Patent GB-190410578-A (GB)
Title: Improvements in and relating to Governors for Turbines and the like.
Inventor: EMMET WILLIAM LEROY
Filed: 1904-05-07
Granted: 1905-06-07
Abstract: 10,578. Emmet, W. L., and Junggren, O. May 8, A.D. 1903, [date applied for under Patents Act, A.D. 1901]. Steam &c. turbines. - Relates to speed and emergency governing- devices for elastic-fluid turbines and is applied to a turbo-generator of vertical type. The main shaft 80, Fig. 12, of the turbo-generator carries a centrifugal governor having adjustable dumb - bell weights 86 on T-shaped arms 84 acting on a carrier 91 controlled by an adjustable spring 88. The carrier is connected to a bell-crank lever 21 connected to the valve gear by a rod 22. An auxiliary governor is applied to each turbo - generator of a set to synchronize the turbines, and each governor has an independent electromotor 24 which drives worm gearing 107 so as to rotate a sleeve 96 adapted to vary the tension of a spring 106. The free end of the spring is connected by a collar device 100 to a rod pressing on one arm of the bell-crank lever. This action increases or diminishes the action of the primary governor and so synchronizes the various turbines of the set. A screwed projection 98 from the worm-wheel carries a sliding contact 115 adapted to disengage spring contacts 113 at the ends of its forward or backward travel, and so to cut out, or switch on, the current of the auxiliary motor. The rod 22 from the primary governor is connected by a rod 17, Fig. 4, to a rocking lever 16 connected at one end by rack and pinion gearing 52 or band gearing to a switch 15, and connected at the other end to a throttle valve 14. The turbine has three groups of nozzles, each nozzle being controlled by a self-closing valve, which is opened by the pressure fluid controlled by an electromagnetically-operated lift valve. The electromagnets 39 have circuits connected to the switch 15, Fig. 7, which contains a contact-cylinder 68 and brushes 58 formed of pairs of blades and adapted to be tilted by graduated cams 56<1> on a controlling-cylinder 59. The controlling-cylinder is rotated by the governoractuated gearing 52 and cuts in, or out, one nozzle at a time. Finer regulation is provided by the throttle valve 14 which acts in advance of the controller cylinder and controls the supply to the end nozzle, which is always the last to be cut in or not. The controlling-cylinder and contactcylinder are connected by a band so that the contact-cylinder is rotated and kept bright. To prevent racing, the turbine shaft 80 carries a weighted lever 128, Figs. 16 and 18, normally restrained by a spring 133, but under excessive speeds being forced outwards by centrifugal action and by the reversed action of the spring so as to strike a stud 130 connected by linkage 136 to a detent 137. When the detent is released, a weight 145 closes the main throttle valve 138, and also, through a lever 141, opens a relief valve which allows the steam shut in the steam conduit to escape into the condenser or atmosphere and stops the turbine more quickly. The weight and stud device may be varied. To stop the turbine if the flow of lubricant is interrupted, the lubricant passes through a vessel 125, Fig. 20, containing a perforated piston 156 which is pressed upwards by the fluid so that a contact 157 on its upper end completes the circuit 124 which allows the nozzle valves to be opened. If the flow of lubricant stops, a spring 160 depresses the piston and breaks the circuit so that all the nozzle valves close.