Modeling and Characterization of Static and Dynamic Electromagnetic Forces of a Non-contact Electromagnetic Loading System

Dynamic loading has always been a challenge of measuring the dynamic performance of high-speed machine tool spindle. Therefore, a specially designed non-contact electromagnetic loading system is developed for measuring the spindle’s dynamic performance in this paper. However, when the spindle runs at a high speed, the eddy current on the surface of rotating body will greatly weaken the dynamic electromagnetic force of loading system, thus this will bring great difficult for exactly predicting dynamic electromagnetic force. Therefore, the dynamic relative permeability is introduced to characterize the influence of eddy current on dynamic electromagnetic force, which greatly simplifies the calculation of dynamic electromagnetic force of rotating body in electromagnetic field. The research results indicate that the dynamic electromagnetic force can be accurately predicted based on the dynamic relative permeability and the error between experimental and calculated values is less than 5%.