Study On Tribological Characteristics And Numerical Modeling For Space Bearing Under Flooded And Stared EHL

In order to evaluate the lubrication performance of domestic aerospace lubricant, especially the performance of friction behavior and oil film shaping when aerospace lubricant under fully flooded and starved regime EHL, it can only be judged by means of experiment and numerical simulation at present. These assessments have important research significance to improve the quality of design and life of aerospace bearing, even to maintain the normal working of the spacecraft.This paper mainly has studied of lubrication performance of NO. 4129 aerospace lubricating oil. It has analyzed the friction behavior by friction testing, and has used the method of numerical simulation to discussing the oil film shaping.First of all, the multi-grid method that is used in the numerical simulation has been introduced, and it has made the basic equation of point contact under fully flooded and starved EHL dimensionless, and it also has established the defect equations, which provide the bases for programming.Secondly, based on the improvement of original EHL friction testing rig, it has completed the friction tests in different temperature, rolling speed, normal load and slide-to-roll ratio under fully flooded lubrication, and has measured and recorded the testing results. According to the data obtained, new formulae for calculating the traction coefficients when the different working conditions have given under fully flooded lubrication were established, and the change rules of friction coefficient has been analyzed under the different normal loads, rolling speeds and temperatures. Using multi-grid method in processing of numerical calculation, the results of the film thickness and pressure distribution in different working conditions under fully flooded lubrication have been obtained. At the same time, the changes of the film thickness and pressure distribution when the normal load, rolling speed and temperature are varied have been studied. Besides the shear stress distribution corresponding with pressure distribution were calculatedFinally, it also has numerical calculation and friction testing for starved lubrication. Based on the oil-supply layer as the input parameter, the results of pressure distribution, film thickness, the partial lubricant film proportion and the started position of the film thickness in the contact zone have been solved. Moreover, the effect of calculated results has been analyzed when the oil-supply layer has changed. Meanwhile, the change rules of film thickness when normal loads and rolling speed have varied under starved lubrication have acquired. The friction behavior of lubricant under starved lubrication has been expounded according to the friction coefficients which were measured by friction testing rig.The analyses in this paper about the friction behavior and numerical simulation of the lubricant oil could provide some references for the development and application of domestic aerospace lubricant.