Structural Design Of Magnetic Bearings And Dynamic Analysis Of Its Rotor

Active Magnetic bearings(AMB) have such a lot of advantages that it is called a technology revolution in the bearings. With many advantages, such as contactless, nonfriction, nonabrasion, nonlubrication, nonpollution, long life span, high precision, adjustable damp and stiffness, AMB have more and more wide ranges in application with the development of mechanics, computer, automation control, microelectronics.The principles and the development of AMB, and its application in industries are put forward. The object function and restriction conditions optimum design for AMB's structures are set up. Based on these results, the structural parameter design method of radial and axial AMB is presented, and a test-bed of AMB has been designed by the author. In addition, the principle of a 5 Degrees of Freedom ( DOF ) AMB based on coupled actuators are introduced. The magnetic force's calculation formulae and its structural parameter design formulae are also concluded.The basic theory of using finite element method (FEM) to analyze the rotor's inherent vibration characteristics and three-dimensional FEM are expatiated. By means of ANSYS, the simplified model of the rotor's inherent frequency has been calculated with different environment of rigid and elastic support, and its vibration modals are also simulated.The conception, characteristics, materials, process of Micro Electro-Mechanical System (MEMS) are briefly introduced. The main design method and the application in the AMB of MEMS are studied in detail. Finally, the main problems and the development trend of MEMS are indicated.The developing trend of magnetic bearings in the future is prospected based on the conclusion of the whole article in the end.