Numerical Study on Load Carrying Mechanism of Two Parallel Lubricated Rough Surfaces With Relative Motion

In the present paper, the load carrying mechanism of two parallel lubricated rough surfaces with relative motion is numerically analyzed from the microscopic view. It is found that each asperity of the surface forms mini-type convergent and divergent wedge sliders. The convergent wedge can create positive hydrodynamic pressure and forms a hydrodynamic lubrication film so that pressure is produced to bear an outside load. The Reynolds equation is used to analyze the influence of the roughness on the performances such as the pressure distribution, the load carrying capacity, the shearing force, the friction force and etc. The varying rules of the load carrying capacity and friction coefficient with the peak height of roughness are discussed in detail, and the influence of the minimum film thickness on lubrication state is also analyzed. The results indicate that under a given lubrication film thickness the load carrying capacity can achieve the maximum value and then decrease slowly with the peak height increasing, while the friction coefficient can achieve the minimum value. Furthermore, under the given condition of the peak height and 1 μm⩽h₀⩽100 μm of the minimum film thickness the load carrying capacity drops down gradually, while the friction coefficient increases gradually with increase of the minimum film thickness.