Study On The Energy Loss Of Magnetic Levitated Rotor

Magnetic bearing is a special form of the bearing which makes its rotor suspend in space using a controllable electromagnetic force.Because of its many unique characteristics, such as un-contact, no abrasion, lubrication free, long lifetime, fitting for high speed and controllable, etc. the magnetic bearing has a wide application in many areas. The magnetic levitated rotor eliminates mechanical friction when it rotates with high speed, but due to eddy loss, hysteresis loss and windage loss of magnetic levitated rotor, there is still a equivalent friction force which is similar with the mechanical friction force. So it has important realistic meaning and theoretical value that the energy loss of the magnetic levitated rotor is researched. Its main research work are as follows:Firstly, the energy loss of the magnetic bearing is systematically classified,and the formulas of eddy loss,alternating hysteresis loss and rotational hysteresis loss of the radial and axial magnetic bearing is derived. Secondly, in order to make the research more universal meaning, the paper makes the magnetic bearing simply into the minimum unit, U-type electromagnet, and it makes the magnetic experimental system simply into the two degrees of freedom of magnetic bearing apparatus in the research. The energy loss of magnetic levitated rotor during the low speed movement is calculated with the analytic method and measurement method. And the following conclusion is obtained:When the speed of the moving object is less than0.7m/s, more than90%of the energy loss comes from the hysteresis loss of two U-type electromagnet. Lastly, the energy loss of the five degrees of freedom of magnetic levitated rotor is calculated with the analytic method and measurement method,which indicated that the more high speed the rotor runs in,the more loss is caused by eddy loss and windage loss, the less loss is caused by hysteresis loss in the total loss as well.