Patent ID: 8684694

Claim:
A wheel of a Francis type for a hydraulic machine designed to pass a forced flow of water, the wheel comprising: a band that is circular and symmetrical about an axis of rotation of the wheel; nine curved blades that extend from the band and each curved blade having an outside peripheral edge and an inside central edge; the band is connected to the inside central edges of the blades at connection points that are situated on a common circle that is centered on the axis and the band is connected to the outside peripheral edges of the blades at connection points that are situated on two distinct circles that are centered on the axis; wherein the blades include six long blades and three short blades, the long blades having connection points situated on a first of the two distinct circles, and the short blades being disposed on the band with an angular spacing of 120Â° and having connection points situated on a second of the two distinct circles having a diameter smaller than a diameter of the first circle.