Apparatus for actuating and controlling the rotation of blades of fans for cooling the coolant in machines/vehicles

A cooling fan (10) assembly for operating machines and/or vehicles, in particular agricultural tractors and off-road vehicles, comprising a fan (10) with at least one blade (20) mounted on a hub (11) which can be rotationally driven about its axis (X-X) by associated driving means (3,3a) suitable for connection to a heat engine (1) of the vehicle and mounted on a fixed support (5) by means of a bearing (3b), and

• an apparatus for actuating and controlling the rotation about its longitudinal axis (Y-Y) of the at least one blade (20), the apparatus comprising:
• a ring (71) provided with a radial seat (71a) inside which a radial pin (72), eccentrically engaged in a base (71) integral with the shank (20a) of the blade (20), is inserted;
• an electric motor (30) which is coaxial with the axis (X-X) of the hub (11) and the shaft (31) of which is coaxially connected to a reduction gear (40), the kinematic output element (143) of which is coaxially connected by means of a screw (51a)/a female thread (76a) coupling to a slider (76) displaceable in both directions along the hub axis (X-X) and kinematically connected to the ring (71) with eccentric pin (72) for driving the base (73) integral with the shank of the blade;
• wherein the reduction gear (40, 140) is a multi-stage epicyclic reduction gear coaxially arranged inside the fixed support (5), and
• the electric motor is coaxially inserted inside the fixed support (5) and fixed thereto.