| 摘要 |
PURPOSE: A rotating blade of a ventilation fan is provided to prevent air from being forwardly concentrated in a rotary shaft direction, thereby reducing the noise to create agreeable environment where the ventilation fan is installed. CONSTITUTION: In a rotating blade(10) of a ventilation fan1, a pointed end part(12) having a narrow sectional area in the front part of the rotating blade, the sectional area of the blade is increased as it goes to the end part and a concaved dispersion guide curved surface(14) is formed, in which section of the blade is slanted toward the rear than a vertical plane of a rotary shaft(3), so that the radial air flow is generated from the rotary shaft of the ventilation fan.
|
