Brushless motors operate in different ways, and can be divided into inner rotor brushless motors and outer rotor brushless motors. The inner rotors are all three-phase and are more expensive. The outer rotor is usually single-phase, the price is affordable, and the mass production is close to the carbon brush motor, so it has been widely used in recent years. The price of the three-phase outer rotor is close to the price of the inner rotor. The disadvantage of a brushed motor is the advantage of a brushless motor. It has the advantages of high efficiency, low energy consumption, low noise, long life, high reliability, servo control, stepless frequency conversion speed regulation (up to high speed), etc. It is much smaller than the brushed DC motor. The control is simpler than the asynchronous AC motor, and the starting torque is large and the overload capacity is strong.