GB461509A - Improvements in or relating to rotary pumps - Google Patents

Abstract

461,509. Rotary pumps. JOHNSON. J. P. Aug. 17, 1935, No. 23194. Convention date, March 12. [Class 110 (ii)] A rotary pump of the type shown is designed to supply fuel to a carburetter at a constant pressure despite variation in pressure at the inlet port 14 where fuel enters the pump. The rotor 21 has sliding vanes 24 which bear at their inner ends on a loose roller 26, and at the tips on a liner 17 which extends between two end plates 16, 20, and is secured by a pin 143 against turning. A byepass valve 52 is placed between passages 48, 50, communicating respectively with the suction and delivery sides of the pump, to allow surplus fuel to be returned to the inlet side. The valve has an extension 53 in a cylinder acting as a dashpot. A spring 55 bears on a sleeve end 57 resting on the valve 52, and the spring pressure may be adjusted by means of a nut 65, and secured by a lock-nut 61. The preferred delivery pressure of the pump is 3¢ lbs. per square inch. A bellows 67 is mounted at the lower end on the sleeve 57 and at the upper end to a cover plate 58. The lower outer end is subjected to the pressure of the suction side of the pump, and its area is equal to that of the valve seat 47. The inside of the bellows is open to the atmosphere through a hole 68. In the event of the bellows breaking, an auxiliary hand pump may be operated to supply fuel to the upper side of a partition 46, and delivered past spring-pressed ball valves 70. The control mechanism is mounted in a housing 43 which may be removed and reversed from the position shown, if the pump is to be operated in the opposite direction. The pump is driven through members 34, 37 which are pressed apart by a spring 38. The adjacent ends of the parts 34, 37, have interengaging driving formations. The housing 11 is preferably made of aluminium and the rotor 21 and liner 17 of hard steel.