考虑润滑油剪切稀化效应的影响，建立了活塞裙部-缸套系统的混合润滑模型，以分析单级和多级润滑油对活塞动力学及活塞裙部润滑性能的影响，并通过实验验证了所建模型的正确性和润滑油的剪切稀化作用.结果表明：多级润滑油具有显著的剪切稀化作用；使用多级润滑油或低黏度的单极润滑油，都可以减小活塞裙部的摩擦损失，但会增大微凸峰接触力以及产生磨损的风险，尤其是在膨胀做功冲程阶段；剪切稀化效应对活塞2阶运动的影响不明显；活塞裙部摩擦损失的预测值与实测值具有较好的一致性.
A mixed lubrication of the piston skirt-liner system is presented, considering the effects of lubricant shear-thinning, to investigate the friction characteristics of the piston skirt for both monograde and multigrade lubricants, and the validity of the model and the effect of the lubricating oil shear-thinning are verified by the experiment. The results show that the multistage lubricating oil has a significant shear-thinning effect, and a decrease in the lubricant viscosity is an effective way to reduce the friction loss of piston skirt, although it may increase the boundary friction, especially at the expansion stroke. The effect of shear-thinning on the piston secondary motion is not obvious, and the measured value of the experiment is in good agreement with the predicted value of the mixed lubrication model.
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