车用发动机润滑系统最低润滑油供给量研究

摘要

以某1.8 VVT发动机为研究对象,建立了发动机润滑系统计算模型和轴承动力学模型,对主油道压力、轴承处润滑油流量、轴承轴心轨迹、最小油膜厚度等参数进行了计算分析.通过计算轴承、凸轮和VVT 系统等润滑系统关键部件的润滑油压力需求,获得了润滑系统在不同发动机转速下的最低润滑油压力,该计算结果可为润滑系统设计提供理论依据和边界条件.仿真计算结果表明:发动机润滑系统进油压力对轴承润滑的最小油膜厚度基本没有影响;原润滑系统供给润滑油的液压功率实测值超出理论需求值,最高可达72%,原润滑系统存在发动机中高转速工况下供油过量的问题.%The calculation model of lubrication system and the dynamic model of bearing for 1.8VVT engine were established and the parameters such as main oil channel pressure,lubricant flow at bearing place,axis track of bearing and minimum oil film thickness were calculated and analyzed.Then the minimum lubricating pressure of lubrication system under different engine speeds was acquired by analyzing the lubricating oil pressure demand of the key parts such as bearing,CAM and VVT system and the calculation results could provide theoretical basis and boundary conditions for the design of lubrication system. The simulation results show that the inlet pressure of engine lubrication system has little effect on the minimum oil film thick-ness of bearing lubrication.The measured value of hydraulic power in charge of supplying the lubricant for the original system exceeds the theoretical demand value by up to 72% and so the original lubrication system has the problem of excessive oil sup-ply at high speed.