Influence Of Contact Stress And Wear Of Lubricant Films On Cam Research

Cam is the major components of valve body valve for precise opening, engine cam fordesign reasons, common failure phenomena of surface wear. This cam diesel engine for thestudy, using dynamics model of quality programming in MATLAB software environment, inADAMS software build dynamic simulation models, respectively, calculation and analysis ofcam in contact stress of diesel engine speed calibration, and for mutual authentication,discussed the difference exists because both its results. According to get cam contact stress,judge prone to wear and tear and wear of cam forms. Application of MATLAB softwaredesign has developed a program, calculated the cam under the rated speed of minimum oilfilm thickness and film thickness ratio, discussion on lubricating oil temperature, cam andtappet surface roughness and effect of different lubricating condition on wear of cam, camdesign and made recommendations for improvement.Establishing the quality of valve train dynamic models, according to the valve bodyparameters, function fitting tappet lift and application of MATLAB software write calibrationspeed cam contact stress of diesel engine programs. Simulation results show that maximumvalue of contact stress in cam peach-tip site. Under the rated speed, larger cam contact stresscurve amplitude, indicating that this distribution mechanism under the condition of largevibration.Based on the structure parameters of the diesel engine valve train parts, with ADAMSsoftware distribution mechanism dynamics simulation model. Contact stress simulation forcalibration of diesel engine speed, mutual authentication and single quality dynamic modeland its results. Simulation results prove theoretical calculation and simulation analysis of theresults of basic line; By contact stress curve, contact stresses are cyclic changes, occurred in cam peach-tip contact, contact stress reaches a maximum value, and the minimum curvatureradius of cam, easily lead to cam wear.According to cam Elasto-hydrodynamic lubrication of minimum oil film thickness andfilm thickness calculation method, using MATLAB to write calibration engine speed camminimum oil film thickness and film thickness than the program, simulation when workingdraw-tappet cam contact position of lubricant film thickness and film thickness ratio. Resultsshowed that cam peach-tip region of minimum oil film thickness, boundary lubrication,friction enough to be separated by oil-film on the surface. At the same time, sliding speed andload in the region relatively large and easily of led cam failure. -Tappet cam contact stresscalculation of calibration of diesel engine speed, maximum contact stresses location positionsconsistent with the minimum oil film thickness, oil film easy to puncture and-tappet camfriction surfaces in direct contact, wear occurs. Thesis discussion on lubricating oiltemperature and-tappet cam effect of surface roughness on wear of cam, as the lubricating oiltemperature, oil film thickness and film thickness ratio decreased; When the roughnessdecreases, film thickness than a larger trend, lubrication improved significantly.