Abstract:In order to further enhance the performance of the bearing,the mathematical model of fluid lubrication was established with a sliding bearing as the research object.The dynamic characteristic coefficients of bearing was obtained according to pressure perturbation method,and the bearing rotor system instability speed was solved.With the bearing clearance as design variables,the influences of bearing clearance on the minimum oil film thickness,film pressure distribution,dynamic characteristic coefficient and the instability speed were analyzed through the numerical simulation of MATALA.The simulation results show that the minimum oil film thickness will increase with the increasing of bearing clearance and the decreasing of bearing width,and the oil film pressure will decrease with the increasing of bearing clearance.The absolute value of the bearing dynamic coefficients will reduce by increasing the bearing clearance,the rotor instability speed will decrease and the stability of the system will reduce by increasing bearing clearance.