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Brushless DC Motors
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A brushless DC motor, also called a BLDC motor, is a type of electric motor that uses electronically controlled commutation systems. A brushed motor, on the other hand, uses a mechanical commutation system.
In a electric motor system, the motor consists of the commutator shaft, armature or rotor, brushes, and stator. The stator generators the magnetic field around the rotor. The motor can use either permanent magnets or electromagnetic windings to generate a magnetic field when electricity is applied. The rotor is the part of the motor that spins. This also contains electromagnetic windings on each side. When energized, it is magnetically pulled to the opposite magnetic pole on the stator causing it to spin. The magnetic field in the rotor is alternated by the commutator so that it keeps spinning.. A brushed motor has brushes that touch a copper sleeve on the commutator. As it spins, the brushes touch alternating sides sending positive or negative voltage to the windings. In a brushless system is kind of like flipping the brushed motor inside out. The rotor doesn't move, and the permanent magnets rotate.
Advantages of a brushless motor
A brushless DC motor has many advantages since there are no moving parts affecting the electrical connections.
1. The motor experiences less wear and tear as brushes wear out in a brushed motor.
2. Less noise
3. Electrically controlled commutator allows more electromagnets on the stator so the motor is more precise and allows a higher maximum speed.
4. Easier to cool.
5. Smaller and lighter.
This picture compares a 100 watt brushed motor with a 800 watt brushless motor.
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