On dynamic responses of gear transmission system during rough tooth surface worn

Abstract This study investigates the dynamic responses of gear systems while considering the morphology of worn gear tooth surfaces after different working times. Specifically, the anisotropic three-dimensional micro-morphology of the rough tooth surface model is established based on the W-B fractal theory. The non-uniform wear of the rough tooth surface under different rotational speeds and working hours is quantified according to Archard’s theory. The time-varying meshing stiffness (TVMS) and backlash are calculated with the wear values and then serve as internal excitation input parameters of the dynamic model. The dynamic responses are solved with the variable step Runge-Kutta algorithm. The results show that with increasing gear rotational speed and durations, the depth of tooth surface wear increases gradually, leading to a decrease in TVMS and an increase in backlash. The gear transmission system, considering the micro-morphology of the tooth surface, exhibits diverse dynamic response characteristics as speeds vary. With prolonged working hours, the system’s dynamic response transitions from periodic motion to chaotic motion, manifesting as chaotic vibrations, which are detrimental to steady operation. Transmission systems in chaotic motion can be transformed into stable periodic motion by adjusting the torque or rotational speed of the gears. The findings can provide theoretical guidance for selecting suitable operating conditions for gears subject to different wear degrees.