Dynamic analysis and experimental study of a marine gearbox with crossed beveloid gears

Dynamic modeling of beveloid gears is less developed than that of conventional involute gears with parallel axis because of their complicated mesh mechanism and 3-dimensional dynamic coupling. For evaluating the dynamic characteristics of a marine gearbox with crossed beveloid gears more realistically, a systematic dynamic modeling approach was proposed based on the lumped parameter and the finite element method. Considering the time-varying mesh stiffness excitation, time-varying loaded translational transmission error excitation, sliding friction excitation and backlash nonlinearity, a coupled gear–shaft–bearing–housing dynamic model for a marine gearbox with crossed beveloid gears was developed based on the proposed modeling method. Then, numerical integrations applying the explicit Runge–Kutta formula and the implicit direct integration were used to solve the nonlinear dynamic model. The dynamic transmission error, dynamic mesh force, and dynamic equivalent shaft-bearing supporting force were obtained as well as the dynamic response of the housing. Finally, a test rig was established for the marine gearbox with crossed beveloid gears and vibration tests were performed to investigate the dynamic responses. Through analyzing the responses in time domain and frequency domain, the experimental results compared well with the theoretical dynamic results.