GB164475A - Improvements in or relating to the regulation of hydraulic turbines - Google Patents

Abstract

164,475. Seewer, P. W. March 5, 1920. Addition to 135,182. Regulating. - In regulating-devices for hydraulic turbines as described in the parent Specification wherein the water jet is regulated by governor-controlled fluid relays B<2>, F<2>, actuating respectively a nozzle valve B and adjustable guidevanes E, E<1> in the nozzle adapted to disperse the jet, a resetting-device is provided for the control valve H of the fluid relay F<2> to secure a more accurate, timing for the return of the guide-vanes E, E<1> to their normal position. As described in Specification 136,176, the governor N controls the relay B<2> through a valve D and controls the relay F<2> through a cataract valve H, H<2> responsive to rapid movements of the governor only. According to this invention, the guide-vane relay F<2> on moving to incline the guide-vanes carries with it a rod F<3> and cam F<4> which engages a roller P<1> and depresses a rod P, thereby re-setting the valve H so that oil can no longer escape from behind the piston F<2>. The valve H, thus reset, continues to descend under the influence of the spring H<1> of the cataract and opens the port communicating with the conduit D<7>. The master-control port D<8> is only opened when the nozzle-valve B has been adjusted or when the speed falls, whereupon oil under pressure is admitted to the relay F<2> and the guidevanes are returned to their normal position. A dash-pot R retards the rising of the rod P under the influence of the spring P<4>. An external device for adjusting the pivoted guide-vanes E. E<1> is also described. Instead of the guide-vanes being pivoted, they may be formed as shown at S<1> in Figs. 2 and 3, and moved axially in and out of a housing A<7> inside the nozzle.