Definition
Gear friction occurs at the interface of lubricated tooth contacts that are subject to combined sliding and rolling motions. Engineered gear tooth surfaces that are not smooth experience diverse lubrication conditions, ranging from full-film to mixed elastohydrodynamic lubrication (EHL) or boundary lubrication conditions, depending on surface and operating conditions and lubricant characteristics. In cases where asperity contacts occur, gear friction is defined by a combination of fluid viscous shear, rolling resistance, and dry friction at the contact interfaces. A fundamental understanding of gear friction is essential as it impacts (1) gear scuffing failures due to excessive heat generation and gear contact fatigue lives and associated failure modes of spalling and micro-pitting, (2) load-dependent (mechanical) gear mesh power losses, and (3) a class of gear vibrations along the direction of the relative sliding and the damping effects along the line of action.
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© 2013 Springer Science+Business Media New York
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Kahraman, A., Li, S. (2013). Friction in Gears. In: Wang, Q.J., Chung, YW. (eds) Encyclopedia of Tribology. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-92897-5_675
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DOI: https://doi.org/10.1007/978-0-387-92897-5_675
Publisher Name: Springer, Boston, MA
Print ISBN: 978-0-387-92896-8
Online ISBN: 978-0-387-92897-5
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