US Patent 7696663 Rotor for a forced-air-cooled electric motor

A rotor (2) for a forced-air-cooled electric motor, in particular a universal motor, especially for use with electrical power tools, has a laminated armature (6) incorporating longitudinal slots (8) and with wire windings of a coil (10) protruding from the longitudinal slots (8) on the front face where the windings form coil connecting heads (20, 22). Some or all of the longitudinal slots (8) in the laminated armature (6) contain a rod (28) aligned in the longitudinal direction and protruding axially from one or both front faces (24, 26) of the laminated armature (6), whereby the protruding rod ends thus surround the coil connecting heads (20, 22) on the respective front face to protect the coil connecting heads from abrasive wear.