Optimization of the Input Shaft Torsional Amplitude of a DCT Gearbox

Zhang Guihui; Shi Lei; Ma Junming; Wang Xiangwen; Sun Hongming; Dong Liyun

doi:10.16578/j.issn.1004.2539.2024.04.020

Abstract：Torsional vibration of the automobile transmission system may cause roar or abnormal noise in the car.Torsional vibration excitation generally comes from the main order of the engine and is transmitted to the gearbox through torsional vibration damper.Therefore,the torsional amplitude of the gearbox input shaft is the first factor to control the torsional vibration of the whole transmission system.A passenger car is equipped with a 6-speed wet double clutch transmission(WDCT).The maximum torsional amplitude of the input shaft of the gearbox from 2nd gear to 6th gear has reached 494.38 rad/s2,which does not meet the design requirement of 400 rad/s2.In order to solve the problem that the torsional amplitude of the gearbox input shaft is too large,this study uses AMESim software to build a torsional vibration analysis model with dual mass flywheel torsional vi-bration damper under full throttle driving condition,taking the engine speed fluctuation signal collected by a re-al vehicle as the excitation source.Through simulation analysis,the influences of the primary mass moment of inertia,secondary mass moment of inertia,torsional stiffness,basic damping torque and free rotation angle of the dual mass flywheel on the torsional amplitude of the gearbox input shaft are determined,and the optimiza-tion scheme of the transmission system is obtained through orthogonal experimental design,and the effective-ness of the optimization scheme is verified by a real vehicle.The research methods and ideas of this study pro-vide a solution for the torsional vibration optimization of the automobile transmission system with dual mass fly-wheel torsional vibration damper.