Failure Analysis And Torsion Emulation On Main Drive System Of Track-Laying Vehicle

The torsional vibrations of drive systems exist in most power equipments, In this study, the multi-body system dynamics is used to investigate the torsional vibration problem of the drive system of tracklayer bulldozer. The basic theory and conception of the multi-body system dynamics are introduced firstly, and then the torsional vibration of damper is calculated with the analysis above.The failure phenomenon of coupling and universal-joint trunnion has often taken place since they were put in production. For this purpose, the crack surface of them is studied firstly. The static load strength and fatigue strength of main components are tested and analyzed in the ANSYS software. 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 ADAMS software is used for dynamics and kinematics emulation of drive system without damper to obtain the natural frequency. Meanwhile, the breakdown torque speed is calculated according to the relational expression of the whirling speed and natural frequency. The analysis above indicates that the resonant fatigue failure of drive system occurs when the tracklayer bulldozer works near the breakdown torque speed. The engine speed at the normal state is recorded in order to validate the accuracy and feasibility of the conclusion. The results confirm that the work time of the bulldozer near the whirling speed is more than 50% of all time at normal state. So the breakdown torque speed is adjusted, and the drive systems of different rotary inertia of flywheel and different spring stiffness are analyzed. Consequently, the reasonable program of adjusting the breakdown torque speed is that the rotary inertia of flywheel 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 drive system of tracklayer bulldozer is improved, and the failure proportion of drive system decreases greatly. So the accuracy of theory analysis and the emulating model is demonstrated.