What is magnetic coupling?

In the field of mechanical engineering, the coupling is an important part of the mechanical transmission system, known as one of the three major instruments in mechanical transmission, its use is extensive, involving various fields of the mechanical industry, widely used in mining, metallurgy, aviation, military, hydropower, chemical, light textile and transportation industries. The magnetic coupler is a non-contact connection, which can effectively solve the problems of mechanical coupler due to the restoring force and torque generated by axial offset during installation, as well as the vibration generated by radial and angular offset. Thus, in some large torque vibration fields, magnetic couplers have gradually replaced mechanical couplers to transmit torque and power.

magnetic couplings

How does magnetic coupling work?

The magnetic coupling is divided into a copper conductor rotor connected to the input and a permanent magnet rotor connected to the output. The copper conductor generates a magnetic field through the copper coil and interacts with the magnetic field of the permanent magnet on the permanent magnet rotor to transmit power. By adjusting the air gap between the copper conductor rotor and the permanent magnet rotor to adjust the output torque, speed regulation can be achieved. For adjustable speed asynchronous magnetic coupler can also realize the function of soft start and overload protection of the motor, which is widely used in coal, power generation, the chemical industry, and so on.

Magnets used in magnetic couplings

Magnetic couplings need to transmit power, and the main application is the magnetic field strength of the magnetic material, which needs relatively strong magnetic energy. Therefore the magnets on magnetic couplings are usually NdFeB permanent magnet material, or there are some designs where NdFeB is used on the active side permanent magnet disc and SmCo material is used on the driven side permanent magnet disc. This is because SmCo has higher magnetic properties in addition to higher Curie temperature and operating temperature. Magnetic coupling is a non-contact power transmission method, the transmission method mainly relies on the interaction between magnetic fields, temperature stability is another issue to be considered, so magnetic coupling usually uses NdFeB material which has higher magnetic energy, and also uses different grades when considering the actual situation of working temperature.

Applications of magnetic couplings

Magnetic couplings are mainly used to transfer power, the rotation of the motor to the application end. The rotor of the motor will be connected to the input side of the magnetic coupling, and the power is transferred to the output side through the interaction between the magnetic fields of the permanent magnetic material inside the magnetic coupling. Again, because the output end is connected to the application end, the power is thus transferred to the application. We can find this type of magnetic coupling in many applications.

  1. Application on small centrifugal pumps.
  2. Application of pump seals for marine heavy oil mixing units
  3. Foot flange, damping strip, etc. to connect motor and gear pump
  4. Applications on clinical and medical laboratory separation equipment