In a brushless motor, there are no carbon brushes, which is the opposite of a brushed motor. Therefore, the magnets in a brushless motor form the rotor.
In brushless motors, especially those in the model field, almost 100% use neodymium - iron - boron strong magnets. This is mainly because neodymium - iron - boron magnets have strong magnetic force, and the power of the motor is closely related to the performance of the magnets. The volume and grade of the neodymium magnets determine the maximum power of the motor.
As we all know, ferrite has low performance. The low performance leads to low motor power, so it is rarely used.
Brushless motors usually use sintered neodymium - iron - boron (magnetic tiles) and bonded neodymium - iron - boron (ring - shaped) materials more often. When magnetic tiles are used as the stator of a brushless motor, there are usually more than 6 poles. But when magnetic tiles are used as the rotor of a brushless motor, there can be 4, 6 or more poles.
The magnetic ring of a brushless motor usually has a diameter greater than 20, the number of magnetized poles is between 4 - 12, and its wall thickness is mostly between 1.5 - 5.0.
