A motor for a cooling fan of a vehicle has a rotor including a driving shaft mounted so as to be rotatable in a stator and a bowl-shaped metal case, having a lateral skirt wall which extends around the stator, and having a bottom wall in which there is constructed a tubular fixing formation through which the shaft extends and which is fixed to the shaft. The tubular fixing formation of the rotor case has an internal diameter which is greater than the diameter of the driving shaft. The motor further has an intermediate insert including a tubular portion which is fixed to the shaft and on which there is fixed the tubular formation of the rotor case, and a transverse connecting portion which extends adjacent to the external surface of the bottom wall of the rotor case, and which is connected or connectable to the impeller.