Commutator wear due to drawn arcs

As commutator motors are still widely used in several consumer appliances and electric drives, it is worth to develop same general methods making their most vulnerable parts, that are mechanic commutators, more endurable due to commutation and switching phenomena accompanying their operation. Since the commutator optimization due to electrically caused wear, introduced in ICEM 2010, dealt manly with short arcs, present paper discusses drawn arcs and electric discharging arc between brushes and commutator bars at the instant of their physical separation.