news

Magnetic bearings

Magnetic bearings (MB), also known as magnetic levitation bearings, magnetic bearings, or electromagnetic bearings, suspend objects in a given position without mechanical contact using magnetic force. They offer advantages such as high speed, energy efficiency, low noise, maintenance-free operation, long lifespan, and online controllable and adjustable bearing characteristics. Therefore, they overcome the shortcomings of traditional mechanical bearings, such as short lifespan, need for lubrication, and susceptibility to wear. They are a crucial technological support for achieving my country's "dual-carbon" goals and are of great significance for deepening the transformation of old and new growth drivers, solving "bottleneck" problems, and accelerating the development of new quality productive forces.

 

Magnetic bearings are typical mechatronics products integrating knowledge from multiple disciplines such as electromagnetics, rotor dynamics, sensing technology, and control engineering. Therefore, summarizing and reviewing the development history, research status, and applications of magnetic bearings in related industries is of great significance for promoting technological innovation in magnetic bearings and the development of related industries.

 

Magnetic bearings can be classified in several ways. Based on the type of magnetic force applied, they can be divided into repulsive and attractive types. Based on the number of controlled degrees of freedom, they can be divided into single-degree-of-freedom, two-degree-of-freedom, three-degree-of-freedom, and composite types (four-degree-of-freedom, five-degree-of-freedom). Based on the control method, they can be divided into passive magnetic bearings, active magnetic bearings, and hybrid magnetic bearings. Passive magnetic bearings consist of a permanent magnet rotor and a stator; active magnetic bearings consist of a rotor, electromagnets, sensors, a controller, and a power amplifier; hybrid magnetic bearings use permanent magnets to generate magnetic force to balance the rotor's gravity, and electromagnets to generate electromagnetic force to balance external dynamic loads.

 

Active Magnetic Bearings: Active magnetic bearings generate controllable electromagnetic force through electromagnet coils, suspending the rotor and maintaining its operating state.

Hybrid Magnetic Bearings: Hybrid magnetic bearings, also known as permanent magnet biased magnetic bearings, have a mechanical structure including a stator, biased permanent magnets, control coils, and a rotor.

 

Industrial Applications of Magnetic Bearings: With the continuous advancement and development of magnetic bearing technology, the performance of magnetic bearings is constantly improving. Through continuous research, magnetic bearings now have numerous mature products in various fields, including high-speed motors, energy storage flywheels, high-speed spindles, artificial heart pumps, compressors, and eddy current molecular pumps.