Paper XXI(i) Study of the lubricant film in rolling bearings; effects of roughness

This paper reports an experimental and analytical study of the lubricant film formation of deep groove ball bearings and spherical roller bearings under full film and marginal lubrication conditions. A capacitive technique was used for the film thickness measurements; the experimental results were compared to calculations based on the standard EHD formulae. Using this method, it was found that even under what is presently considered as very poor lubrication conditions, full lubricant separation occurred in the rolling element/ring contacts of the test bearings. Furthermore, these separating films were equal to the ones expected from smooth EHD theory. An explanation of this phenomenon can possibly be found in elastic conformity of the asperities in the rough contacts or elastic asperity flattening.