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:
Apr. 03, 2007
Filed:
Jun. 15, 2004
Yasuyuki Enomoto, Chiba-ken, JP;
Kaneo Sugishita, Kanagawa-ken, JP;
Sadao Kurosawa, Kanagawa-ken, JP;
Toshiaki Suzuki, Kanagawa-ken, JP;
Takanori Nakamura, Kanagawa-ken, JP;
Yasuyuki Enomoto, Chiba-ken, JP;
Kaneo Sugishita, Kanagawa-ken, JP;
Sadao Kurosawa, Kanagawa-ken, JP;
Toshiaki Suzuki, 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 cavitations generated on the surface of the blades or reduce the secondary flow around the blades, is provided. A Francis turbine comprises a rotating shaft, a crown, a plurality of blades, and a band. The crown can rotate with the rotating shaft. 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. The rotating shaft, the crown, the blades, and the band as a whole rotate toward a turbine direction during a turbine operation. A projected profile of the trailing edge on a perpendicular plane, which is perpendicular to a center axis of the rotating shaft, is curved toward a direction opposite to the turbine direction at least in the crown side.