The Experimental Measurement And Study On Calculation Method Of The Centripetal Force Of Magnetic Bearings

In a whole rotating supported structure, to realize stability rotating of the supported body, the five degrees of freedom except rotation must be restricted, while in a whole mobile supported structure, to realize stability moving of the supported body, the five degrees of freedom except moving must be restricted. But many devices are being developed into small and micro-devices. However, the supported structure and control system of traditional active magnetic bearing of five degrees of freedom are relatively complex, which is not suitable to the micro-devices. This study shows that centripetal effect of magnetic field is used to restrict some degrees of freedom of magnetic suspension system. So the supported structure and control system can be simplified.This study focuses on two objects, which are the magnetic suspension disc system and the speed maglev. Based on experiments of centripetal force, the way of utilizing ANSYS to calculate centripetal force of the magnetic suspension system is discussed. The calculation results by ANSYS match well with the experimental measurement. Through the experiments and ANSYS simulation, there are three conclusions. Firstly, when the supported body is suspending under the offset state, the tangential force which is the centripetal force does exist in the air gap. Secondly, the instability point of the supported body under the horizontal interference can be found, which means the limit offset and anti-interference ability range of supported body can be found. The last but not the least, in order to make better use centripetal effect of magnetic field, there are three key factors in the structural design of magnetic suspension system, which are the number of the electromagnets, the layout the electromagnets and the shape of the armature. The centripetal effect of magnetic field is used to restrict two degrees of freedom in the design of the speed maglev, and the speed maglev suspends stability, which proves that the centripetal effect of magnetic field can be used to restrict some degrees of freedom in order to simplify the magnetic suspension system. There are two meanings in calculating the centripetal force and limits offset of the supported body, one is that the applications area of magnetic bearing in small and micro-devices can be expanded, the other is that the structural design of supporting part of the magnetic suspension system can be optimized, so the control system and the structure of magnetic suspension system devices can be simplified effectively.