Simulation analysis of wear characteristics of connecting rod bearing bush based on improved mixed lubrication model

The failure rate of crankpin bearing bush of diesel engine under complex working conditions such as high temperature, dynamic load and variable speed is high. After serious wear, it is easy to deteriorate the stress state of connecting rod body and connecting rod bolt, resulting in serious accidents such as connecting rod fracture and body damage. Based on the mixed lubrication characteristics of connecting rod big endbearing shell of diesel engine under high explosion pressure impact load, an improved mixed lubrication mechanism model is established, which considers the influence of viscoelastic micro deformation of bearing bush material, integrates the full film lubrication model and dry friction model, couples dynamic equation of connecting rod. Then the actual lubrication state of big end bearing shell is simulated numerically. Further, the correctness of the theoretical research results is verified by fault simulation experiments. The results show that the high-frequency impact signal with fixed angle domain characteristics will be generated after the serious wear of bearing bush and the deterioration of lubrication state. The fault feature capture and alarm can be realized through the condition monitoring system, which can be applied to the fault monitoring of connecting rod bearing bush of diesel engine in the future.