Analysis Of Connecting Rod Bushing Lubrication Characteristics Considered Journal Misalignment

Connecting rod bushing is one of the key friction pair in engine, which workingcondition is so bad that there is a very important theoretical significance and practical value toanalysis its lubrication performance. In connecting rod bushing working process, due to thedeformation of connecting rod by force and assembly error, piston pin axis and connectingrod bushing axis is often not in a parallel state. In order to fit the actual, this paper studiedthe characteristics of connecting rod bushing lubrication on the basis of consideringconnecting rods’ load deformation and bushing surface, when piston pin axis and connectingrod bushing axis is not parallel.Firstly, kinematics and dynamics are analyzed of engine crank connecting rodmechanism in this paper. According to the working cycle of the engine, the connecting rodbushing dynamic force were analyzed and calculated, then obtained the rod bushing loadingcondition, which provide a theoretical basis for calculating oil film pressure and surfaceasperity bearing.Based on the EHL theory, average flow model and the asperity contact model,misaligned journal connecting rod bushing’s lubrication characteristics were analyzed. Inconsideration of surface compressive deformation of the connecting rod bushing,established the film thickness equation on condition of the misaligned piston pin inthe connecting rod bushing, calculated the oil film pressure distribution, oil film thicknessdistribution and surface asperity bearing characteristics in this condition.The surface deformation effect on connecting rod bushing lubricationcharacteristics considering journal misalignment was discussed, analyzed the lubrication stateunder different tilt and tilt angle, studied different misalignment angle neck and roughnesseffect on surface asperity bearing, then, the rod bushing lubrication in case of the same crankshaft speed has different journal angle and same journal angle hasdifferent crankshaft speed was compared, all these work provided a theoretical basis for amore precise analysis of connecting rod bushing lubrication characteristics.