The Effects of Elastohydrodynamic Traction Behavior on Cage Slip in Roller Bearings

A simple theoretical model of a bearing and measured traction curves are used to explain the different types of experimentally observed cage behavior which result from different lubricants. Traction curves with a pronounced peak are shown to produce unstable cage slip behavior, although bearings can operate steadily in the high slip region. The instability occurred in tests with a high traction fluid but not with ester-type gas turbine lubricants. A bench-top roller bearing rig of the type used in these experiments provides an effective method of assessing the tractive properties of lubricants, using a 25-ml sample.