Study On Dynamic Characteristics Of Tapered Bearing With Lubrication Effect

A tapered roller bearing is the important mechanical transmission component.In the past years,elastohydrodynamic lubrication and dynamic models of this type of bearing have been established to analyze the bearing performance.Most of these dynamic model do not consider the effect of oil film stiffness and damping,as a result,there are few reports on the coupling analysis of lubrication and dynamics.In order to overcome the difficulty of coupling study of lubrication and dynamics for tapered roller bearings and provide a reference for accurate analysis of the dynamic performance of tapered roller bearings after considering lubrication,this paper establishes a dynamic model of tapered roller bearings considering lubrication,with support of the National Key R&D Program of China(No.2018YFB2000604)and the National Natural Science Foundation of China(No.51775067).Then according to the model,the dynamic characteristics of tapered roller bearings are studied.Meanwhile,the relevant simulation software of tapered roller bearing is developed.At the present,the software has been initially applied to the analysis of CRRC’s bearings.After that,based on the simulation results of the software,the fatigue life is discussed,which provides a reference for the use and design of tapered roller bearings.First of all,this paper takes into account the dynamic changes of oil film stiffness and damping,and establishes a lubrication and dynamic coupling model for tapered roller bearings.To this end,the dynamic coupling equations are solved with the backward difference method(BDF)and Newton-raphson iterative algorithm in this paper.Then the calculation results are compared with experiment values in associated literatures to verify the correctness of the model.Compared with the previous bearing dynamic equations,proposed dynamic equations can overcome the disadvantage of without considering the real-time variation of oil film stiffness and oil film damping.Therefore,proposed equations are more accurately to analyze the dynamic characteristics of tapered roller bearings.Secondly,this paper takes the tapered bearing 33112 as an example to deeply study the influence of lubrication parameters,working condition parameters and structure parameters on its dynamic characteristics.To this end,the developed Fortran program is embedded into Adams software for bearing simulation analysis,and the correctness of simulation results is verified by it’s comparison with the experiment results.The comparison shows that the bearing vibration is less obvious with the lubrication effect.Furthermore,reasonable design of the rib inclination angles and the roller end spherical radius can effectively suppress the vibration level of the inner ring,and at the same time increase the minimum oil film thickness between the roller and raceway.Then,the dynamic simulation software of tapered roller bearing is developed.The software is based on the joint programming of Fortran and ADAMS.Users can apply the software to perform parametric modeling of bearings,which greatly reduces the time to build bearing models.At the same time,the dynamic characteristics of the bearing can be simulated through setting process parameters and lubrication parameters,and the calculation results of bearing dynamics,oil film thickness,oil film damping,and oil film stiffness can be given.In general,the developed software provides a simulation platform for the structural design and dynamic characteristics analysis of the tapered roller bearing.Finally,based on the calculation results of the developed dynamics simulation software,the fatigue life of the tapered roller bearing is analyzed.To this end,the bearing dynamics simulation results and the bearing stress distribution cloud diagram are used,and the fatigue life is solved by n Code Design life software.The simulation shows that the fatigue life of tapered roller bearings with lubrication effect is much higher than that without lubrication effect.In addition,the inner ring fatigue life of tapered roller bearing is the shortest and the inner ring is more likely to be damaged during work.