发动机连杆小头轴承摩擦动力学建模分析及试验验证

The connecting rod small-end bearing is one of the rotating friction parts in the engine with the worst friction condition. The significant coupling effect of bearing deformation, lubrication and frictional heat complicates modelling and numerical solution. Based on the multi-body dynamics and mixed lubrication theory, a coupled tribo-dynamics model of the engine connecting rod small-end bearing is established taking bearing deformation and frictional heat into account. To solve the strong nonlinearity, a numerical solution strategy combining the implicit multistep method is also developed.The wear simulation location is compared with the bench test results to validate the numerical model and solution strategy. After accounting for elastic deformation and thermal effect, the results show the lower surface of the bearing exhibits axial uneven wear and temperature rise. The piston pin's motion is complex, decelerating to a near-stop and then accelerating by friction torque during the compression and working strokes, these phenomena differs from the simplified rigid model. This study is expected to provide an effective tool for assessing the tribo-dynamics and wear behaviour of engine small-end bearings.