What is a magnetic rotor？

In various types of motors, fans, pumps, and smart devices, there is an invisible yet crucial component that determines whether the equipment can operate efficiently and smoothly: the magnetic rotor. So, what exactly is a magnetic rotor? What are the main structural types and types of magnets used? Keep reading to find out.

Magnetic rotor is a key component that integrates permanent magnets into its structure; through the interaction of its own magnetic field with the stator windings, it facilitates the conversion of electrical energy into mechanical energy and vice versa. It serves as a core component in permanent magnet motors, brushless DC motors, and various magnetic sensing devices.

Magnetic rotors can be divided into two main categories based on the relative position of the magnets within the motor: internal magnetic rotors and external magnetic rotors. An internal magnetic rotor operates inside the stator. The magnets are bonded to the outer wall of the iron sleeve and rotate around the center of the stator and the entire motor. The greatest advantage of the internal rotor design is its heat dissipation capability. The external rotor, in contrast, operates on the outside relative to the stator. The permanent magnets are bonded to the inner wall of the iron sleeve and rotate around the outer periphery of the stator. The greatest advantage of the external rotor design is its ability to significantly reduce cogging torque.

Sintered hollow neodymium radial rotor magnet

For both inner and outer rotors, common magnet types used in magnetic rotors include sintered arc-shaped neodymium-iron-boron magnets, sintered ring-shaped neodymium magnets, sintered segmented ferrite magnets, and magnetic rings, as well as bonded and injection-molded magnets.

The above provides an overview of magnetic rotors. For example, injection-molded magnetic rotors have slightly lower magnetic performance but offer high toughness and excellent resistance to vibration and impact. Sintered neodymium-iron-boron magnetic rotors, on the other hand, have strong magnetic force and are suitable for high-power-density motors. The choice of magnet type requires a comprehensive evaluation.

Recommendations for some magnetic rotor magnet products;

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