What is a coreless armature rotor?

AIP shares with you the" What is a coreless armature rotor?".

October 25, 2023

What is a coreless armature rotor?

A coreless armature rotor, also known as a coreless armature rotor, is a specialized motor rotor design. This design is unique in that it does not use a traditional iron core to transfer the magnetic field, but instead uses a non-magnetic material such as copper or aluminum to form the armature coils. The concept, advantages, and disadvantages of the coreless armature rotor are described in detail below.

Coreless armature rotor

I. Concept of coreless armature rotor

A coreless armature rotor is a motor rotor design in which no conventional iron core is used to form the magnetic circuit. Instead, it uses non-magnetic materials to form the armature coil. This design gives the motor some unique properties and characteristics.

II. Advantages of coreless armature rotors

High efficiency: Since the coreless armature rotor has no iron core, there is no iron loss or eddy current loss, thus increasing the efficiency of the motor.

High-speed performance: Because of the weight and rotational inertia without an iron core, a coreless armature rotor can reach high speed more easily.

Low-Temperature Rise: Due to the absence of heat conduction from the iron core, the coreless armature rotor has a lower temperature rise, which improves the service life of the motor.

Simple structure: the structure of the coreless armature rotor is relatively simple, and the manufacturing process is also more mature.

Ⅲ.The disadvantages of the coreless armature rotor

High cost: Because the manufacturing process of coreless armature rotors is relatively complex, the manufacturing cost is high.

Reliability problems: in some applications, the reliability of the coreless armature rotor may not be as good as the traditional iron core rotor.

High starting currents: Because of their high starting currents, coreless armature rotors require the use of suitable starting equipment.

Noise Issues: In some applications, coreless armature rotors may produce a high level of noise.


The coreless armature rotor is a motor rotor design with unique properties and characteristics. Its advantages include high efficiency, high-speed performance, low-temperature rise, and simple structure, but it also suffers from high cost, reliability issues, high starting current, and noise. In practical applications, it is necessary to choose the appropriate motor rotor design according to specific needs and scenarios.

AIP coreless armature rotor tester

For more information about the coreless armature rotor tester or another motor tester,  please feel free to contact AIP via Tel/Whatsapp: +86-13969776659, E-mail: international@aipuo.com.