汽油机活塞销轴心轨迹计算及在故障诊断中的应用

采用汉氏法求解雷诺方程，计算出不稳定载荷下滑动轴承在不同偏心率和动力参数和条件下的油膜无量纲承载力，并根据实测的发动机气缸压力计算出活塞销所承受的负荷。然后根据实际负荷与油膜承载力的平衡关系，计算出动载荷下每一时刻的油膜厚度，从而确定活塞销轴心在连杆小头铜套中的运动轨迹。计算结果表明。连杆在整个运行周期中，绝大部分时间承受压缩载荷。且压缩载荷远比拉伸载荷大。此结果可用于发动机活塞连杆组的结构设计与故障诊断中，并能对一些实际故障现象进行合理的理论解释。

The Analysis of The Abnormal Noise of Piston Pin of Automobile Engine

Adopting Hamn's method to solve Reynolds equation,in this paper the dimensionless bearing capacity of the oil film in sliding bearings under unstable load with different eccentricities and kinetic parameters is calculated.Basing on the pressure measured in the engine cylinder,the load of the piston pin is accounted.Then according to the balance relation between the load of the piston pin and the bearing capacity of the oil film,we can decide the moving orbit of the piston pin in the connecting-rod bush by means of the oil film thickness calculated at each moment under the dynamic load.The result shows that the connecting rod is compressed during most running time while the compressed force of connecting rod is much bigger than the pulled force.Making use of the result we could not only design more reasonable structure of piston connecting rod and diagnose the trouble of piston pin more easily,but also explain many practiced phenomena of trouble.