AXIAL-FLOW HYDRAULIC TURBINE RUNNER Russian patent published in 1999 - IPC

FIELD: hydraulic-turbine manufacture for small hydroelectric power plants. SUBSTANCE: runner-to-shaft joint is made of parts enabling creation of considerable pre-stress conditions. Blade flanges have elongated tails in the form of extension nuts mounted with their fitted bands on external part of runner case holes. External taper part of tail gradually turns into second fitted band and terminates in polyhedron. Fitted onto the latter is disk with mating inner bore locked by means of bent collar in runner case slot and used to secure bracing bolt driven in central threaded hole of blade flange tail to secure flange to case. Shaft flange restring on inner end of runner case has taper bead and is threaded in center. Stud is turned into threaded hole and secured on other end with stretching nut that has conical external generating line turning into case-supporting surface with pressure center coinciding with that of runner case external end. EFFECT: improved operating reliability and power capacity due to reduced hub ratio. 2 cl, 1 dwg