Patent GB-190500958-A (GB)
Title: Improvements in Governing Mechanism for Elastic Fluid Turbines.
Filed: 1905-01-17
Granted: 1906-01-17
Abstract: 958. Warwick Machinery Co., [General Electric Co.]. Jan. 17. Elastic-fluid turbines. - Relates to governing- mechanism for elastic-fluid turbines. One or more valves control the admission of motive fluid to the first stage, or to successive stages, or to both ; these valves are operated by mechanism from the turbine shaft, and are controlled independently or simultaneously by the governor. In the arrangement shown in Fig. 1, the governor 5 is mounted on the turbine shaft 4, and consists of weights 6 opposed by a spring within the barrel of the governor Worm gearing 7, 8 actuates the shaft 9. This shaft carries a crank connected by a rod 10 to a lever 11 for imparting an oscillating motion to a shaft 20 carrying levers 12 which carry spring pawls or dogs 13, 14, Figs. 4 and 10, to act upon notches 33, 34 in cam-plates 15. A slot in each cam-plate embraces a roller 30 in the forked end 29 of a crosshead 27 connected to each valve-stem 22, the slot being so shaped that the valve 21 is open in the position shown, and closed when the roller 30 is at the opposite end of the slot. A spring 28 between each valve-stem and crosshead compensates for any inaccuracy of adjustment of the paits. The dogs 13, 14 are controlled by a pivoted shield-plate 16 formed as a bell-crank lever, and connected at its lower end, adjustably if desired, to the governor 5 by means of the rod 17 and lever 18, Fig. 1. According to the position of the arm of the plate 16 between the dogs, one or other of the dogs are lifted out of engagement with the notches 33, 34. In the position shown in Fig. 4, the dog 13 is raised out of engagement, the other 14 has forced the plate 15 into one extreme position, and the valve 21 is fully open. The shield-plates may be connected together by a rod or otherwise to ensure corresponding movements of the dogs. Notches 35 in the cam-plate are engaged by a spring 36 to lock the plate in either extreme position. The valve operating mechanism is shown separately in Figs. 8, 9, 10, and 11. The shaft 20 has a key extending from end to end, and carries as many levers 12 as there are valves. A single spring 31 or two separate springs act upon the dogs, which may be turned back and held out of aciion by the springs when desired. Each lever 12 has a long boss 32 to carry the cam-plate, Fig. 9, and this, in turn, has a boss 37 to carry the shield-plate 16. Each dog has a projection 41, Fig. 11, to engage the shield-plate, and is secured by a stud 42 to the lever 12. The dogs and shield-plates may be so arranged that, with the shield-plate in a central position, first one dog and then the other actuates the cam-plate, the valve thus being opened and closed a certain number of times per minute. The governing-mechanism is shown in Fig. 13 as applied to a vertical turbine 45 driving a generator 48. Steam is admitted to the turbine by the pipe 69. The worm-gearing 63, crank 64, and rods 66, 68 correspond to those shown in Fig. 1, and actuate the dogs 89, 90, which engage notches in the cam-plate. The shield-plate 59 is connected by the rod 58 to the pivoted lever 53. which is controlled by the governor 51, 52, a spring 55 being provided for synchronizing. The tension of this spring is regulated by means of an electric motor 56, worm-gearing 57, and a nut. When the invention is applied to multi-stage turbines, each valve may have a separate cam-plate, shield-plate, &c. The whole of the cam-plates are then connected to each other by rods, and the shield-plates are similarly connected. In another arrangement, the valves for each stage are in alinement, and are worked from one cam-plate and shield-plate. A further arrangement is illustrated in which there is one set of valves on one side of the turbine, and a second set on the opposite side, or at some other point, both sets being actuated from one source of power and controlled by a single governor. The parts may be set so that all the valves on one side are operated, and then those on the other side, or valves in each set may act alternately. In each case, the various parts are made interchangeable to facilitate repair.