Patent GB-1069918-A (GB)
Title: Improvements in or relating to turbines,particularly kaplan turbines
Inventor: ALLAN MICHAEL BINGHAM
IPC: F03B3/14
Filed: 1963-11-26
Abstract: 1,069,918. Hydraulic turbines. DOMINION ENGINEERING WORKS Ltd. Nov. 26, 1963, No. 46664/63 Heading F1T. [Also in Division G3] The invention relates to a hydraulic turbine of the Kaplan type in which the rotor assembly comprises a hub portion in which the runner blades are mounted for angular adjustment, means being provided for angularly adjusting the runner blades comprising a pump disposed within the hub portion, means for driving the pump, a piston and cylinder assembly disposed within the hub portion and connected to receive fluid from the pump, the piston and cylinder assembly being connected to the runner blades whereby the angular position of the blades may be varied. In accordance with the invention, a hollow shaft extends axially from the hub portion and has an open end remote therefrom, the pump and the means for driving the pump being removable from the casing by withdrawing the pump and drive means axially through the hollow shaft. The rotor assembly shown comprises a hub portion 2 in which the rubber blades 3, 4 are adjustably mounted, each blade being connected by means of a link 7 to a crosshead 6 which is connected by a rod 8 to a piston 9 which is movable axially within a cylinder 10 by means of hydraulic fluid supplied either above or below the piston. The hub portion has secured thereto a casing 1 which constitutes a reservoir for hydraulic fluid, also at its upper end a hollow shaft 5 by which drive is transmitted from the turbine rotor to an electric generator. A control rod 11 extends through the hollow shaft 5, the control rod having a spool type control valve 21 secured thereto at its lower end. The control rod is movable axially, the corresponding movement of the valve 21 determining whether fluid is supplied either to the space above the piston 9 or to the space below the piston. A hydraulic fluid pump 23 is secured to the control valve 21 by means of the fluid supply duct 22, the pump having an inlet 24 and being driven by an electric motor 25 secured thereto. The pump and motor assembly 23, 25 together with the supply duct 22, control valve 21 and control rod 11 may be withdrawn for inspection through the hollow drive shaft 5. The runner blades are adjusted in coordination with movement of the wicket gates 13 as shown in Fig. 2, the wicket gates being moved by means of a hydraulic motor 17 the piston rod 16 of which carries a cam 18 which is connected by means of a cable 20 to the control rod 11. The control valve 21 is shown in detail in Fig. 3, the valve being shown in such a position that hydraulic fluid from the pump 23 passes through duct 22 to passage 26 in the valve body 21, the fluid then passing through port 30 in the piston rod 8 and passage 31 in the piston 9 to the upper side of the piston which is thereby moved downwardly so causing the runner blades to open. Fluid passes from the space below the piston through the passage 29 in the piston, port 28 in the piston rod thence through the passage 27 in the valve body 21 back to the reservoir. Downward movement of the piston ceases when the port 30 moves into alignment with the land 33 and port 28 moves into alignment with the land 32, this equilibrium position being shown in Fig. 4.