An efficient and accurate calculation of traction in elastohydrodynamic contacts

Traction calculation is an important step in the design and lubrication optimization of machine components with elastohydrodynamic (EHD) contacts. The availability of an accurate and robust method of calculation can be a valuable tool for the machine designer. This paper presents a method of traction calculation that combines the key features of the full numerical approach and previously reported approximation methods. Specifically, the contact pressure and the film thickness are approximated by closed-form expressions while the temperature distribution is numerically calculated using a finite difference method. This scheme of calculation largely eliminates the numerical instability problem that frequently occurs in the full numerical approach while yielding results much more accurate than those obtained by previous approximation methods. The method is robust and allows the use of any rheological models for the lubricant. It is relatively easy to implement on a computer to efficiently calculate traction in both line and point EHD contacts.