Lightweight Design And Research For Crank-link Mechanism On Marine Diesel Engine

This paper takes the crankshaft,connecting rod and crank-link mechanism as the research object,which belongs to a certain type of the Marine diesel engine.Respectively,based on the theoretical analysis and simulation,the kinematics and dynamics characteristic of crank-link mechanism has been carried on.For the key parts such as crankshaft,connecting rod,the finite element method(FEM)analysis and lightweight design have been made.After the end of lightweight components,static performance simulation,dynamic performance simulation and mechanism performance have been carried out.First of all,in combination with the drawings of the diesel engine crank rod system,achieving precise modeling and assembly in Pro/E.Then based on the theoretical knowledge of kinematics and dynamics,the movement rule of crank-link mechanism as well as the dynamic force are analyzed.Further,in order to provide boundary conditions for the subsequent finite element analysis,using the Pro/E and ADAMS software to complete kinematics and dynamics simulation on the crank-link mechanism.Secondly,lightweight design process and related theories are studied and summarized,then applied to the lightweight design of the crankshaft and connecting rod.Based on the topology optimization relevant theories and the stress distribution results which got from the finite element analysis of the crankshaft and connecting rod.And further to realize the lightweight design of the crankshaft and connecting rod.The result is the crankshaft reducing weight 100 kg,weight loss ratio is 5.5%.And the connecting rod reducing weight is 2.25 Kg,weight loss ratio is 5.64%.Finally,the light-weighted crankshaft and connecting rod had been put into action to verify the static and dynamic performance analysis.For the parts,the static strength analysis,fatigue analysis and modal analysis which is the basis of dynamic analysis,were adopted to verify the static and dynamic performance;For the mechanism,comparing the influence on the main bearing load between the original parts and lightweight parts.Then results show that after the lightweight,the dynamic and static performance of the con-rod and crankshaft meets the requirements,the main bearing load also has a tendency to decrease,so this set of lightweight design method is feasible.