摘要
A new method combining the slider-crank mechanism dynamic(SCM)and crankpin bearing(CB)lubrication models is proposed to analyze the effects of CB dimensions and engine speed on the lubrication efficiency and friction power loss(LE-FPL)of an engine.The dynamic and lubrication equations are then solved on the basis of the combined model via an algorithm developed in MATLAB.To enhance the reliability of the research results,the experimental data of combustion gas pressure is applied for simulation.The load bearing capacity(or oil film pressure),friction force,friction coefficient,and eccentricity ratio of the CB are selected as objective functions to evaluate the LE-FPL.The effects of engine speed,bearing width,and bearing radius on the LE-FPL are then evaluated.Results show that reductions in engine speed,bearing width,or bearing radius can decrease the FPL but reduce the LE of the engine and vice versa.In particular,the LE-FPL can effectively be improved by slightly reducing the bearing width and bearing radius or maintaining engine speed at 2000 r/min.
提出了一种结合滑块曲柄机构动力学模型(SCM)和曲柄销轴承润滑模型(CB)的新方法,以全面分析CB的尺寸和发动机转速对润滑效率和摩擦功率损失的影响.基于组合模型,利用在MATLAB中开发的算法程序求解动态方程和润滑方程.为了提高研究结果的可靠性,采用燃烧气体压力实验数据进行仿真.选择CB的承载能力(或油膜压力)、摩擦力、摩擦系数和偏心率作为评估LE-FPL的目标函数,分别评估发动机转速、轴承宽度和半径对LE-FPL的影响.研究结果表明,减小角速度、轴承宽度或半径可以减少摩擦功率损失,但会降低发动机的润滑效率,反之亦然.特别地,通过略微减小轴承宽度和半径或将发动机转速保持在2000 r/min,可以有效地改善润滑效率和摩擦功率损失.
基金
The National Key Research and Development Plan(No.2019YFB2006402)
the Key Project of Scientific Research Plan of Hubei Polytechnic University(No.21xjz02A)
the Open Fund Project of Hubei Key Laboratory of Intelligent Transportation Technology and Device,Hubei Polytechnic University(No.2020XY105,2020XZ107).
