Patent ID: 7195459
Filing Date: 2007-03-27
Classification: F03B,Y02E,Y10S

Abstract:
1. A Francis turbine, comprising: a crown, which can rotate around a rotation axis; a plurality of blades circumferentially arranged on the crown, each of which including an inner end as a trailing edge; and a band coaxially coupled with the crown by the blades; wherein a projected profile of the trailing edge on a meridian plane, which is a plane including the rotation axis, is formed on an inner side of a straight line that connects both ends of the trailing edge on the meridian plane, wherein a distance Rb can be defined as a distance between the rotation axis and an end by the band side of the trailing edge, wherein the maximum distance s can be defined as a maximum distance between the straight line and the trailing edge on the meridian plane, wherein the distance Rb and the maximum distance s satisfy