An established Hybrid technique has been extended to study lubricant film in EHL conjunctions using ultra thin film interferometry i.e. the spacer layer method. The Hybrid technique combines experimental study with advanced numerical calculations including a fast algorithm for evaluation of pressure distribution. Image analysis is employed to evaluate a 3-D film thickness map from a colour interferogram. The map is then used for calculating pressure distribution by solving the film thickness equation. The general theory of stresses and displacements in a two-layer system is applied in the present work to a circular point contact of an elastic layer firmly bonded to an elastic substrate. The numerical formulation was employed for computing pressure distribution in the EHL contact from the measured elastic deformations and correction of measured film thickness. The dynamic and static results are presented and discussed. A simple tool to estimate the compression of elastic layer based on calculations of static dry contact is suggested. The calculations were performed for sapphire discs with silica and diamond-like coatings.
Godkänd; 2001; 20080508 (cira)