| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrain an outward flow to the outer peripheral end side from the hub side by centrifugal force when rotating a propeller fan. <P>SOLUTION: The outward flow by the centrifugal force is restrained by a curved surface of these recessed strip parts, the recessed strip part and a projecting part formed between the recessed strip part and itself, by juxtaposing a plurality of curved surface-shaped recessed strip parts extending in the rotational direction in the span direction on the pressure surface side of a blade rear edge part. Thus, a speed component in the radial direction by the centrifugal force on the pressure surface side is pressed to the curved surface of the recessed strip part and a vertical wall surface of a projection strip part outside of the recessed strip part, and the outward flow is effectively restrained. Thus, a flow on the pressure surface side easily flows in the axial direction of the recessed strip part. As a result of it, the flow does not concentrate on the outer peripheral part side of a blade, and a speed difference between the outer peripheral side of the blade and the hub side and an air volume difference are reduced, and while a workload reduces on the outer periphery side, a workload on the hub side increases, and work is finally performed over the whole in the span direction. Thus, air-blowing performance (efficiency and an air-blowing sound) is improved. <P>COPYRIGHT: (C)2009,JPO&INPIT |
