Study On Torsional Vibration Of Bulldozer Drive System By Elastic Coupling

The failure phenomenon of coupling and universal-joint trunnion has often taken place since they were put in production. For this purpose, the reason of the fatigue failure is analyzed by crack surface research, finite element analysis and dynamics emulation in this paper. The torsional resonance vibration of the drive system performance parameter is calculated, and the effect of elastic coupling on natural vibration frequency of system is analyzed. Simulation results indicate that the use of elastic coupling can effectively reduce the natural frequency of driver system; the results also provided theoretical data to avoid system sympathetic vibration effectively. Based on the above conclusion, the drive system of tracklayer bulldozer is improved, and the failure proportion of drive system decreases greatly.The crack surface of coupling and universal-joint trunnion is studied firstly, and the analysis has carried out finite element method on key components of the drive system. It is demonstrated that the torsional resonance vibration causes the fatigue failure of the drive system of tracklayer bulldozer. In order to deal with this failure problem, the flexible model of drive system is set up with the ADAMS/Flex module. The frequency and mode of the components are gotten with mode analysis. In ADAMS software, the drive system dynamics model is assembled with flywheel, torque converter, pump pulley, torsional vibration damper and so on. This analysis model is used for dynamics and kinematics emulation of drive system without damper to obtain the natural frequency and whirling speed. The engine speed at the normal state is recorded in order to validate the accuracy and feasibility of the conclusion.So the breakdown torque speed is adjusted, and the drive systems of different elastic coupling stiffness are analyzed. The general rules of structure modification's influence on system vibration behavior is researched and simulated. Consequently, the reasonable program of adjusting the breakdown torque speed is that the stiffness of elastic coupling is set to match the one of the whole drive system and the breakdown torque speed of drive system should be out of the normal running rotational speed. Based on the above conclusion, the basic model of elastic coupling is designed, assembled and simulated. The result shows that the elastic coupling has better damping effect of the drive system of tracklayer bulldozer.