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:
Aug. 19, 2014
Filed:
Dec. 14, 2010
Chisachi Kato, Tokyo, JP;
Atsushi Yamaguchi, Kanagawa, JP;
Akira Ueda, Kanagawa, JP;
Kazuhiro Nitta, Kanagawa, JP;
Akihiro Otsuka, Sr., Kanagawa, JP;
Tadashi Katsui, Kanagawa, JP;
Masahiro Suzuki, Kanagawa, JP;
Yoshihiko Aizawa, Nagano, JP;
Honami Oosawa, Nagano, JP;
Chisachi Kato, Tokyo, JP;
Atsushi Yamaguchi, Kanagawa, JP;
Akira Ueda, Kanagawa, JP;
Kazuhiro Nitta, Kanagawa, JP;
Akihiro Otsuka, Sr., Kanagawa, JP;
Tadashi Katsui, Kanagawa, JP;
Masahiro Suzuki, Kanagawa, JP;
Yoshihiko Aizawa, Nagano, JP;
Honami Oosawa, Nagano, JP;
The University of Tokyo, Tokyo, JP;
Fujitsu Limited, Kawasaki-Shi, JP;
Sanyo Denki Co., Ltd., Tokyo, JP;
Abstract
A counter-rotating axial flow fan with reduced noise at the target operating point achieved without modifying a front impeller, a rear impeller, or a middle stationary portion is provided. An annular rib including a projecting surface for generating turbulent flow is formed on an inner wall portion of a casing at a position off from the middle stationary portion to a side of the rear impeller, the projecting surface extending radially inwardly of the inner wall portion and extending continuously in the circumferential direction of the inner wall portion. A fluid striking the projecting surface for generating turbulent flow is partially disturbed to form a turbulent flow before entering an area in which the rear impeller is provided. The turbulent flow suppresses flow separation of a fluid flowing along the surfaces of rear blades of the rear impeller from the surfaces of the rear blades.