Analysis of mixed lubrication performance of filtering reducer turning arm bearing

The elastohydrodynamic lubrication (EHL) of filtering reducer turning arm bearing was studied by considering the load, the contact geometry parameters and the real surface roughness. A mixed lubrication model was established to analyze the film thickness ratio, contact load ratio and subsurface von Mises stress of contact zone under rated operating condition and at other speed and temperature. Besides, the effects of groove curvature radius and surface roughness on bearing's lubrication performance were studied either by this model. Results indicated that high speed would improve the lubrication performance by turning mixed lubrication to full-film lubrication. The rise of temperature led to a decrease of lubricant viscosity, deteriorating the lubrication condition and increasing the subsurface von Mises stress. The increase of inner groove curvature radius led to a continuous increase of the subsurface von Mises stress and a first decrease then an increase and again a monotonically decrease trend of film thickness ratio, while the increase of outer groove curvature radius resulted in a continuous increase of the subsurface von Mises stress and a first slight increase and then a steady decrease of the film thickness ratio. Decreasing surface roughness could improve the lubrication conditions, but if the surface was smooth enough, it was not only no use to decrease the surface roughness to reduce dry contact area, but also had a bad effect on subsurface von Mises stress and increased the processing costs greatly.