Research On Mechanical P Roperty And Crown Optimization Of Cylindrical Roller Bearing Under Misaligned Load Condition

The cylindrical roller bearing is widely used in heavy-duty mechanical system due to its large carrying capacity and convenient installation.Since this type of bearing does not have the self-aligning function,the misalignment of the bearing during the assembly process and the overturning moment in the service environment will cause it to work under the misaligned load condition.On the one hand,the misaligned load of the cylindrical roller bearing causes excessive wear on the heavy-load end of the roller,which causes early failure,and greatly shortens the service life of the bearing.On the other hand,it changes the bearing stiffness and affects the vibration behavior of the bearing.At present,although some research has been done on the cylindrical roller bearing under the misaligned load condition,there are still many challenges in analyzing the stiffness characteristics of the bearingand optimizing the roller crown under the misaligned load.Therefore,the research on the mechanical properties and crown optimization of cylindrical roller bearing under misaligned load condition has important engineering application value.In this study,the cylindrical roller bearing is taken as the research object,and the effects of load and shape modification on the mechanical properties and fatigue life of the bearing under the misaligned load condition are studied.The main research contents are as follows:(1)Considering the shape modification of the roller,the contact mechanics analytical model of the cylindrical roller bearing under the misaligned load is established based on the slicing method and the influence coefficient method.The validity of the model is verified by the finite element method,and the influence of the misaligned load on the contact performance of the bearing is analyzed.(2)Based on the slicing theory of roller and raceway,comprehensively considering the contact stiffness and oil film stiffness of roller and raceway,the stiffness calculation model of bearing under misaligned load is established by using stiffness string and parallel formula.The model is verified by the finite element model.The effects of misaligned load,rotation speed and clearance on bearing stiffness are studied.(3)Based on the stiffness identification method of cylindrical roller bearings under misaligned load,a test bench that can simulate the bearing misaligned load condition is designed and built to test the bearing stiffness under different working condition.The effects of parameters such as load,speed and misaligned load on bearing stiffness are obtained.(4)According to the traditional shape-modification design method of roller and the stress distribution characteristics of the bearing during the misaligned load,a modified method combining asymmetry and exponential crown is proposed,which effectively reduces the stress concentration phenomenon of bearings under misaligned load,and improves the service life of bearing.Finally,taking the maximum life of the bearing as the goal of optimization,the genetic algorithm is used to optimize the shaping parameters of the exponential crown.Through the research above,the contact mechanics performance of cylindrical roller bearing under the misaligned load is completed.The calculation method of stiffness under bearing misaligned load is proposed.The stiffness test bench for simulating bearing misaligned load is developed.The influences of misaligned load on bearing contact performance,stiffness characteristics and fatigue life are clarified.The optimized design of the roller crown is realized.The results of this paper provide theoretical support arid technical reference for the structural design of cylindrical roller bearings subjected to misaligned load.