Fluid reaction surfaces (i.e. – impellers) – Rotor having flow confining or deflecting web – shroud or... – Radially extending web or end plate
Reexamination Certificate
2006-10-31
2006-10-31
Nguyen, Ninh H. (Department: 3745)
Fluid reaction surfaces (i.e., impellers)
Rotor having flow confining or deflecting web, shroud or...
Radially extending web or end plate
C416S243000, C416SDIG004
Reexamination Certificate
active
07128534
ABSTRACT:
A Francis turbine with a improved shape of blades to reduce the secondary flow around the blades and improve the hydraulic efficiency is provided. A Francis turbine comprises a rotating shaft, a crown, a plurality of blades and a band. The band is coaxially coupled with the crown by the blades and the rotating shaft, the crown, the blades, and the band as a whole are driven by water and rotate toward a turbine direction during a turbine operation. On a leading edge of at least one of the blades, a local maximum point exists between the crown and the band. The leading edge leans toward the turbine direction from the band connecting point, where the band and the leading edge are connected. And, a circumferential distance in the rotating direction between the band connecting point and the leading edge is the largest at the local maximum point.
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Enomoto Yasuyuki
Kurosawa Sadao
Sugishita Kaneo
Foley & Lardner LLP
Kabushiki Kaisha Toshiba
Nguyen Ninh H.
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