Runner for francis type hydraulic turbine

摘要

There is disclosed a runner (10) for a Francis-type hydraulic turbine where each runner blade (13) has a outlet edge (16) comprising a deflected edge portion (110). The deflected edge portion (110) is located adjacent to the junction or attachment point (B) of the outlet edge (16) to the band (11) of the runner (10) to define a stress reducing tip extension portion (130) of the blade (13) adjacent the band (11). This tip extension portion (130) reduces stress concentration adjacent where the outlet edge (16) joins the runner band (11).