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. 20, 2013
Filed:
Jul. 11, 2008
Suguru Nakagawa, Sakai, JP;
Zhiming Zheng, Sakai, JP;
Suguru Nakagawa, Sakai, JP;
Zhiming Zheng, Sakai, JP;
Daikin Industries, Ltd., Osaka, JP;
Abstract
A propeller fan has a gap between a bellmouth and each blade tip. A leakage flow is thus produced from a positive pressure surface of a blade toward a negative pressure surface of the blade via the gap. The leakage flow develops while flowing from the leading edge of each blade toward the trailing edge, thus forming a blade tip vortex. This increases blowing noise and raises the input of the fan motor. In order to suppress the blade tip vortex caused by the leakage flow, the present invention includes recessed portions and projected portions, which are alternately formed in a portion of a blade surface of each blade corresponding to the blade tip.