Centrifugal blower fan

• US 20040240999A1
• Filed: 04/22/2004
• Published: 12/02/2004
• Est. Priority Date: 04/25/2003
• Status: Active Grant

• Current Assignee: Kioritz Corporation (Yamabiko Corporation)
• Original Assignee: Kioritz Corporation (Yamabiko Corporation)
• Inventors: Kamoshita, Tadashi, Iida, Giichi
• Granted Patent: US 7,086,837 B2
• Time in Patent Office: Days
• US Class Current: 416/179
• CPC Class Codes: F04D 29/281 for fans or blowers
• CPC Class Codes: F04D 29/666 by means of rotor construction or layout, e.g. unequal distribution of blades or vanes

Abstract

It is the object of the present invention to provide a centrifugal blower fan capable of reducing a noise in an operating rotational speed range without degradation in blàwer performance. A centrifugal blower fan comprises a base plate, and a plurality of fan blades arranged on the base plate in a radial pattern to define a plurality of air passages between the pairs of adjacent fan blades, respectively. A portion of the base plate serving as a bottom wall of each of the air passages is formed with a plurality of through-holes.

Claims

1. A centrifugal blower fan comprising:

a base plate; and

a plurality of blades arranged on said base plate in a radial pattern to define a plurality of air passages between the pairs of adjacent blades, respectively, wherein a portion of said base plate, serving as a bottom wall of each of said air passages, is formed with a plurality of through-holes.

2. The centrifugal blower fan as defined in claim 1 , wherein said plurality of through-holes are formed only in the range of approximately one-half the length of a downstream portion of said bottom wall.

3. The centrifugal blower fan as defined in claim 1, wherein the through-hole located at the most downstream portion of said air passage has an inner diameter greater than the inner diameter of a through-hole located upstream of said most downstream through-hole.