Lubrication of Slow Rolling Contacts—The NASA Ball on Plate Tribometer

Abstract

The NASA Ball on Plate Tribometer was built for the investigation of boundary lubricated rolling. Its contact conditions are easily calculated, and can be adjusted to match a range of real hearing applications for stress, surface velocity, pivot, and contact severity. The rig operates under high vacuum at room temperature. Lubricant charge and specimen preparation are well-controlled and well-characterized. Mass spectroscopy instrumentation allows an indication of lubricant degradation during rolling. Other tribological quantities immediately available are contact resistance, friction coefficient, transverse creep, and orbit velocity deficit. Simple specimens allow post-test surface analysis such as FTIR, XPS, microscopy, and profilometry. Here we describe the Tribometer and discuss representative results obtained with liquid, solid, and no lubricant.