基于分形理论的静压支承滑靴系统摩擦自适应特性分析

Friction Adaptive Characteristics of Hydrostatic Bearing Slipper System Based on Fractal Theory

静压支承滑靴副比一般的滑动摩擦副具有更好的摩擦自适应特性,对滑靴的早期磨损有一定的修复效果,但其摩擦自适应机理目前尚不明确。为此,基于分形理论,采用分形维数、尺度系数等分形参数描述滑靴表面形貌,对摩擦自适应过程进行理论分析,开展磨损试验并以分时段更换试件的试验方法观察分形参数的变化情况,得到分形参数对摩擦学特性的影响规律,揭示滑靴摩擦自适应机理。结果表明,滑靴副在发生早期磨损后,分形维数呈增大-减小-再增大-再减小的变化过程,尺度系数和摩擦系数呈减小-增大-再减小-再增大的变化过程,滑靴在早期磨损阶段呈现出显著的摩擦自适应特性,其表面性能表现出劣化-修复-再劣化-再修复的变化特征。

The hydrostatic bearing slipper pair has better friction adaptive characteristics than the general sliding friction pair,and has certain repair effect on the early wear of slipper,but its friction adaptive mechanism is not clear at present.Therefore,fractal parameters such as fractal dimension and scale coefficient are used to describe the surface topography of slipper based on fractal theory,and the friction adaptive process is theoretically analyzed.Wear tests are carried out and the change of fractal parameters is observed by changing specimens in different periods,so as to obtain the influence ruleof fractal parameters on tribological characteristics and reveal the friction adaptive mechanism of slipper.The results show that after the early wear of the slipper pair,the fractal dimension presents a change process of increase-decrease-increase again-decrease again,the scale coefficient and friction coefficient present a change process of decrease-increase-decrease again-increase again,the slipper shows significant friction adaptive characteristics in the early wear stage,and its surface properties show the change characteristics of deterioration-repair-deterioration again-repair again.