Patent ID: 9523343
Filing Date: 2016-12-20
CPC Classification: F03B,F05B,Y02E

Claim Text:
1. A Francis runner for a hydraulic machine, intended to be passed through by a forced flow of water, comprising: a wheel which is rotationally symmetrical about an axis of rotation of the runner, a crown which is rotationally symmetrical about the axis of rotation and facing the wheel, a plurality of inwardly curved vanes, integral with the wheel and with the crown and each having a central edge in the vicinity of the axis of rotation and a peripheral edge, opposite the central edge, which extends between the wheel and the crown and which is intended to be passed through firstly by the flow of water when the hydraulic machine is operating in turbine mode, the peripheral edge of at least one vane being curved, with the concavity thereof facing toward the outside of the runner, the peripheral edge comprising: a first distance, measured between any point on the peripheral edge and a straight line passing through, on the one hand, a first connection point between the peripheral edge and the wheel and, on the other hand, a second connection point between the peripheral edge and the crown, the first distance being at a maximum at an intermediate point on the peripheral edge, and a radius of the intermediate point being less than a radius of the first connection point, wherein the radius of the intermediate point is less than a radius of the second connection point.