Research On Residual Stress Analysis Of Power Spinning Sliding Bearing Based On ABAQUS

The sliding bearing is a very important component in the structure of the diesel engine,which is connected with the piston pin and the small end of the connecting rod.It is subjected to the alternating explosive force of the cylinder and the inertial force of the connecting rod during operation,and it is also affected by the thermal load generated by the reciprocating motion of the piston.Therefore the sliding bearing is in the extremely harsh working environment of high temperature and high pressure.The quality of sliding bearings directly affects the quality and service life of diesel engines,and has always been valued by developers and manufacturers of diesel engines.At present,the sliding bearing is mainly formed by power spinning,but the plastic deformation of the metal material and the unevenness of the material flow during the spinning process will generate residual stress both inside and outside.The existence of residual stress will seriously affect the dimensional accuracy,shape tolerance and hardness of the sliding bearing.The selection of technological parameters has a great influence on the residual stress.Therefore,the research of the forming process,distribution law and the influence of technological parameters on the residual stress is great significance to the actual production of sliding bearings.In this paper,the sliding bearing of tin bronze(QSn7-0.2)material in a certain type of diesel engine is taken as the research object.Based on the ABAQUS finite element simulation software,the forming process of the sliding bearing in the power spinning process is studied,and the residual stress is obtained in the axial direction,and the distribution law is discovered in the direction of wall thickness;and the influence of different levels of technological parameters on residual stress wall thickness distribution is studied such as thinning rate,feed ratio and first-roller's reduction ratio.The result shows that the absolute value of the axialresidual stress in the axial stability phase is less than the initial and final spinning phases,while the tangential and radial residual stresses are opposite;the axial and tangential residual stresses are compressive stress in the exterior of the wall thickness direction,which gradually transitions to the tensile stress from the outer to the inner.The variety is generated at about1/2 of wall thickness,and the absolute value of the external compressive pressure is greater than the internal tensile stress.The calculated residual stress nearly satisfies the self-balancing condition in the wall thickness distribution;The outer surface and inner surface of the radial residual stress are positive but the middle is negative;the axial and tangential residual stress increase with the increase of the thinning rate,and first decrease and then increase with the increase of the feed ratio,and decrease with the increase of the first-roller's reduction ratio.In order to obtain the sequence of influence of technological parameters on residual stress and the optimal combination,an orthogonal test was designed in this paper to measure the residual stress after stripping by the method of X-ray diffration.The results show that the first-roller's reduction ratio has the greatest influence on the axial and tangential residual stress,and the thinning rate is second,but the influence of technological parameters on the axial residual stress is greater than the tangential residual stress;and finally the optimal combination of technological parameters is obtained according to the actual production(the thinness rate is 35%,and the feed ratio is 0.6mm/r,and the first-roller's reduction ratio is65%).At the last,residual stress of the optimal combination is compared with the simulation's.The numerical value is slightly smaller than the simulation's,but the distribution law is nearly consistent.