Internal Structure and Operating Principle of Micro DC Motors

What are the internal structure and operating principle of micro DC motors? Today, WKX, a manufacturer of coreless gear motors, will briefly share some insights:

The coreless motor adopts a rotor without an iron core, also known as a coreless rotor, which represents a breakthrough in the rotor structure compared to traditional motors. The coreless motor is a type of DC permanent magnet servo and control motor, and it can also be classified as a micro motor.

I. Structure of Coreless Motors

The structure of a coreless motor consists of the following components: rear cover, terminals, brush end cover, brushes, commutator, cup-shaped winding (rotor), shaft, washer, sliding bearing, housing, magnet (stator), flange, and positioning ring. The stator is composed of a permanent magnet, housing, and flange. The housing provides a constant magnetic field, resulting in no iron loss in the motor. Without soft magnetic teeth, the generated torque is uniform, enabling smooth operation even at low speeds. At higher speeds, the motor can reduce vibration and noise. The rotor, equipped with windings and a commutator, has the windings connected to the shaft via a commutator plate. The coil moves in the air gap between the magnet and the housing. The commutation system uses a pair of precious metal brushes to minimize brush sparks, which reduces electromagnetic radiation.

II. Principle of Coreless Motors

The coreless motor breaks through the traditional motor rotor structure by adopting a rotor without an iron core, also known as a coreless rotor. This rotor structure completely eliminates power loss caused by eddy currents formed in the iron core. Additionally, the weight and rotational inertia of the micro DC motor are significantly reduced, thereby minimizing mechanical energy loss in the rotor itself. As a result, the coreless motor is classified as a DC, permanent magnet, servo micro-special motor.