不同滑滚比条件下脂润滑膜剪切特性试验观察

Experimental observation of shear properties of grease film at different sliding rolling ratios

采用新开发的球-盘点接触油膜装置,对不同滑滚比下的脂润滑膜摩擦系数和膜厚进行了同时测量.试验结果表明,脂润滑膜从富油润滑状态迅速衰减到乏油润滑状态,摩擦系数随着卷吸速度和滑滚比的增加呈现增加趋势.试验发现在较高卷吸速度下存在一个合理的滑滚比,使脂润滑膜在较长时间内具有较高的膜厚和较低的摩擦系数.分析了脂润滑膜演化过程中,富含稠化剂的高黏度润滑膜、残余膜和边界膜所发挥的主要作用.

In this work, the friction coefficient and film thickness of a grease film were simultaneously measured by a new ball-on-disc thin film measurement device at different sliding rolling ratios(SRR). The results showed that the grease films sharply decayed from the fullflooded state to the starvation state. The overall friction coefficient is increased with the entrainment speed and SRR increasing. It was also found that at the higher speeds, there existed a satisfactory SRR, which resulted in a thicker grease film and a lower friction coefficient for a long time. Finally, the main mechanisms of thickener-rich viscosity layer, residual layer, and boundary layer during the grease film evolutions were analyzed.