柴油机曲轴润滑与弯曲振动耦合影响研究

为研究柴油机强化过程中曲轴的弯曲振动和润滑性能的耦合关系,基于曲轴动力学和润滑理论,考虑曲轴和轴承座的弹性变形,建立某型12缸柴油机曲轴计算模型,分析主轴颈弯曲振动和最小油膜厚度间的耦合关系,并研究轴承宽度、半径间隙和润滑油黏度对两者的影响。结果表明:最小油膜厚度与弯曲振动变化趋势相反,两者存在耦合关系,同时油膜能够对振动起到一定的缓冲作用;在研究范围内,最小油膜厚度随主轴承宽度和润滑油黏度的增加而增加,弯曲振动随之减小;半径间隙对润滑和振动的影响较大,适当增大间隙值,最小油膜厚度增加,过大的间隙值加大轴颈的振动冲击,降低最小油膜厚度。该结果对柴油机强化设计过程中曲轴的润滑与振动预测和控制提供了参考。

Study on Coupling Effect of Crankshaft Lubrication and Bending Vibration in Diesel Engine

In order to study the coupling effect of bending vibration and lubrication for diesel engine crankshaft in the process of strengthening,based on crankshaft dynamics and lubrication theory,considering the elastic deformation of the crankshaft and bearing,the calculation model of 12 cylinder diesel engine crankshaft was built.The coupling relationship between main shaft neck bending vibration and the minimal oil film thickness was analyzed,and the effects of bearing width,radius of main bearing clearance and the oil viscosity.The results show that there is a coupling relationship between bending vibration and the minimal oil film thickness,the minimum oil film thickness is opposite to the bending vibration,and the oil film can buffer the vibration.Within the research range,the oil film thickness is increased with the increase of the main bearing width and oil viscosity,and the bending vibration is decreased accordingly.The radius clearance of the main bearing has a great influence on lubrication and vibration,and the oil film thickness will increase when the clearance value is appropriately increased.However,while the clearance value is too large,the vibration impact of the shaft neck will increase and the minimum oil film thickness will decrease.The research results provide a reference for the prediction and control of crankshaft lubrication and vibration in the process of diesel engine strengthening design.