基于热弹性流体动压润滑的柴油机曲轴主轴承润滑特性分析

基于平均流量模型和Greenwood/Tripp微凸体接触理论,采用有限元法与多体动力学结合的方法,考虑柴油机曲轴主轴承轴颈和轴瓦表面粗糙度、曲轴和轴承座的变形及热效应等影响因素,建立某四缸四冲程柴油机曲轴实体模型和数学模型,分析了曲轴轴承间隙、供油压力和温度、油槽宽度等参数变化时的主轴承润滑特性,并对主轴承进行了优化.最终结果表明,四缸四冲程柴油机第二道和第四道主轴承润滑情况较差,通过增大油槽宽度、减小滑油压力、增大轴承间隙、增加粗糙度等手段可以保证柴油机主轴承最小油膜厚度增加,最大油膜压力减小,实现良好润滑。

Characteristic Analysis of Diesel Engine Main Bearing Lubrication Based on Thermoelastic Hydrodynamic Pressure Lubrication

Based on the average flow model and the Greenwood/Tripp asperity theory, by the combined method of finite element method and multi-body dynamics, the paper calculates the influence factors such as the surface roughness of diesel engine main bearing journal and bearing shell, the deformation of the bearing and bearing block and the thermal effect, i.e. the thermoelastic hydrodynamic pressure lubrication, establishes entity model and mathematical model for a four-cylinder four-stroke diesel engine crankshaft, and analyzes on the main bearing lubrication characteristics. Meanwhile, the paper analyzes the influence of the crankshaft bearing clearance, the oil pressure and temperature, and the groove width on the crankshaft lubrication characteristics. Research results: the minimum oil film thickness of the second and fourth main bearing is relatively small, the maximum film pressure is relatively large, frictionalSpower consumption high; Optimization analysis was carried out on the fourth main bearing, and the effect is obvious by increasing the bearing clearance and widths, reducing the oil supply pressure.