The Design And Research Of Self-sensing Axial Magnetic Bearing

Compared with ordinary bearings,magnetic bearings have the advantages of no friction,no pollution,long life and so on.Applicable to aerospace and ultra-high-precision machining machine tools,in recent years,it has become the one of the innovative research.Axial magnetic bearing is one of the important parts in the magnetic bearing system,which mainly controls the axial vibration of the rotating shaft,it is very important to the stability of the magnetic bearing system.The paper focused on the basic research of the design,active axial magnetic bearing motion and self-sensing part.Firstly,establish the simplified structure of axial magnetic bearing,deduce the mathematical model of axial electromagnetic force,analysis on the influencing factors of electromagnetic force,and the linearization is carried out,from the angle of dynamic balance,analyze the working principle of the axial balance control,and deduced the axial magnetic bearing stiffness and damping correlation function.According to the vibration during high-speed rotation of the rotor,a new type of axial magnetic bearings is designed.Then study the self-sensing technology,analyze the relationship between the axial displacement of the thrust plate and the current ripple,build up the simulink system model of the axial magnetic bearing.From the analysis of the current ripple of the output signal,in order to separate the current ripple and easy detection,optimize of the system parameters.In order to test the performance of the axial magnetic bearing,in the paper,the power amplifier circuit in the sense of autobiography is loaded by Maxwell Ansoft,simulate the dynamic performance of the thrust plate returned to the equilibrium position under the condition of different switching power frequency,different position and different duty cycle.At the same time,when the rotor is running at a high speed,due to the axial vibration is caused by the external unbalance of the rotor,this paper uses ABAQUS to extract the axial natural frequency,load the axial magnetic bearing and analyze the changes of axial natural frequency,then,the axial natural frequency of the rotor is swept,and analyze the harmonic response.