Experimental Study Of Repulsive Force Of The Mixed Structure Of Monomer Electromagnet And Permanent Magnet

With the development of semiconductor products, ultra presicion processing platform is urgently desired and its controling method is continuously explored by the people. Althoug the ultra precision processing platform of airflow suspension possesses many advantages, systematic equipment is complicated, stiffness is small, carrying capacity is low and processing precision can merely reach tens of namometers. For the high-precision semiconductor parts, the processing platform of airflow suspension cann't make it at present. This thesis studies the mixed structure of electromagnet and permanent magnet through their properties. This ideal can reach such an effect that the pure electromagnet suspension system can't make it. The permanent magnet plays a predominant role in the hybrid structure. The magnet field comes up when the current flow comes into the coil, which plays an auxiliary role. Therefore, in the case of equal suspension forec produced, the mixed structure requires less current than the pure electromagnetic structure and has greater stability and security. The mixed structure of electromagnet and permanent magnet overcomes the shortcoming of the airflow suspension tech and can even improves the accuracy of the ultra presicion processing of the semiconductor products.In order to determine the main factors affecting the repulsive force and their quantatitive relationship, the theory formula of the calculation of the suspension repulsive force is derived from the calculating principle of the magnetic circuits. After the finite element analysis and simulation of the mixed structure of monomer electromagnet and permanent magnet on a basis of ANSYS, the distribution situation of the magnetic line of force,magnetic current density and magnetic field density can be intuitively observed. On a basis of the orthogonal design of the current flow,suspension spacing,height and diameter of the permanent magnet,turns and height of the coil, the optimal combination of factor order which affects the repulsive force can be found, and provids the basic data in the subsequent experiments. By changing the current, the size of the repulsive force is changed and the suspension spacing is also changed finally, which keeps the suspended matter in a new balance.A linear relation between the change of coil current and the impact of repulsive force can be indicated by analysing the simulation data and test data of single-factor model, the linear relation between the change of coil current and influence of gap of the suspension exists accordingly. The repulsive force of the suspension and its gap aren't changed too much with the change of the coil current, but this fine-tuning effect is required in the controling of the ultra precision processing platform. Thus, this conclusion plays a guding role in the adjusting and controling of the position of the suspended matter in the repulsively suspension.