GB777422A - Improvements in or relating to governor apparatus - Google Patents

Abstract

777,422. Automatic speed control systems. ROLLS-ROYCE, Ltd. March 23, 1954 [March 25, 1953], No. 8324/53. Class 38 (4). The speed of e.g. a gas turbine is controlled by a torque motor having a wound rotor and stator, supplied from a turbine driven alternator, and having a resonant circuit connected to the rotor or stator. Acceleration compensation may be provided. As shown, the alternator 10 supplies the stator and rotor coils 14, 16 of the torque motor device, and a series resonant circuit 18 is connected in series with the rotor. Movement of the rotor acts through linkage 31, 32 to operate a valve 33 controlling an oil pressure -operated piston 35 which (i) adjusts the fuel supply to the turbine through linkage 37, (ii) repositions the stator of the torque valve, and (iii) repositions the valve 33. Acceleration control is provided by a flywheel squirrelcage induction motor 38 also supplied from the alternator 10. Change in frequency causes stator reaction on the motor 38 to operate the valve 33 through linkage 40. Alternative arrangements.-(i) The stator coils of the torque motor 13 may be fed from tappings on the alternator (as shown by dotted lines 15A) to compensate for lack of phase quadrature due to iron losses in the torque motor; (ii) The rotor winding 16 may be energized by induction from the stator, Fig. 2 (not shown); (iii) a parallel resonant circuit may be used instead of the series type, Fig. 4 (not shown); (iv) a pair of valves such as 33 may be moved in opposite directions by the torque motor to control a differential oil pressure operated, Fig. 6 (not shown); (v) It is stated that the acceleration control may be effected by varying, e.g. the inductance in the resonant circuit instead of acting on the valve 33. Specification 777,423 is referred to.