| 摘要 |
A now-noise blower is provided which reduces the turbulence of incoming air flow itself even if there is un-uniformity resulting from circumferential positions around a rotation shaft of air inlet passage. Such a blower includes a blade 1 having its outer circumferential edge 1c warped in a rotational direction and a bellmouth 5 covering the circumference of the blade at the air outlet side, wherein a surface of the bellmouth facing the blade has a convex-shaped first upstream expanding portion 5c upstream extending from a minimum inner diameter portion Pb3 and a concave-shaped second upstream expanding portion 5d further upstream extending, the second upstream expanding portion being continuous from the first upstream expanding portion.
|
