Patent GB-783716-A (GB)
Title: Governor device for gas turbine engines
IPC: F02C9/16
Filed: 1955-01-25
Abstract: 783,716. Gas turbine plant. BENDIX AVIATION CORPORATION. Jan. 25, 1955 [March 1, 1954], No. 2255/55. Class 110 (3). [Also in Group XXIX] A governor which controls the supply of fuel to a gas turbine engine and is adjustable to select an operating speed for the engine has means for automatically re-setting the governor as a function of one or more engine operating variables in such a manner as to maintain a substantially constant turbine inlet temperature or a substantially constant power output of the engine irrespective of variations in altitude and/or compressor inlet temperature. In an embodiment a centrifugal governor 64 operates a valve 28 between a fuel inlet conduit 24 and a delivery conduit 26, a valve 40 maintaining a substantially constant pressure differential across the valve 28. The compression of the spring 56 which loads the governor is varied by a lever 58 pivoted at 60 and engaged through an adjustable transmission element 116 by a servopiston 114. Fuel under pressure is supplied from the conduit 24 through a passage 126 and restriction 132 to a chamber 124 above the servo-piston and the pressure in this chamber, and consequently the position of the servopiston is determined by the relative sizes of the restriction 132 and a bleed 136 which is controlled by a valve member 112 carried by a lever 106 pivoted at 108 and connected to a lever 102 having cam followers 100, 148 engaging cams 88, 150 respectively. The cam 88 is rotated to select a required engine speed by a rack and pinion mechanism 90, 92 operated manually by levers 80, 84. The cam 150 is rotated through a rack and pinion mechanism 152, 157 by a servo-piston 158<SP>1</SP> having a control valve actuated by a bellows 155 subject to compressor inlet pressure or to a pressure within any stage of the compressor. The two cams 88, 150 together with a third cam 154 are moved axially by a lever 162 pivoted at 164 and actuated by a bellows 166 which is connected to a temperature-responsive element 168 at the inlet of the compressor or at a point within any stage thereof. The cams are three dimensional so that axial movement of them causes adjustment of the lever 102 and of a lever 176 which coacts with a collar 192 on an extension of the valve 28 to constitute a stop limiting opening movement of the valve during acceleration of the engine. The cam 154 is also angularly adjusted by a shaft 96 which is adjusted by a servo-mechanism as a function of engine speed. A further control of the valve 28 is effected by a rotary movement thereof brought about by a shaft 196 which has a bevel gearing connection 198 with a sleeve 202 having a pin and slot connection 188 with the valve 28. The shaft 196 is adjusted according to compressor discharge pressure by a servomechanism. The servo-mechanisms for actuating the shafts 96, 196 may be of the kind described in Specification 753,305. The mechanism 116 adjusts the maximum speed controlled by the governor whilst the idling speed is independently adjusted by a lever 206. The invention is applicable to single or multiple spool engines.