The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 27, 2007
Filed:
Aug. 10, 2004
Yasuyuki Enomoto, Chiba-ken, JP;
Toshiaki Suzuki, Kanagawa-ken, JP;
Sadao Kurosawa, Kanagawa-ken, JP;
Takanori Nakamura, Kanagawa-ken, JP;
Yasuyuki Enomoto, Chiba-ken, JP;
Toshiaki Suzuki, Kanagawa-ken, JP;
Sadao Kurosawa, Kanagawa-ken, JP;
Takanori Nakamura, Kanagawa-ken, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A Francis turbine with an improved shape of blades, which can reduce a circumferential velocity component generated in the flow downstream of the blades in a condition of a partial load operation, or reduce the secondary flow around the blades, is provided. A Francis turbine comprises a crown, a plurality of blades, and a band. The crown can rotate around a rotating axis. The blades are circumferentially arranged on the crown, each of which including an inner end as a trailing edge. The band is coaxially coupled with the crown by the blades. A distance Rc can be defined as a distance between the rotation axis and an end by the crown side of the trailing edge. A distance Rb can be defined as a distance between the rotation axis and an end by the band side of the trailing edge. The distance Rc and the distance Rb satisfy