| 摘要 |
PROBLEM TO BE SOLVED: To provide a centrifugal fan emitting low noise and having a high hydrostatic pressure performance and also an air-conditioner equipped with such a fan. SOLUTION: The centrifugal fan is structured so that vanes 4 are installed at a certain spacing between a hub 2 and a shroud 3, wherein the leading edge 4a of each vane 4 has such a shape as furnished with a stepped surface 13 and in discontinuity in the vane width direction, and the stepped surface 13 is made of a slope having a certain inclining angle relative to a plane perpendicular to the rotational axis. According to this constitution, the air flow directed to the leading edge 4a of each vane 4 is disturbed by collision wit the discontinued portion so that a vertical vortex 21 is generated. The vertical vortex 21 guided to the stepped surface 13 is produced concentrically on either the outer surface 4e or inner surface 4f of the vane 4 to make a further growth and has a large, vigorous energy, so that exfoliation at the outer surface 4e or inner surface 4f is suppressed by this vortex 21 effectively, and the blowing noise is reduced certainly. |
