The role of a carbon brush in a motor is to conduct electrical current between stationary wires (stator) and rotating parts (rotor) of the motor. Carbon brushes are typically made from carbon or graphite materials because they are good conductors of electricity and can withstand the friction and heat generated during operation.
When carbon brushes wear out, several things can happen. Firstly, the motor may start to experience electrical problems such as intermittent operation or complete failure to start. This is because worn-out brushes can create poor contact with the commutator or slip rings, leading to unreliable electrical connections. Additionally, increased wear can cause excessive sparking, which may damage the commutator or rotor over time if not replaced promptly.
A carbon brush starter, also known as a starter motor, is used primarily in internal combustion engines to start the engine by turning over the crankshaft until the engine starts running under its own power. This starter motor uses carbon brushes to conduct current to the armature windings, creating the necessary torque to turn the engine over and start it.
A brush motor, or brushed DC motor, operates using carbon brushes and a commutator to switch the direction of current in the motor windings. When current flows through the brushes, it creates a magnetic field that interacts with the permanent magnets or field windings on the rotor, causing it to turn. The commutator reverses the direction of current in the rotor windings at appropriate times to keep the motor running smoothly.
The function of the commutator and carbon brushes in a motor is crucial for converting electrical energy into mechanical energy. The commutator, which is a segmented cylindrical conductor, reverses the direction of current in the rotor windings as it rotates. This reversal of current ensures that the magnetic field generated by the rotor always interacts with the magnetic field produced by the stator in the same direction, thereby maintaining continuous rotation. The carbon brushes maintain electrical contact with the commutator segments, allowing current to flow into the rotor windings without interruption, thereby powering the motor and enabling it to perform mechanical work.