An axial fan includes a motor, an impeller and a hub of the impeller for connecting to a shaft of the motor. A bottom wall of the hub has a central portion and an outer annular portion connected to the central portion by an intermediate portion defined by a plurality of blades arranged radially and angularly distributed about an axis of rotation. The blades are elasto-plastic blades and are able to prevent the impeller from moving axially parallel to the axis, moving radially perpendicular to the axis and a bending of the impeller with movements normal to the plane in which the mean surface of the impeller itself lies. The blades allow a movement with torsional bending around the axis to allow the damping of the resonance frequencies of the assembly formed by the impeller-shaft-rotor.