Motor-driven fan, particularly for a motor vehicle heat exchanger

A motor-driven fan particularly for a motor vehicle heat exchanger, comprising

• a brushless DC electric motor including a rotor and a stator in which the rotor includes a cup-shaped cap with a bottom wall and a cylindrical side wall which extends at least partly around the stator and has a plurality of lateral outflow apertures between said side wall and said bottom wall, said bottom wall having an inner surface and an outer surface, and
• an impeller or fan including a hollow hub from which extends a plurality of main outer fan blades;
• the hub having a front wall fixed to the outer surface of the bottom wall of the cap of the rotor and a lateral skirt which surrounds the side wall of said cap in a radially spaced relationship therewith;
• the hub being further provided with inner ventilation blades acting in operation to generate a flow of cooling air through the motor along a path which extends from one end of the motor opposite the hub of the fan through the stator and towards the bottom wall of the cap within the motor, radially outwardly along the inner surface of the bottom wall of said cap and then through the lateral outflow apertures of the cap of the rotor and into an interspace defined between said cap and the skirt of the hub of the fan and ending outwardly of said hub in a region downstream of the main outer fan blades.