| 摘要 |
Described is an axial fan in which an impeller ( 1 ) comprises a hub ( 2 ), motor-powered so that it rotates about its own central axis ( 3 ) and a plurality of blades ( 5 ) extending from the hub ( 2 ) in directions transversal to the hub ( 2 ) axis of rotation ( 3 ); the hub having a cup shape and formed by a ring-shaped side wall ( 7 ) and a bottom wall ( 6 ) which has a plurality of long ribs ( 20 ) arranged in a radial direction and extending in height towards the hub ( 2 ) cavity, each of the ribs ( 20 ) abutting on the internal face of the ring-shaped side wall ( 7 ) and delimiting, together with said ring-shaped side wall, a corner area of the bottom wall ( 6 ) positioned in front of the rib ( 20 ) with reference to the hub ( 2 ) direction of rotation (V); each corner area having a through-hole ( 9 ) for discharging any debris, in particular water, sand, soil or sludge, from the hub ( 2 ) cavity to the outside of the hub ( 2 ) The through-holes ( 9 ) are evenly distributed along a circle centered on the hub ( 2 ) axis of rotation ( 3 ) and have a substantially triangular prismatic shape with a vertex wall ( 15 ) facing forwards according to the hub ( 2 ) direction of rotation (V). |
