Study On Performances Of Hybrid Bearing Influenced By Processing Quality And Elastic Deformation

Hybrid lubricated bearing is a new type oil film bearing integrating thecharacteristics of hydrodynamic and hydrostatic bearings and it overcomes theshortcomings of the hydrodynamic and hydrostatic bearings. At present, manyresearches have been conducted, however, the processing quality and elasticdeformation are not taken into account in the researches. Researches indicate that theerrors due to manufacture quality and elastic deformation are close to the oil filmthickness which leads to influence remarkably the properties of the hybrid lubricatedbearing. The research works based on the fundamental theories of the hybrid lubricatedbearing were conducted to study the effect laws of the factors mentioned above to theperformances of the bearing. The researches will contribute to complete the designtheories of the hybrid bearing and provide the theory guides for the manufacture of thehybrid bearing.Firstly, this paper does some researches on the theory of Hydrostatic bearing, andfulfills the relevant theoretical derivation, then discretizes the partial differentialequation by explicit finite difference method, finally figures out the equations that canbe solved through the software MATLAB and solves them.Secondly, it makes the researches on the functions of hybrid bearing withoutconcerning elastic deformation and processing quality including surface roughness,shape error and dimensional tolerance. In the small eccentricity ratio, hydrodynamiceffect is very weak, it does the job required mainly depending on hydrostatic effect. Inthe big eccentricity ratio, hydrodynamic effect is very strong, it satisfies the jobrequirement mainly relying on hydrodynamic effect. In addition, when the bearing bearsdynamic load, its axle center will move everywhere, which helps produce extrusioneffect and enhance wedge effect. To judge the motion of film bearing, it takes stablebearing method to draw the locus of journal bearing.Thirdly, it discusses the performance of oil film bearing on processing quality. Itpoints out that, high surface roughness causes little effect, low surface roughness makeseffects including the variation of load capacity and the minimal film thickness. Initialclearance of oil film bearing has an effect on the load capacity and the minimal filmthickness. Elliptical bearing can enhance the load capacity, especially when the line oftwo focuses and shaft axis are perpendicular. Finally, it discusses the function of oil film bearing on elastic deformation of shaftand bush. It sums up that both the elastic deformation of shaft in the concentrated loadand the deformation of bush in the high oil film pressure can affect the pressuredistribution and film thickness distribution, and the load capacity is below the valuewithout concerning elastic deformation.