Question

What are brushes in an electric motor
Difference between split ring and slip ring
What is commutator

Answer 1

In electric motor the brushes are called commutators and thefunction of commutator in an electric motor is to reverse the direction of current through the coil periodically.

1. The slip ring use for transferring the power from static and rotary part of the machine. And the split ring uses for changing the polarity of the current.
2. The slip ring is used in AC machine, whereas the split ring uses in the DC machine.
3. The slip ring is in the form of the continuous ring, and the split ring splits into two or more parts.
4. The slip ring collects the power from DC generator through the static devices called brushes and then pass the current to the slip ring. The slip ring connects to the coils of the motor. Hence, the power transfer from static to the rotary part of the component. Whereas, the split ring uses for changing the polarity of the current.

Commutation is the process of switching the field in the armature windings to produce constant torque in one direction, and the commutator is a device connected to the armature, which enables this switching of current. The lever arm for the torque produced on the armature varies with the angle of the coil (cos α).