kaltkopf with one after gifford / mc mahon - principle of refrigerator.

摘要

The invention relates to a cold finger with a Gifford-McMahon cryogenic refrigerator (1) which has a cylindrical working space (3) in a casing (2) and a displacer (4) which is equipped with a central regenerator (5) and, during the operation of the cold finger, moves backwards and forwards between two extreme positions in the working space, and with a piston (6) fixed on one end face of the displacer and having a smaller diameter than the displacer (4) and a cylinder (7), associated with the piston (6), into which a conduit (22) for the supply of working gas opens; in order to obtain effective damping of the movement of the displacer in this cold finger, it is proposed that the displacer (4) be assigned means (21, 43 to 47) which exert on the displacer a force acting continuously in the direction of one of the two extreme positions of the movement of the displacer and that a restrictor (23) for obtaining damping be provided in the conduit (22) for supplying working gas to the cylinder (7). …IMAGE…