Attaining High Levels of Bearing Performance with a Nanocomposite Diamond-Like Carbon Coating

Abstract

Mechanical systems that operate in agricultural, construction, and mining and mineral processing applications typically operate in debris-containing and thin-film lubrication environments. Consequently, the lives of rolling element bearings in these applications are often limited by surface fatigue arising from thin-film lubrication, damage from the debris, false brinelling, and scuffing. Traditional approaches utilizing specialized heat treatments and lubricant additives can sometimes delay the onset of early raceway fatigue, but even in these cases the actual bearing life is still usually less than that for which the bearing was designed. Bearings with a highly durable W-aC:H coating applied to the rolling elements are shown to have significantly longer fatigue lives in debris-containing and thin-film lubrication environments and are highly resistant to wear from false brinelling and scuffing.

KEY WORDS:

• Diamond-Like Carbon Coating
• Debris Damage
• False Brinelling
• Fatigue Life
• Nanocomposite
• Rolling Element Bearing
• Scuffing

ACKNOWLEDGEMENTS

The authors thank The Timken Company for supporting this work. Gratitude is extended to J. R. Gnagy, R. D. Evans, R. Fowler, N. Grossi, and C. Hager of the Timken Company; T. Scharf of the University of North Texas; and F. Sadeghi of Purdue University for support of these studies and useful discussions.

Review led by Richard Neu