Research on dynamic characteristics of dual-branching gear system

A translational-rotational coupling dynamic model for a dual-branching gearbox with two stages was established. The model considered the factors as the time-varying mesh stiffness, the stiffness of oil film of journal bearings, damping, random tooth errors, assembling eccentric errors, and so on. The vibration modes of the system could be categorized into rotational mode and translational mode by observing the natural frequencies and the characteristics of mode shapes. The dynamic equations were solved using Fourier Series Method and the dynamic mesh forces on the gear pairs of the stages. The results show that the dynamic mesh forces have a little difference between each mesh cycle as the influence of the random tooth errors, which coincides with the manufacturing fact. The assembling errors of the gear shaft and the stiffness of connecting shaft between two stages have both great effect on the vibration and load sharing of the system.