GB594504A - Improvements in and relating to speed governing mechanism - Google Patents

Abstract

594,504. Fluid-pressure servomotorcontrol systems: BRITISH THOMSONHOUSTON CO., Ltd. Aug. 1, 1945, No. 19734. Convention date, Aug. 7, 1944. [Class 135] [Also in Group XXVI] An overspeed governor comprises a flyball housing 59, Fig. 4, from which a spindle actuated by the flyballs projects into a pocket 60 of another housing connected to the first, interconnected inlet and outlet passages 12, 13, respectively, through which a speed controlling fluid can flow, and a valve 22 to control such flow; and the ends of shafts 21, 17 connected, respectively, to valve 22 and to a lever 16 acted upon by the governor spindle project into a further pocket 67 where they are 'interconnected by a lever mechanism. The invention may be applied to a gas turbine plant in which valve 22 controls a byepass from the fuel supply to the burners back to the inlet of the fuel pump. The flyball mechanism comprises two bowed springs of which one, 33, Fig. 2, is clamped to a frame 35 and the ends of the springs are connected by the flyweights. The centre part of the free spring 'acts on a spindle 15 which engages an adjustable screw 15a on a spring-loaded lever arm 16, the latter actuating a servo pilot-valve 24 through a lever arm 18, link 19, and floating lever 20. Pressure fluid controlled by valve 24 to actuate the servo piston 25 is derived from the fuel supply pipe 12 and passed through a filter 31. Valve 22 is actuated by the servo-piston through a lever 29 and the shaft 21, the latter being connected to the floating lever 20 by an eccentric pin 20a so as to provide a recentring device for the servo pilot-valve 24. The servo-piston and pilot-valve are situated underneath pocket 67.