Patent ID: 7682134

Claim:
A Francis pump-turbine comprising: a runner provided with runner blades arranged around in a circumferential direction of a main shaft of the runner, each of the runner blades being supported by a band at a bottom side thereof in a blade height direction and supported by a crown at a head side in the blade height direction, wherein each of the runner blades is formed, at a trailing edge thereof, with a curved portion expanding to the main shaft when the turbine is in operation, wherein the curved portion has a maximum point with respect to a straight line connecting a crown-side trailing edge connecting end at which the trailing edge and the crown are connected and a band-side trailing edge connecting end at which the trailing edge and the band are connected, and wherein an angle α formed by a straight line connecting the maximum point and the crown-side trailing edge connecting end and a straight line connecting the maximum point and the band-side trailing edge connecting end is set to be within a range of α≦150°.