GB681601A - Improvements relating to means for controlling liquid fuel pumps of internal combustion engines - Google Patents

Abstract

681,601. Gas turbine plant. ROLLS-ROYCE, Ltd. July 3, 1950 [April 5, 1949], No. 9320/49. Class 110(iii) [Also in Group XXIX] An internal-combustion engine, e.g. gas turbine, fuel system comprising a variable-swashplate pump 1 adjusted by a spring-loaded piston 12 subject to the pressure in a chamber 14 connected directly tb the pump outlet and to a control pressure in a chamber 16 connected, through a restricted passage, to the pump outlet and also to leak-off valves 25, 47, has the restricted passage constituted by two restrictions 50, 51 with the leak-off valve 25 connected to a point between the two restrictions and the valve 47 connected directly to the chamber 16. The arrangement permits of a substantial flow through the valve 25 during normal operation of the engine without sacrificing sensitivity of control by the valve 47 which opens only during abnormal running conditions. As shown, two pumps 1, 2 are driven through gearing 6 by a gas turbine engine and discharge into a common fuel delivery pipe 4 having a throttle 5. The valve 25 is loaded by a spring 29 and actuated by an evacuated bellows 31 subject to barometric pressure and a diaphragm 34 subject to the fuel delivery pressure. Two valves 47, one for each pump, are opened by a diaphragm 43 subject to the delivery pressure of a centrifugal impeller 37 upon the attainment of an excessive engine speed. The valves 47 may be operated at slightly different speeds. Specification 577,016. [Group XXIX], is referred to.