Study On The Fatigue Life Of Bearing Raceway Based On Reinforced Grinding

Bearing has been widely used in the world,its performance directly relates to the service life of equipment.With the development of modern industry and technology,requirements that high reliability,high precision,bearing capacity,dynamic,high speed and high temperature performance and lightweight,miniaturization for bearings are raised higher and higher.Rolling bearing structure is simple,but its design and manufacturing process are very complex.Only master the design principle and its manufacturing process,bearings and associated equipment can meet the needs of people.In this paper,based on high-performance metal materials reinforced grinding machining,the bearing raceway surface is treated by this way,then residual stress is generated,and the generation and distribution of residual stress are studied.And the life test is used to illustrate the effect of this method on the bearing life.The paper first using theoretical analysis,the prediction model of residual stress has been given combined with Hertz contact theory.Metallographic analysis has done for 6 different processing time of samples,the relationship of reinforced grinding time and strength coat thickness has derived.By the SEM analysis,the strength coat thickness has been partitioned,and the Substantive reason that reinforced grinding can produce residual stress has been explained.And then,the finite element simulation for reinforced grinding bearing fatigue life has been done.By using the finite element method,the bearing displacement,equivalent strain,equivalent stress and contact pressure were calculated under a certain load,the effect of residual stress on contact stress,crack and fatigue life of bearing under different radial loads have been analyzed.And compared with the Hertz solution,the results show that the Hertz theory solution is bigger than the simulation solution,with the increase of radial load,the bearing contact stress of outer ring and inner ring also increase,the contact stress of the outer ring is always smaller than the inner ring,fatigue life is bigger than the inner,and the residual stress has little effect on the contact stress of bearings.The residual compressive stress has an inhibitory effect on the growth of the crack.After,it has measured the reinforced grinding residual stress field,and the influence of the stress release is modified by the elastic theory,the distribution of residual stress in depth direction is obtained.The distribution shows that reinforced grinding jet is uniform,and the residual stress increases with the increase of measuring depth.Above 30?m,residual compressive stress attenuates rapidly,and there is no residual stress in the depth of about 120?m,and the residual stress will be changed from compressive stress to tensile stress between 150?m~180?m.The difference between the measured value and the correction value is always less than0.15%,which shows that the effect of stress release can be ignored.Finally,the bearing life test has been carried out,and the variation of bearing temperature,radial clearance,and vibration have been analyzed.