COLD HEAD FOR CRYOGENIC REFRIGERATING MACHINE

摘要

A cold head for cryogenic machines comprises a displacer (72, 76) mounted in a working chamber (38, 40, 46) of a housing (34, 36). The cold head also has a high-pressure connection (64) for supplying highly compressed refrigerant and a low-pressure connection (60) for discharging expanded refrigerant. Also provided is a control valve arrangement (58) for controlling the supply and discharge of refrigerant. According to the invention there is a bypass channel (80) connecting the high-pressure connection to the low-pressure connection.