Research On The Property Of Magnetic Coupling And Test Platform Design

With the development of permanent magnet speed control technology, magnetic coupling plays a more and more important role in modern industry. As the new energy-saving speed control equipment, magnetic coupling is installed between the motor and load. It uses the eddy current generated by the relative motion between the conductor plate and the permanent magnet steel plate. Owing to the eddy current, the induced magnetic field and the permanent magnet magnetic field interacted to realize the torque transfer. Nowadays, the domestic study on magnetic coupling characteristics still has great deficiency, especially in the aspect of performance testing. There is no standard test platform now. The following research has been done based on these facts.Firstly, the magnetic field of the magnetic coupling is analyzed. A mathematical model is established according to the magnetic circuit of magnetic coupling. Then the eddy current loss of copper plate and transmitted torque calculation formula is derived. Next, the influence of designing parameters from every part of magnetic coupling on the transmission torque is calculated and analyzed. Therefore, the structure of magnetic coupling design is optimized.Secondly, the mathematical model of3D motion eddy current field for magnetic coupling is deduced according to Maxwell equations. The simulation model of different magnetic coupling is established and3-D transient magnetic field finite element of the magnetic coupling is analyzed by using the Ansoft software. Through the simulation analysis, the magnetic density distribution, the eddy current density distribution and the eddy current loss density distribution are derived. Meantime, the slip, the air gap distance, copper plate thickness, shape of permanent magnets, permanent magnet thickness and the number of pole pairs on the influence of the eddy current loss and the transmission torque are calculated. Design parameters about every part of magnetic coupling are optimized.Finally, the testing platform about characteristics of the magnetic coupling is designed. Magnetic coupling prototype performance is tested by using experimental platform. Through the slip test and the air gap test, the same calculation result as the simulation model is obtained. And the correctness of the simulation model is verified. It demonstrates that the analysis method is correct and provides reference for optimal design of magnetic coupling.