Patent GB-190626178-A (GB)
Title: Improvements in Controlling Devices for Elastic Fluid Turbines.
Inventor: WILKINSON JAMES
Filed: 1906-11-19
Granted: 1907-10-31
Abstract: 26,178. Wilkinson, J. Nov. 23, 1905, [date applied for under Patents Act, 1901]. Elastic - fluid turbines.-Relates to governing and controlling mechanism for elastic-fluid turbines of the type described in Specifications Nos. 24,275 and 28,131, A.D. 1904, in which the nozzles are controlled by valves actuated by fluid pressure regulated by a governor-controlled movable steam jet. A series of nozzles 10, Fig. 2, are arranged in the head of the turbine, and are controlled by valves 8 actuated by spring-pressed pistons 11, exposed below to the supply pressure and above to the fluid pressure in a conduit 13. Any other suitable pressure - controlled valves may be used. The conduit 13 is connected by passages 16 to the chamber containing the controlling-jet. Fig. 3 is a section of the jet at right-angles to that shown in Fig. 2. The motive fluid enters a chamber 18, Figs. 2 and 3, through a passage 17. A shell 19, open at both ends, is fixed in the turbine head, and is provided with ports communicating with the space 18, and with lower ports communicating with spaces 27 to which the passages 16 are led. The controller reciprocates in the shell 19 and comprises a hollow cylindrical body 28, secured to a head 31 mounted upon a spindle 34 and co-operating with a mushroom piece 33, also mounted upon the spindle 34, to form an annular jet-orifice 35. Ports 32 in the part 28 are always more or less in register with the upper ports in the shell 19, so that there is constant communication between the fluid supply and the interior of the cylinder 28. The containing chamber terminates in a nozzle 22 leading to the turbine. The edge 38 of the lower part of the controlling- member forms a valve which seats itself against the lower edge 37 of the shell 19 when the former is in its highest position. When the turbine is overloaded, the controlling-device is lowered until the jet 35 is below the edge 37. Fluid from the space 18 then flows through the jet and into the nozzle 22 ; it also has an ejector effect on the spaces 27, so that the pressure above the valves 8 is reduced and the valves are opened. On raising the spindle 34, the jet 35 gradually comes above the edge 37 and then has an injector effect, so that the pressure above the valves 8 is increased and the valves are thereby closed. On still further raising the spindle 34, the valves 8 remain closed and the valve 38 is also closed, so that the nozzle 22 is throttled. Although the controlling-device may be operated by hand, it is preferably operated by a governor, as shown in Fig. 1. A governor 39 rocks a two-armed lever 47 through suitable linkage. This lever is pivoted to a bar 48, one end of which is pivoted on a fixed part of the mounting, the other end being pivoted to a sleeve 50, slidably mounted upon a lever 51, the upper end of which is hinged and the lower end engages the spindle 34 of the controlling-device. The lower end of the lever 47 is provided with a roller 53 which runs on a cam 54 driven by the governor shaft through bevel-gearing 57, 58. The movements of the governor are thus communicated to the controller spindle 34. The lever 47 may be pressed against the cam by a spring, but this is unnecessary in the arrangement shown. Pressure is supplied above the cylinder 28 by way of passages 65, Fig. 3, in the shell 19. Owing to the presence of the stem 34, there is a differential pressure and a constant tendency for the stem 34 to be pushed outwards. This pressure is communicated to the lever 51, which in turn exerts a downward thrust on the bar 48 carrying the lever 47. The central portion of the cam 54 is not circular in section, so that between the underloading and overloading position the spindle 34 is reciprocated, whereby the admission valves of the turbine are pulsated. Instead of this pulsating effect for intermediate load conditions, the several nozzle valves may be adapted to operate successively or respond in any desired manner to the pressure changes in the conduit 13.