GB844083A - Improvements in or relating to centrifugal governors - Google Patents

Abstract

844,083. Centrifugal governors. PLESSEY CO. Ltd. Feb. 18, 1959 [Nov. 18, 1957; Feb. 12, 1959], Nos. 35877/57 and 4972/59. Class 57. [Also in Group XXIX] A centrifugal governor for the spill valve element 13 of the fuel control system of an engine, such as a gas turbine, comprises a governor member 18, 19 pivoted for movement in a longitudinal radial plane containing its axis of rotation and having the valve element coupled to it at a point thereon which lies approximately in the axis of rotation and in a plane passing through the pivot of the member normal to the axis. As shown applied to a geartype fuel pump, the governor member 18, 19, of L-shape cross-section, is connected by the arm 18 to a leaf-spring 20 which is secured to a member 10 mounted for rotation with the driven gear-shaft 7 of the pump. In operation, during normal running, the pressure of the fuel, which is in communication through a bore 7a in the shaft 7 with the valve element 13, is balanced by the effect of the centrifugal member loaded by a spring 14 mounted in a housing 15 and rotatable with the member. With an increase in engine speed, the member 18, 19 overcomes the pressure of the spring thereby opening the valve and returning excess fuel back to the pump delivery. In the modification shown in Fig. 2 the spring 14 mounted in a housing 15a can be pre-loaded by supplying a liquid under variable pressure through a pipe 31 and a bore 28 in an extension 27, to act upon a piston 26 in contact with the spring; a thrust bearing is fitted to take up some of the thrust reaction in the housing 15a and slots 15b are provided therein to facilitate the return of the excess fuel to the pump.