Patent ID: 6558123
Filing Date: 2003-05-06
Classification: F04D,Y10S

Abstract:
An axial flow fan (1) having a geometrical centre, rotating in a rotation plane (XY) about an axis (2) coinciding with the geometrical centre of the fan (1), the fan (1) including a central hub (3), a plurality of blades (4) each having a root (5) and an end (6), each blade (4) being also delimited by a convex edge (7) and a concave edge (8) and consisting of blade sections with aerodynamic profiles (18), said aerodynamic profiles (18) having a leading edge, a trailing edge and having a blade angle (&bgr;) which decreases gradually and constantly from the root (5) towards the end (6) of the blade (4), the blade angle (&bgr;) being defined as the current angle between the rotation plane (XY) and a straight line joining the leading edge to the trailing edge of the aerodynamic profile (18) of each blade section, the improvement comprising: the projection of the convex edge (7) onto the rotation plane (XY) is defined by a parabolic segment.