Electrical machine and calibrating method for a commutator armature of said electrical machine

The invention relates to an electrical machine and a calibrating method for a commutator armature (10) of said electrical machine. A laminated core (11) is fixedly arranged on the rotor shaft (12) of the commutator armature, said laminated core comprising teeth (20) and grooves (13) distributed alternately on its periphery as well as conductors (14) housed therein. The conductors (14) are fixed inside the grooves by deformation of the material delimiting the groove slots on either of its sides. The aim of the invention is to calibrate the commutator armature (10) while simultaneously fixing the conductors (14) in the grooves (13). To this end, the commutator armature is fixed at the terminal segments (12a, 12b) of the rotor shaft (12). The firstly outward protruding material of the teeth heads (21), located on either side of the groove slots (18), is then deformed from the exterior in a radial direction by means of a calibrating die (19) until a pre-set distance to the central axis (29) of the rotor shaft (12) is attained.