活塞环-缸套液固二相润滑研究

Investigation of Liquid-Solid Two-Phase Lubrication for Piston Ring-Cylinder Liner

基于平均流量模型、微凸体接触模型及颗粒承载模型,引入微米尺度颗粒的粒径、质量浓度、硬度和摩擦副表面形貌参数等,提出了一种液固二相润滑下活塞环-缸套润滑模型。并以此为基础分析了颗粒的承载、摩擦力和二相流体的摩擦功耗。研究表明:由于颗粒的增黏和弹、塑性变形,液固二相润滑剂的承载能力比纯油有所提高;固体颗粒的作用在活塞行程的不同位置是动态变化的;随着颗粒直径、浓度的增加,颗粒分担的负荷和产生的摩擦力、以及二相流体的摩擦功消耗都有所增加;颗粒直径的增加,使颗粒在更广的行程范围承载和产生摩擦力。

Based on the averaged flow model,the asperity contacting model and solid particles carrying model,a theoretical lubrication model for piston ring-cylinder liner with liquid-solid lubricant was proposed.The variables of model include solid particles’ diameter,mass concentration and parameters of rough surface,etc.Using this model,the load and friction force of the particles and the power loss of two-phase lubricant were discussed.The results indicate that the carrying ability of such lubricant will be improved due to the viscosity adding effect and the elastic and/or plastic deformation of particles.Meanwhile,the dynamic effect of particles is presented with the movement of piston.This study showed that with the increase of particles’ diameter or concentration,the particles could endure high loads but increasing the friction force as well as increasing power consuming for the two-phase lubricant.A broadened range for particles to enduring load and producing friction force would be presented at larger diameter.