Dr. Kayri Sharif
Dr. Kayri Sharif holds BSc and MSc degrees in mechanical engineering from the University of Bagdad, where his masters project work introduced him to the field of tribology. He was awarded a PhD by Cardiff University for research in dynamic performance of machine tool spindle bearing systems. He is a member of the IMechE (Institution of Mechanical Engineers) and a chartered engineer. Currently he is a senior research associate at the Cardiff School of Engineering where he is a member of the tribology and contact mechanics research group. Sharif has worked extensively on software development for modelling EHL contacts in machine elements of various kinds, and has authored 37 technical papers addressing issues in tribology and machine dynamics. (Bio last updated 2016-08-01 Contact Randy Stott, Managing Editor, with changes.)
Articles by Kayri Sharif
- Transient EHL Analysis of Helical Gears (August 2016)
This paper addresses the lubrication of helical gears - especially those factors influencing lubricant film thickness and pressure. Contact between gear teeth is protected by the elastohydrodynamic lubrication (EHL) mechanism that occurs between nonconforming contact when pressure is high enough to cause large increases in lubricant viscosity due to the pressure-viscosity effect, and changes of component shape due to elastic deflection. Acting together, these effects lead to oil films that are stiff enough to separate the contacting surfaces and thus prevent significant metal-to-metal contact occurring in a well-designed gear pair.