The rotating part of a motor is constructed around a shaft. The shaft extends out of the motor in order for objects such as wheels and a fan to be attached to it.
The center of the shaft contains an armature with windings of wire. This wire is looped around an iron core and carries electricity. The many windings strengthens the magnetic field which allows for the rotation motion.
Rotor Com mutator
In order for the rotor windings to carry electricity, they must first receive it by means of a commutator. The rotor commutator is located near one end of the shaft and is comprised of metal segments which make contact with metal brushes. This contact allows for an electric current to travel from the power wires to the rotor windings. While the commutator rotates, the windings change from being connected to a positive terminal to a negative terminal, which causes electricity to flow in opposite directions. Therefore, the magnetic field induced by the flow of electricity also changes between attraction and repulsion.
The rotor brushes are connected to a power source, acting as a passageway for electricity to travel to the rotor commutator. However, this occurs only when the commutator touches against the brushes firmly. Otherwise, electricity will stop flowing. Unfortunately, this leads to the major downside of DC brush motors. The contact between the commutator and the brushes produces friction and heat, which decreases the motor’s speed and efficiency.