Method for implementing an electric rotor in existing machines very low speed by installing a multilayer additional crown.

Method for implementing an electric rotor in existing machines very low speed by installing a multilayer additional crown. # The present invention allows the installation of an electric rotor in the existing driven machine, preferably a ball mill, in order to perform the direct with consequent improved performance without risk of the balls mill sticking therein due to magnetic fields drive. # This is achieved by a multilayer additional crown where the layer or closer to drum layers are of material magnetic and outer layer or layers are of magnetic material so that magnetic flux can circulate in the machine.