GB1022136A - Improvements in or relating to rotary oil-circulation vacuum pumps - Google Patents

Abstract

1,022,136. Rotary vacuum pumps. SOC. ALSACIENNE DE CONSTRUCTIONS ATOMIQUES DE TELECOMMUNICATIONS ET D'ELECTRONIQUE 'ALCATEL'. Feb. 28, 1964 [March 1, 1963], No. 8399/64. Heading F1F. In a rotary oil-sealed vacuum pump, a valve controlling a duct between the pump chamber and an oil container in which the pump is immersed is held closed when the pump is inoperative to seal the pump and prevent oil rising in the suction pipes. As applied to a twovane type of rotary pump, the pump rotor shaft 10, Figs. 1, 3, (not shown) protruding through an end wall 4 of the pump casing carries a first offcentre pin 12 on which a disc 14 fitted with radial paddles 16 is pivotedly mounted and a second off-centre pin 13 which co-operates with an opening 15 in the disc to limit its movement. On rotation of the pump in the direction of the arrow f the disc is carried round by the pump rotor but due to the viscosity of the oil, rotation of the paddle 16 is opposed and the disc pivots about the pin 12 in the opposite direction limited by the pin 13 and the opening 15 so that the paddle lift a spring-loaded lever 6 carrying a valve head 5 to open a duct 2 connecting the oil container with the pump chamber. When the pump stops the lever 6 is moved downwardly by its spring 8, whence the valve head 5 closes the duct 2 and the disc 4 pivots about the pin 12 in the direction of the arrow f. The movement of the disc again being limited by the pin 13 and opening 15.