Analysis of Hybrid Magnetic Bearing for High Speed Spindle

High speed, precision, ultra-precise machining technology is an important trend of advanced manufacturing Engineering. The high-speed motorized spindle enable to attaining greater complexity and accuracy, which demands rotating machinery to be run at high speeds. Non contacting magnetic bearing are suitable for supporting the spindle and rotor in the rotating machinery because of the high temperatures generated by the contact between the spindle and bearing. The basics of Active Magnetic Bearing technology, material selection and working of hybrid active magnetic bearing of high speed spindle are well described. The analytical derivation of the forces in a Hybrid magnetic bearing is described and the initial parameter design is done with magnetic circuit. From the initial parameter the permanent magnet is designed through FEA using ANSYS workbench. Finally, simulation of the designed magnetic bearing for magnetic flux density and force dependency of current coil and rotor position are done. From the prediction of current stiffness and position stiffness we found that current stiffness provide more linearity than position stiffness.