The Range Extender Structural Optimization Design And Vibration Analysis

This study is about one certain type of engine-motor drive system. Engine andgenerator connected by a pair of spline, because a gap exist in spline connection, under theeffect of incentives, power train vibration significantly. This article aims to identify the maincause of the vibration, providing theoretical support for program improvement.First, the research on electric vehicles and engines torsion vibration problems indomestic and foreign programs were summarized. And then using the lumped parametermethod established considering the spline clearance engine-generator dynamics model.Through the establishment of three-dimensional models, formulas and other methods identifymoment of inertia and damping of system, according to the material mechanics theorydeduced calculation of splines meshing stiffness and finite element simulation method hasbeen verified. Second, analysis the system free vibration, draw system natural frequencies,mode shapes and critical speed. Measured cylinder pressure and calculated exciting momentaccording to the engine cylinder pressure. Analysis forced vibration in the MATLABenvironment getting coupling instant impact force curve and torsion angle curve under theengine incentives. Done torque and torsion angular displacement spectrum analyze. Finally,compared the experimental results and theoretical simulation results to verify the correctnessof the simulation model, the article finally, combined with theoretical analysis results,program was to improve on the original design and the new program structure was checked.By comparing the results of the simulation analysis, we found the presence of the gapspline have a significant effect on drive train vibrations. Under the action of the engineexcitation, spline tooth instant impact by continuous torque. Torque size has relationship withengine speed, load and the spline clearance. Torque on Second frequency of the engine islarger magnitude. Instant impact torque is the important reason of spline tooth wear andvehicle noise.