Study On The Influence Of Misaligned Journal On The Lubrication Performance Of The Journal Bearing

In the process of machining,assembly and using,it can not be guaranteed that the journal axis of the journal bearing is absolutely parallel to that of the bearing.Compared with the parallel journal bearing,the lubrication performance of misaligned journal bearing will be significantly changed.With the increase of titling degree,direct contact with the shaft and bearing may cause dry friction,wear,noise,vibration and impact,bearing pitting,gluing,burning tile etc,which is harmful to the stable and reliable operation of the bearing.Firstly,this paper introduces the basic theory of hydrodynamic lubrication and the related knowledge of the journal bearing,and gives the calculation formula of the lubrication of the sliding bearing.Based on the numerical calculation,the mass conservation boundary condition is used for the analysis of the parallel journal sliding bearing(ideal state).Different eccentric rate,speed,viscosity,oil inlet pressure,cavitation pressure,radius clearance and length diameter ratio on the effects of hydrodynamic lubrication performance is discussed.Secondly,the oil film thickness and the stable working torque expression are derived in the case of the misaligned journal.This paper first analyzes the effects of tilt angle and azimuth on bearing lubrication,and then considers the effects of tilt angle and azimuth on bearing lubrication.The influence of the tilt angle and the tilt azimuth on the lubrication performance of the bearing is compared.The adverse effects of misaligned journal on the stable operation of the bearing are discussed.Finally,the effect of bearing surface defects caused by misalignment journal is studied on the basis of previous research.The influence of circumferential position,shape,area and depth of surface defects on the lubrication performance are analyzed.And we also analyzed the mechanism of these influence.