Modeling And Simulation Of Dual Mass Flywheel’s Torque Characteristics

When driving, the torsion vibration of vehicle transmission is mainly due to the changing in speed and braking frequently, the irregularity of periodic input incentive in the engine. As an important automotive powertrain component, dual mass flywheel (DMF) has a very good effect in eliminating the torsion vibration of driven system and reducing the noise of transmission gear. Although the signal mass flywheel has some vibration reduction effect, while can not make sure the driven system’s first-order and second-order resonant speeds are beyond the normal speed of the engine.As the breakthrough of key technology particularly in TDI and the great increase of engine’s power and torque, the torque characteristics of DMF is requested more higher so that low torque and small torsion angle should be flexible, high torque and large torsion angle should be of high counter torque become the important goal in the design and research field of DMF. The current development status and trend of DMF are systematically researched, and a detailed study and analysis on the torque characteristics of dual mass flywheel-circumferential short spring(DMF-CSS) are carried out based on the research cooperation with enterprise. The torque characteristics model and amplitude-frequency characteristics which realize the non-linear and high counter torque and vibration isolation of the driven system design goals are obtained by the simulation analysis and forced vibration in ADAMS. The main research is as follows:①The torque characteristics mathematics-mechanical model of the DMF-CSS based on friction was established to discuss the force analysis and the torque’s theory calculation formula of the spring’s work with the primary flywheel and secondary flywheel in the two process of the DMF. The non-linear and high counter torque in the condition of large torsion angle is realized by the mutual friction wedging of the spring holders which proclaims the friction wedging have a great influence on the torque characteristics of the DMF.②To check the correctness of the torque characteristics and the vibration and noise reduction on the driven system in the work process of the DMF, the3D entity model of the DMF was built in Pro/E and the two spring holders were treated to be flexible body in ANSYS12.0. Then the model of DMF was added constraints and loaded to simulate the mutual friction wedging of the spring holders’ surface in the torsion process by leading into ADAMS. At last the analysis model of torque characteristics which was consistent with the test result was obtained.③The torsion and vibration analysis model which was equivalent simplified three quality and two degrees of freedom of the driven system was established. Then the driven system was implemented forced vibration through sine excitation in the vibration module of ADAMS in order to get the amplitude-frequency characteristics. So the vibration isolation design goal that the driven system’s first-order and second-order resonant speeds are beyond the normal speed of the engine was achieved.