ARP6243 Traction Coefficient Measurement

The lubricant performance capability for aero-propulsion drive systems is derived from the physical properties, chemical properties, and the transport phenomena of the oil. Viscosity, pressure-viscosity coefficient, and elastohydrodynamic (EHD) full-film traction coefficient are inherent properties of the lubricating fluid. Full-film traction coefficient is a required input for thermal performance prediction and engineering design. Traction coefficient data can be modeled and used as an input into bearing and gear analysis codes. This document describes a test method for traction coefficient measurement of 5 cSt oils under service-like conditions for high-stress Hertzian elastic contacting bodies operating under temperatures and sliding (slip) velocities found in high-speed rolling element bearings and gears.