Study On Main Bearing Deformation Characteristics And Influence Law On Internal Combustion Engine

Crankshaft as the key parts of reciprocating compressor,they bear alternating loadvarying with time periodically during operation,which making the crankshaft and mainbearings subject to deformation of different degree.It is not only affecting the life of itsown,but also relating to the security and stability of the engine.at the same time,there are alot of negative effects on service life and performance of the other parts.So the dynamicsanalysis especially deformation coordination between the crankshaft and main bearingstructure has become a major topic in the study of internal combustion engine reliability.This paper is studied around the following three subjects:1.The methodology on describing the deformation of crankshaft and main bearings.The deformation evaluation of round parts was studied,based on the theory of formand position error.Including the description of loss of roundness, holistic alignment, circularrunout and cylindricity about the main bearing;the evaluation index of mathematicaldefinition was converted to the algorithm code,calculation methods of coordinationdeformation about crankshaft-main bearings were studied.2.The study of the dynamic characteristics and influence law about crankshaft andmain bearing.The dynamics simulation analysis of crankshaft-Main bearing structural use AVLEXCITE dynamics and finite element methods,based on V12diesel engine. The torsionalvibration characteristics of the crankshaft system of the V12engine are acquired, and arecompared with experimental results. The coordinated deformation between crankshaft andbearing was studied by using each of the main bearing gap and journal tilt angle,and thestudy of main parameters affecting coordination deformation of crankshaft and bearingsuch as speed,bearing radial clearance and load, are completed.3.On the deformation analysis of single and multiple main bearing.The FEM models of crankshaft and body are established,the analysis of bearingstiffness under preload conditions, interference condition and film load conditions,the studyof main parameters affecting coordination deformation of bearing are completed,which willprovide some suggestions in the bearing design.