Brushed hub motor
A brushed DC motor uses a configuration of wire coils, known as the armature, as its electromagnetic poles. When the motor operates, the coils and a commutator (a kind of mechanical rotary switch) rotate, while the permanent magnet and brushes remain stationary. The commutator and brushes reverse the current direction in the coils. The changing direction of the current in the coil causes a change in the magnetic pole in the electromagnet and the permanent magnet is pushed around by the electromagnetic force. The contact between the brush and the commutator causes brush wear, and the brushes must be replaced regularly. The replacement is not expensive, but managing the work is not easy.
Brushless hub motor
A brushless motor utilizes a permanent magnet as either its outer rotor or inner rotor. It also uses three-phase drive coils and three hall sensors to track the rotor position. When the sensor tracks the position of the rotor, it sends a reference signal to the controller. Then the controller activates the coils in a structured way, one phase after another.
Brushless hub motors use electronic commutation in which the coils remain stationary, and the poles rotate. As there is no physical contact between any of the components internally, there is almost no possibility of wear, making the motor infinitely durable. These motors require complex controllers and can use three different windings, and each winding is powered separately depending on its position in motion. When the motor passes through a winding, the controller transfers power to another winding so that the motion continues without stopping.
Brushless hub motors are motors without brushes. Their commutators are replaced by electronic servo systems, which use electronic sensors to sense the angle of the rotor. Then, electronic switches control the current through the windings and reverse it. Some motors use only bearings, reducing friction. They are also more durable than their drawn counterparts, but their lifespan is limited only by their size.
Compared to traditional motors, the advantages of brushless hub motors are numerous. They offer higher efficiency, less heat, and better torque per watt. They are more versatile than traditional brushed motors and have different sizes and types to choose from. Because of their light weight, brushless hub motors are suitable for various applications. Some of them are portable, and can be found in ceiling fans and portable fans. They are often touted as being more energy efficient and quieter than most fan models.