Development of permanent magnet screw air compressor and its application in various fields

Permanent magnet motor uses permanent magnet to generate the magnetic field of the motor, without excitation coil nor excitation current, high efficiency and simple structure, is a good energy-saving motor, with the advent of high-performance permanent magnet materials and the rapid development of control technology. Permanent magnet motors will become more widely used.

The development history of permanent magnet motor

The development of permanent magnet motor is closely related to the development of permanent magnet materials. China is the first country in the world to discover the magnetic properties of permanent magnetic materials and apply them to practice. More than two thousand years ago, China made the compass by using the magnetic properties of permanent magnetic materials, which played a huge role in navigation, military and other fields and became one of the four great inventions in ancient China.

In the 1820s, a motor appeared in the world is a permanent magnet motor generated by a permanent magnet field. But the permanent magnet material used at that time is natural magnetite ore (Fe3O4), magnetic energy density is very low, with it made of large motor volume, soon replaced by electric excitation motor.

With the rapid development of various motors and the invention of current magnetizer, people have carried out in-depth research on the mechanism, composition and