PUB - About the change of flow factors during the run-in process of lubricated contacts


As part of the AiF funded project "Optimal running-in" a paper on "Change of flow factors during the run-in of lubricated tribological contacts has been published".The study investigated how flow factors change over the first few minutes of run-in. The work helps to assess the influence of flow factors and provides suitable starting values for tribological simulations.


Hydraulic components, like pumps and motors, consist of several tribological contacts, most of which are lubricated with mineral-based oil. Typically, exposing partners are hard-soft parings, usually nitrated steel against lead-containing brass. After the manufacturing, components go through a run-in process in the first hours of service life. In this work, flow factors, which are a measure of the influence of surface roughness on the pressure build-up, are determined. At close time intervals, optical measurements take place and Flow Factors are
calculated to monitor their behaviour over the first operating hour. The experimental results are finally discussed regarding the influence on the simulation of run-in processes.