GB191316557A - Improvements in and relating to Governing Mechanism for Elastic Fluid Turbines. - Google Patents

Abstract

16,557. Warwick Machinery Co., [General Electric Co.]. July 18. Regulating.-In turbines that may be required to run at speeds below their normal speeds, for example, turbines driving air-compressors, the governing-mechanism comprises a valve subject to the control of a centrifugal governor during normal operating conditions. In addition, a secondary speed governor is provided, this governor becoming operative when the speed falls below the range of the primary governor. At normal speeds, a centrifugal governor 11 operates the pilot valve 19 of the throttle valve 12 through link-work 14 ... 18. At speeds within the operative range of the governor 11, say 2 per cent above or below normal, the point 31 is stationary. A secondary governor of the fluid-pressure type comprises a gear pump 36, driven off the turbine shaft, by which oil is pumped from a tank 35 past a valve 42, adjusted by hand, through a pipe 41 to a pipe 45 leading to the bearings. A reducing-valve in the pipe 45 ensures a suitable feed pressure. Surplus oil passes back to the tank 35 by way of a pipe 43 provided with a relief valve 44. The pressure on the discharge side of the pump 36, depending upon the speed of the turbine and the adjustment of the valve 42, is transmitted through a pipe 40 to a diaphragm 23, the resistance of which to pressure depends upon the position of an adjustable spring 25. The diaphragm 23 transmits its movements through link-work 24, 29, 30 to the floating lever 16, and so controls the valve 12. When the governor 11 is operative, the speed of the turbine is such that the lever is fulcrumed at 31, while at lower speeds the lever 14 does not move and the lever 16 is consequently fulcrumed at 32, and the turbine is controlled by the governor 23.