GB1050708A - - Google Patents

Abstract

1,050,708. Speed governors. ROLLS-ROYCE Ltd. April 2, 1965, No.14176/65. Heading G3B. [Also in Division F1] A proportional governor controlling spill fuel flow in accordance with the rotational speed of a gas turbine has a droop speed characteristic providing a substantially constant degree of stability at varying conditions of load and speed due to the provision in a spill valve 64 of parts 74 of varying cross-section and of a cam connection 101, 102 between the turbine speed control and the governor loading spring 91. Three flyweights 60 act on the spill valve through a thrust block 63 and are driven by a shaft 56 which also rotates the spill valve through epicyclic gearing 66, 67, 70 to prevent sticking. Fuel leaves the valve by way of parts 75 and an annular passage 76 leading to the fuel reservoir and also passes through parts 82, 83 to a space 84 and through parts 85 to a space at the left hand side of a piston 80 to provide pressure balancing. The cam connection 101, 102 rotates a spring abutment plate 87 about a bearing 86 to alter both the leverage and compression of the spring 91 with manual changes in speed setting. A non- return valve 72 is provided in the fuel supply line to the governor which may be driven through a gear-box from the three turbines of a ground effect aircraft having three fixed pitch lift fans and three variable pitch propulsion propellers. Each turbine has a low pressure compressor and turbine mounted on a shaft coaxial with a hollow shaft carrying a high pressure compressor and turbine; separate governors control the top speeds of the shafts by operation through a common ram of a bleed valve for the low pressure compressor. A fuel supply unit for each turbine receives its supply from a fuel pump, a filter, a backing pump and a heater and may be controlled by speed, compressor pressure and temperature.