| 摘要 |
PROBLEM TO BE SOLVED: To provide an easily manufacturable centrigugal fan capable of reducing noise and increasing a fan efficiency. SOLUTION: This centrifugal fan 1 comprises a plurality of blades 11 disposed annularly, main plates 7 provided on one end sides of the blades 11, and ring- shaped holding members 13 provided on the other sides of the blades for holding the outer sides of the blades, and is rotated by drivingly rotating means about a rotating axis 10 for blowing. In this case, the blades 11 are formed so that an outside diameter from anoiutside end 21 to a rotating axis 10 on a holding member 13 side is larger than an oiutside diameter dimension from the outside end 21 to the rotating axis 10 on a main plate 7 side, the outside diameter of the blade varies proportionally from the main plate 7 side to the holding member 13 side, and at least the outside end 21 of the blade 11 is formed in curved surface.
|
