to the engine ice the air deflecting blades 26 avoid a build up of heat between the rear side of the tan and the front side of the engine ice by deflecting air radially in the direction of the axis of rotation a a thus heat dissipation is ensured from the radially inner region behind the fan 1 including the rear side the fluid friction coupling 2 and the engine ice fig7 illustrates a few characteristic dimensions such as diameters and angles with respect to the air moving system according to the present invention the parting line 18 does not run exactly parallel to the axis of rotation a a but at an angle u03b4 of approximately 3 4 u00b0 the so called draw the angles u03b1 u03b2 and u03c4 designate the conicity with respect to the axis of rotation a a of the imaginary conical surface defined by the leading edges 11 the extension ring 15 and the conical annulus 8 respectively according to the invention u03b2 gt u03c4 d a is the maximum diameter of the axial blades 7 d ne is the minimum diameter of the axial blades 7 d na is the minimum diameter at the trailing edge of the axial blades 7 d re is the diameter at the leading edge of the nozzle ring 13 and d l is the maximum diameter of the air guiding ring.