The Design And Reseach On The Transmission Characteristics Of Electromagnetic Induction Magnet Coupling

With the progress of science and technology,the making of magnetic couplings develops rapidly.What's more,the couplings,application also keeps covering an increasing range,especially in fields of mining,paper-making,petrochemical,pneumatic drive and hazardous medium drive.Advantages such as simple structure,slight vibration,low friction and static seal make magnetic couplings replace traditional mechanical couplings gradually.Based on traditional single air-gap disc magnetic couplings and by the principle of electromagnetic induction,a new type of induction magnetic couplings with double air-gaps and solid layers are designed in this paper.On the one hand,the new-type couplings can decrease the axial force of traditional couplings.On the other hand,the couplings can further improve the transmission performance on the basis of general magnetic couplings with solid rotors.According to the basic principle of magnetic circuit,the circuits of induction magnetic couplings are designed firstly,and then the main circuits of them are analyzed.In the paper,the air-gap magnetic fields of magnetic couplings are analyzed by analytical method.Under certain assumptions,solution models are made in a static magnetic field.Analytic expressions of permanent magnets' magnetic flux density in each part of couplings are deduced from the models.The thickness of inner rotors' outer layers is an important performance parameter of the magnetic couplings with double-layer solid rotors,and it is one of the vital factors influencing the couplings' torque performance.A multilayer theoretical analysis method is adopted to construct calculation models for the thickness of outer rotors in the couplings.For an accurate research on transmission performance of the couplings,a numerical analysis towards the magnetic field is carried out by using the software Maxwell.Performance characteristics of induction magnetic couplings are deduced from the theoretical formulas and the analysis results.Influences of structural parameters on the transmission performance of the couplings are also analyzed.Besides,the distribution of the couplings' internal eddy current field is analyzed by ANSYS Maxwell software.And influences of structural parameters on the distribution of inner rotors' eddy currents are obtained from the analysis,which further optimize parameters of the couplings.Based on the basic principle of thermal conduction,a 3D finite element model of the couplings' temperature field is constructed by ANSYS Workbench,and then the temperature distribution of the couplings is obtained.The results show that the highest temperature of permanent magnets appears on the inner surface of the couplings,i.e.,the side near air-gaps,and the operating temperature of the magnets is within the allowable range.