An Experimental Approach to the Study of Rail Wheel/Flange Lubrication
In this study, lubricated flange contact is simulated using various experimental methods as shown in Fig. 1. A full-scale wheel-flange contact simulator consists of rotating real train wheel and static rail specimen which is loaded against wheel flange corner. Only a sliding component of velocity is simulated. When a steel rail specimen is used friction force is measured using a load cell and wear of the specimen is evaluated using an optical profilometer. The specimen can be replaced with a glass one which allows us to determine a lubricant film distribution in the contact. The lubricants used were two bio-degradable greases, one based on rapeseed oil thickened with aluminum and graphite (Grease A) and one based on high-grade esters with solid lubricants (Grease B). Detail information about lubricant film thickness distribution under starved conditions is obtained on optical ball-on-disk contact simulator using thin film colorimetric interferometry. Friction and wear under lubricating conditions is investigated using Mini Traction Machine (MTM – PCS Instruments) with ball-on-disk and pin-on-disk configuration in more detail.