Research On Dynamic Characteristics Of Heavy-duty Cross Cardan Drive System

The heavy-duty cross cardan drive system is composed of some elastic parts and inertia parts, such as motor, cross universal couplings, gear distribution box and connecting shaft, etc. The heavy-duty cross cardan drive system has the characteristics of large transmission torque, big impact and so on. The cross universal coupling is the key component of the system. Based on the main transmission system of the mill, the torsional vibration characteristics of heavy-duty cross cardan drive system is studied in this paper.Main works of this article are as follows.First, the mechanical model and the mathematical model are established for cross cardan drive system torsional vibration. Based on the mathematical model the system’s inherent characteristics of the twisting vibration are analyzed. Inherent characteristics of system include natural frequency and vibration mode. The natural frequency sensitivity of rotational inertia and torsional rigidity are discussed in this paper. By the calculation result, the natural frequencies of the system are respectively9.1Hz,33.07Hz,41.88Hz,110.48Hz and159.18Hz. The rotational inertia and torsional stiffness of the cross universal are the biggest influence on the natural frequency of the system. The system’s modal flexibility of different orders is studied in this paper. And the distribution of the elastic potential energy is discussed. Therefore the main mode of the system is determined. According to the calculation result, the shaft which is composed of cross universal couplings has large elastic deformation and tends to cause fatigue fracture in the entire system. So the shaft should be paid more attention to in the operation condition.Next, the system’s dynamic response is studied in this paper. And the various spindles section’s torque amplification factor (TAF) is obtained. The torque amplification factor of different spindles is respectively1.13,1.75,2.98,1.61and1.55. It is concluded that the spindle design is reasonable. Comparing to the torque amplification factor, the weak link can be found. The general method of cross cardan drive system’s torsional vibration dynamic response with clearance is discussed in this part.Finally, the cross universal coupling is analyzed by the finite element analysis software ANSYS Workbench. The3D entity models of heavy-duty cross universal coupling are established according to the drawings. The key parts’distribution of stress is obtained through ANSYS Workbench. The equivalent stress values of the key parts are as follows. The maximum equivalent stress of the cross shaft is731.9Mpa. The maximum equivalent stress of the jaw is564.6Mpa. The maximum equivalent stress of the connecting shaft is418.91Mpa. According to the calculation result, the maximum equivalent stresses of the key parts are far from reaching its ultimate strength. The modal characteristics of the cross universal coupling are obtained by ANSYS Workbench.