摘要 |
<p>The axial flow fan (1; 30) comprises a central hub (3; 33) a plurality of blades (4; 34) which have a root (5; 35), and an end (6; 36). According to one embodiment, the blades (4; 34) are spaced at unequal angles (&thetas;i....,n) which can vary in percentage (&thetas;%) from 0.5% to 10%, compared to the configuration with equal spacing angles (&thetas;=) for fans with an equal number of blades. Preferably, the blades (4; 34) are delimited by a convex edge (7; 37), whose projection onto the rotation plane of the fan is defined by a parabolic segment and a concave edge (8; 38) whose projection onto the rotation plane of the fan is defined by a circular arc. <IMAGE></p> |