Design&Analysis Of DF7Diesel Engine Crankshaft

The crankshaft is the main moving part sof the internal combustion engine.Its size largely affect the whole size and weight of the internal-combustionengine, the reliability and durability of the engine also depends largely on thestrength of the crankshaft. In recent years, with the rapid improvement ofvehicular diesel engine performance and reliability,at the same time, the moreand more stringent regulations related to vehicular engines, the peak cylinderpressure becomes more and more higher.it is becoming an important issue toimprove the strength and reduce the vibration of crankshaft at the condition ofthe limited size. Therefore, Optimizing the structure of the crankshaft, Doingtorsional vibration and strength strictly calculation analysis and safetyevaluation of the diesel crankshaft system is an important task duringdeveloping a new diesel engine.The main work of this paper is the design and simulation of crankshaft forthe development of a middle-duty diesel engine of DongFeng commercialvehicle company.Based on experience, the main parameters of crankshaft wereselected refer to the similar engine according to the engine developmenttarget.Then the balance of crankshaft were analysed via Pro/E CAD softwareand DAIL simulation package（swhich is developed by ourselves）. And bearinglubrication was also analysed via special software.By simulation.the primarystructure and layout were decided.After the equivalent parameters，such as themoment of inertia and torsion rigidity, in equivalent model of DF7dieselcrankshaft system are determined by PRO/E software and Hyperworks softwareand the empirical formula. based on equivalent model of engine crankshaftsystem and the system matrix method, the calculation analysis of free torsionalvibration and forced torsional vibration of DF7diesel crankshaft system.wereperformed via DAIL software. a new viscous damper is developed andvalidated by torsional vibration experiments. Finally, using Hyperworkssoftware and DAIL software,The stress of crankshaft were calculated Based onreliability method--stress–strength interference theory The reliability analysisof crankshaft was completed, comparing with the fatigue test results, theresults show that the strength of the crankshaft meet the reliability requirementof DF7diesel engine..Through the completion of this project for the future of the crankshaft axisdesign verification establish a set of standardized working process.