Influence of Sliding Speed on Boundary Lubrication

Bifurcations from steady sliding to stick slip in boundary lubrication

We explore the nature of the transitions between stick slip and steady sliding in models for boundary lubrication introduced in J. M. Carlson and A. A. Batista, Phys. Rev. E 53, 4153 ~1996!. The models are based on the rate and state approach which has been very successful in characterizing the behavior of dry interfaces @A. Ruina, J. Geophys. Res. 88, 10 359 ~1983!#. Our models capture the key...

The influence of tem perature on boundary lubrication

The frictional behaviour between mild steel surfaces lubricated with excess of pure hydro­ carbons, ketones, alcohols, amides, acids and esters has been investigated at low speeds and under high loads. In all cases a transition from smooth sliding to irregular stick and slip motion takes place at a temperature characteristic of the lubricant employed. Experiments in which lubricant films one or...

Hydrodynamic Lubrication of Sliding Vanes

Dependence of boundary lubrication on the misfit angle between the sliding surfaces.

Using molecular dynamics based on Langevin equations with a coordinate- and velocity-dependent damping coefficient, we study the frictional properties of a thin layer of "soft" lubricant (where the interaction within the lubricant is weaker than the lubricant-substrate interaction) confined between two solids. At low driving velocities the system demonstrates stick-slip motion. The lubricant ma...

Lubrication of Sliding Bearings for Hydropower Applications

The influence of pad facing material on hydrodynamic lubrication in tilting-pad thrustbearings is investigated in terms of pad and oil-film temperatures and oil-film thickness. Two tilting-pad thrust bearings are examined: one with babbitt pad facing, the other with a layer of a PTFE based composite material. Frictional torque, pad, collar and oil-film temperatures and oil-film thicknes...