The picture above shows the inner rotor motor
The picture above shows the outer rotor motor
In a nutshell, the difference between the two is the difference between the inside and the outside.
The inner rotor motor rotates together with the main shaft of the rotor motor, the motor base is fixed, the stator is used as the stator, and the inner and the main shaft are used as the rotor .
The outer rotor motor is a rotor that rotates with the motor casing, the motor spindle is fixed, the outer casing is a rotor, and the inner and the main shaft are stators.
The structure is shown below:
The inner rotor generally has a small number of poles, a high speed, and a small torque; the outer rotor generally has a large number of poles, a low speed, and a large torque.
In the case of the same rotor weight, the internal inertia has no large external moment of inertia, so the internal kv is high and the torque is low; the external rotation inertia is large, thereby improving the efficiency and output power of the motor under unstable load.
The internal rotation motor has a small torque and a high rotation speed. Generally, a vehicle model (such as a car model or a ship model) is used, and the motor of the outer rotor has a good heat dissipation.