Multi-field analysis of energy loss and temperature distribution in magnetic couplings

The operation of magnetic couplings produces eddy current losses that lead to heat buildup. Excessive temperatures can demagnetize the couplings, ultimately causing transmission failure. Multi-field coupling was investigated in this study through numerical simulation and modeling methods to study eddy current loss and heat generation issues arising in magnetic coupling operation. The results indicate that the distribution of eddy current loss aligns with the magnetic induction current distribution. Fewer magnetic induction lines pass radially through the isolation sleeve as the magnetic turning angle increases, leading to a decrease in eddy current losses. The isolation sleeve cuts through the highest number of magnetic induction lines when the magnetic turning angle is 0°, resulting in the maximum eddy current loss. As the speed increases, the eddy current loss increases. Eddy current losses lead to temperature variations in couplings. An isolation sleeve forms a high-temperature section between the inner and outer magnets that overlaps with the highest eddy current loss distribution. Temperatures on the isolation sleeve and the inner and outer magnets follow a stratified pattern, with temperatures on the coupling components symmetrically arranged along the circumference. The difference between the eddy current loss P from Maxwell simulations and the cooling water heat transfer Qs from Fluent simulations is 2%. Experimental results show that the measured heat transfer Qe differs by about 9.8% relative to the simulated heat transfer Qs. This margin of error is within an acceptable range, verifying the accuracy of the simulation method.