Study Of The Thin-film Lubrication Based On The Optical Interference Technique

The oil film thicknesses between some precise friction components have been decreased into nanometer level because of the fast development of morden mechanical manufacturing techniques, which makes the friction components working in thin-film lubricating condition. It has great practical significance to guarantee the friction pares’ sufficent lubrication which can help to decrease friction, increase the devices’life span and improve the working liability. For now, the characteristics and the working mechanism study of the thin-film lubrication still needs to be improved.This paper developed an optical interference nanometer-level oil film thickness mesuring device, basing on the relative light intensity principle and the research results of thin film lubrication mechanism. This device, with high resolution ratio, can be used for the thin-film lubrication study of point-contact and pure-sliding friction pares working in low speed and low load conditions. The testing specifications of this device have been studied, which can be considered as a guideline for future researches.The influences of the load, speed, oil viscocity and surface roughness to the oil film thickness in poin contacts thin-film lubrication have been studied using the oil film thickness mesuring device. The results show that the applicative scope of the Hamrock-Dowson formula has some limitations; when the rolling speed is lower and the film thickness is thinner, the experimental film thicknesses are deviated from the film thicknesses given by the Hamrock-Dowson formula; when the rolling speed is higher and the film thickness is thicker, the experimental results are going to be consistent with those given by the H&D formula; the oil film thickness becomes thinner as the load becoming higher; the increasing of rolling speed, oil viscosity and surface roughness makes the oil film thickness becoming thicker; the load and oil viscosity have the influence upon the transition point position where the experimental film thickness becomes to be consistent with the H&D formula, on which the surface roughness has little effect.