Dynamic Behavior Of Magnetic-Liquid Double Suspension Bearing Under Failure Of Hydrostatic Support System

During the long-term operation of magnetic-liquid double suspension bearings,the hydrostatic system of bearing is prone to motor pump shutdown,and the oil circuit is prone to interface leakage and pipeline damage.And the hydrostatic system and electromagnetic system are more likely to accumulate heat under heavy load work for a long time,which makes the temperature of the system of the rise,so that the dynamic viscosity of the hydraulic oil decreases.This will cause the failure of the hydrostatic system,greatly reduce the support strength of the bearing,cause the bearing rotor to be unstable and out of control,drop and collide,and even cause the rotor and stator to wear,crack,crush and other phenomena,greatly affecting the safe operation of the bearing.Therefore,this paper research the influence of bearing key parameters and operating conditions on rotor dynamic behavior under pressure relief failure of bearing hydrostatic system and different oil temperature and experiments were carried out to verify the correctness of the theory.The main research contents of this paper are as follows:(1)The dynamic equation of friction of the bearing of the three-degree-of-freedom system of magneto-liquid double-suspension bearing is established,according to the theory of electromagnetic and hydrostatic.(2)Taking the three-degree-of-freedom bearing system under ideal conditions as the research object,the law of the bearing rotor motion and friction under different structures and operating parameters of the hydrostatic fault bearing were reveled.And concluded that in order to avoid the influence of bearing static pressure failure on the bearing,the parameter design should first consider the parameter design strategy of the hydrostatic fault of the lower unit.(3)The mathematical model of the eccentric rotor of the bearing system is established to reveal the law of the bearing rotor motion and friction under different structures and operating parameters of the hydrostatic fault bearing,and concluded that in order to avoid the influence of bearing static pressure failure on the bearing,the operating conditions should first consider the static pressure failure of the lower unit,and comprehensively consider the design strategy of the static pressure failure of other units.(4)The dimensionless rotordynamic model is used to simulate the bifurcation law of the system with the change of oil viscosity under different main control parameters,and obtain the parameter interval of the rotor system to maintain stable operation,which provides a basis for the parameter optimization and fault diagnosis of bearings.(5)The theoretical simulation was verified by the hydrostatic fault bearing experiment and the compared and analyzed results of the experiment and theoretical simulation.