machines made by Oxford University. TRW will integrate the compressors into the flight qualified 95K High Efficiency Cryocooler which will be delivered to AFRL in October 200.