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