Method for balancing rotors of electrical machines

A method for balancing a rotor of an electrical machine, the rotor having a shaft with a diameter and at least one laminated core arranged on the shaft, the laminated core having opposite first and second axial ends, the method comprising:

• providing a rotor of an electrical machine,
• providing blanks, each of the blanks having a length that is smaller than an outside diameter of the laminated core of the rotor,
• ascertaining a magnitude and an angular orientation of an initial unbalance at least at a first end of the core of the rotor that is to be balanced, thereby defining an angular position for mounting the blanks on the rotor,
• processing at least a first of the blanks by making a recess in the first blank outside the center of gravity of the first blank, the recess having a diameter matched to the diameter of the shaft and being disposed so that a center of the recess is spaced from the center of gravity of the first blank by a distance depending on the magnitude of the ascertained initial unbalance at the first end of the laminated core,
• mounting the first blank by means of the recess on the shaft at the first end of the laminated core of the rotor that is to be balanced, and
• fixing the processed first blank on the laminated core of the rotor in the angular position.