Universal electric motor has elastic piece for moving rotor longitudinally so that friction disc exerts axial pressure

摘要

The universal motor includes brushes (162) for supplying an armature (136) via a commutator (134). A loading device (140,180) produces an internal loading for limiting the rotation speed of the motor in the event of the external load being lower or absent. The loading device includes a friction disc (142) and an elastic piece (186) to move the rotor longitudinally so that the friction discs are subject to an axial pressure.