GB1411480A - Cryogenic refrigerator - Google Patents

Abstract

1411480 Refrigerating HUGHES AIRCRAFT CO 28 Feb 1973 [16 March 1972(2)] 9735/73 Heading F4H A refrigerator operating upon the Vuilleumier principle comprises a "hot" cylinder 12 having a heater 26 and a displacer 18, a "cold" cylinder 14 having a regenerator 21 with access ports 23 and 25, and a crank housing 16 havng a crankshaft 82. The housing 16 is attached to a motor (36, Fig. 1). A shaft 38 from the motor extends into the crank housing 16 and is rotatably mounted therein on bearings and is equipped with seals to prevent the escape of gas. Discs 40 and 42 are mounted on the end of the shaft 38 and are rotated thereby. An eccentric groove 46 is machined in disc 40, and a second eccentric groove 47 is machined in disc 42. Bearings 48 and 50 respectively are pressed into these grooves. Eccentric drive rings 52 and 54 are mounted on the bearings 48 and 50, to fill the grooves 46 and 47. The discs 40 and 42 are a close running fit within the cavity 56 of the crank housing. Guide bores 58, 60 are formed in bearing sleeves 62, 64 for the piston rods 66, 68; the rods having a flat machined surface 70 72 on one side thereof. Interconnection between the piston rods and the eccentric drive rings is accomplished by drive pins 78 and 80. A sliding and rotatable key 90 is provided in the housing 16. The key 90 can be turned so that a pinion 86 operates in a ring gear 88 to rotate the discs with respect to one another to alter the phase angle, i.e. the angular difference in the operating cycles of the displacers 18 and 20. In the embodiment shown, a phase angle of 105 degrees produces optimum cooling.