| 摘要 |
<p>PURPOSE: To reduce the quantity of ventilation at high speed revolution and reduce noise by constituting a part of the vane of a ventilation fan out of a flexible member. CONSTITUTION: The inner-diameter side 10a of the vane 10 of a fan is fixed integrally to a main plate 11 and a side plate 12. The outer-diameter side 10b of the vane 10 is constituted of a flexible member such as spring steel, etc., and it is fixed to the inner-diameter side 10a, but this is of such structure that the main plate 11 and the side plate 12 do not contact with each other. The outside diameter of the vane 10 at the time of the fan rotating at a low speed is the same as the time of stoppage, but for the outside diameter 10b of the vane 10 at the time of its rotating at high speed, it curves to the rear in rotational direction by air pressure, etc., and the equivalent outside diameter becomes small, and the quantity of ventilation decreases, and also the effect of noise reduction can be obtained.</p> |
