Analysis Of Eddy Current And Temperature Field In Double-layer Solid Rotor Asynchronous Magnetic Coupling

The application range of concentric synchronous magnetic couplings was limited by the demagnetization of the magnets in inner rotor in high temperature.The problem of demagnetization in high temperature was solved because magnets were only embedded in outer rotor in double-layer solid-rotor asynchronous magnetic coupling(DAMC),and its application prospect would be great.The transmission performance of DAMC was decreased because of the power loss caused by the high eddy current in the shell and inner rotor,the magnetic property of magnets in the outer rotor would be affected by the heat due to the power loss.The magnetic field,eddy current field and temperature field were analyzed in this paper,the results had guiding significance in the optimize design of the property of DAMC,the controlling of eddy current power loss and the improvement of heat dissipation.The method of boundary equivalent surface current was adopted to derive the formula of magnetic flux density in the shell of DAMC.The finite element analyzing soft ANSYS was used to analyze the length of air gap,the number of magnet poles and the slip rate effect on the magnetic flux density.The analysis results show that the magnetic flux density would be decreased with the length of air gap,the number of magnet poles and the slip rate increased respectively.The formula of eddy current power loss was deduced based on the analysis of magnetic field using basic principle of electromagnetic field.The eddy current field of DAMC was analyzed by ANSYS.Different parameters effect on the eddy current power loss in the shell and inner rotor of DAMC were analyzed.The analysis results show that the eddy current power loss in the shell of DAMC would be decreased with the air gap,slip rate increased respectively and the thickness of the shell,the speed of outer rotor decreased respectively and large resistance material adopted in the shell. The eddy current power loss would be decreased with the air gap increased and the slip rate decreased respectively.The eddy current power loss in the shell and inner rotor of DAMC would be decreased simultaneously when appropriate number of magnet poles was adopted. Solve differential equations of 3D static temperature field was established based on the basic principle of heat conduction.The distribution of temperature in the DAMC was analyzed through ANSYS.The analysis results indicate that the temperature of the shell was highest,and the temperature of the magnets was in the permitted working range.The relationship between the speed of outer rotor,the resistance of the shell and the top temperature of different parts in the DAMC were analyzed by ANSYS.The analysis results demonstrate that the temperature of the shell and the magnets would be effectively decreased with the speed of outer rotor decreased and large resistance material adopted in the shell.