Research On Tribology And Wear Of Deep Groove Ball Bearing Under Starved Lubrication

The deep groove ball bearings are widely used in the aviation equipments and aeroengines. In thecase of sufficient lubrication, the deep groove ball bearings have a long life. But in the aero-bearingswith high speed, the phenomenon of starved lubrication often exist, as a result, the life of the deepgroove ball bearings is decreased. Moreover, with the deterioration of degree of starved lubrication,the friction and wear between the bearing components increase rapidly so that the life of the deepgroove ball bearings descreases rapidly. Therefore, it is very necessary and urgent to study the frictionand wear of groove ball bearings under starved lubrication. Some discussions of relative researchsabout this problem were studied in this paper, the method and theory for the analysis of friction andwear of groove ball bearings under starved lubrication were initially established, and that provide abasis for the further study of life prediction of groove ball bearings under starved lubrication.Firstly, base on some basic theory such as the load-carrying dynamics of bearing, Hertz contacttheory and lubrication theory, the calculation method for the oil film thickness of deep groove ballbearings was presented, the calculation method of oil quantity to distinguish the sufficient lubricationand starved lubrication was deduced, and the calculation methods for the friction coefficients of deepgroove ball bearings under sufficient lubrication and starved lubrication were obtained. And then, theinfluence of speed and load on the oil film thickness, and influence of speed, load and geometricparameters of bearing on the dimensionless inlet distance, lubrication oil quantity, and frictioncoefficient for starved lubrication were analyzed. The results show that the oil film thickness anddimensionless inlet distance decrease but the lubrication oil quantity and friction coefficient increasewith the increasing of load, the oil film thickness, dimensionless inlet distance and lubrication oilquantity increase but the friction coefficient decrease with the increasing of speed. And the frictioncoefficient will increase if the phenomenon of starved lubrication become deteriorating.Secondly, the frictional contact problems of the deep groove ball bearings were analyzed byusing the finite element software names as Workbench. The distribution laws of the contact stress,deformation and slip of the deep groove ball bearings were obtained, and the influence of load andfriction coefficient on them were analyzed. The following conclusions can be drawn from the analysisresults. The contact stress, deformation and relative slip of the deep groove ball bearings increase withthe increasing of the load, but the contact stress, deformation and relative slip of the deep groove ballbearings decrease with the increasing of the friction coefficient. Although the friction coefficient of deep groove ball bearings will be increased due to the starved lubrication, but the decreasedmagnitude of the other contact parameters is small, so the Hertz contact theory is also suitable for thefrictional contact analysis of the deep groove ball bearings under starved lubrication.Moreover, the calculation method of wear loss of deep groove ball bearings sufficient lubricationand starved lubrication were studied respectively based on the load-carrying dynamics of bearing. Theinfluence of the speed, load, curvature coefficient, diameter of rolling element and friction coefficienton the slidding velocity, wear distance and wear loss were analyzed. The following conclusions can bedrawn from the analysis results. The effect of the load and curvature coefficient on the sliddingvelocity, wear distance and wear loss are large. The effect of the diameter of rolling element on theslidding velocity, wear distance and wear loss are small. The effect of the speed on the sliddingvelocity is large, but it almost has no effect on the wear distance. The influence of the speed on thewear loss is large under starved-oil lubrication.Finally, to verify the reasonableness of the theoretical analysis of friction and wear for the deepgroove ball bearings under starved lubrication, the friction and wear experiment of the deep grooveball bearings under different degree of starved lubrication was simulated by using the fricton and weartester. The friction coefficient of experimental sample was analyzed by using the data processingsoftware, namely, ORIGIN. The surface morphology of experimental sample after wear was observedby using the3D White light Interferometer, and the wear losses under different degree of lubricationwere obtained. The reasonableness of the theoretical calculation was verified by comparing thefriction coefficient and wear loss of experiment and theoretical analysis.