Commutator
What is a commutator? The commutator is made of insulated metal segments unlike the solid copper . Electrical brushes (contacts) rub on this rotating ring to make the electrical connection. These segments are wired to act as a rotary switch in order to reverse the electrical current. In a DC motor this switching reverses the magnetic field to keep the motor turning. In a generator the switching changes alternating current into current flowing in one direction (DC).
The commutator including hook type(tang type),slotted type,riser type,shell type,planar type,hook type with reinforced ring,hook type without reinforced ring,slot type with reinforced ring,slot type without reinforced ring.

The materials including copper and compound,and ring,bush,the copper cluding silver copper or electrolytic copper,the compound including phenolic plastic or glass fiber,the ring including glass fiber ring or stee ring,the bush including brass bush or stee bush,or spring bush.