EXPERIMENTAL APPROACH OF SCUFFING FAILURE IN ANGULAR CONTACT
BALL-BEARINGS

Carmen BUJOREANU¹

cbujorea@mec.tuiasi.ro

Spiridon CRETU¹

spcretu@mec.tuiasi.ro

Daniel NELIAS²

¹ "Gh. Asachi" Technical University of Iasi, ROMANIA

² INSA de Lyon, France

Abstract. The diversity of running-in conditions and, implicitly, of their influences on scuffing failure in rolling bearings contacts limits researcher options to a global investigation. Occasionally, abnormal operation causes premature bearing failure by micro-scuffing and/or scuffing. An experimental study has been performed both on the specimens and full bearings to estimate the scuffing limits in angular contact ball bearings.
Some scuffing tests have been carried out on the high-speed twin-disk machine available at LMC. The specimens were manufactured to allow a simulative tribotesting for scuffing risk. The simulation criteria refer to material, geometric characteristics and lubrication regime of the practical system, which is a 7206 angular ball bearing. High-speed specimen tests were performed to obtain an important ball-inner race contact sliding (>10 m/s) promoting scuffing failure.
Another series of scuffing tests were applied on the 7206 angular contact ball bearing mounted in an original test rig. An electromagnetic brake fixed on the cage assured the cage braking. Owing to this, the ball-inner race sliding speeds was substantially increased and the scuffing appeared.
The accurate choice of simulation criteria leads to establishment of a unique scuffing limit in a given ball bearing for imposed running conditions.
 

Keywords: scuffing, angular ball bearing, experimental investigation, critical temperature