Back to back planetary gearbox: Influence of non-stationary operating conditions

Planetary gears operate frequently in non stationary conditions. In this paper, a variable input speed excites a back to back planetary gearbox. In order to understand its dynamic behaviour, a torsional model is developed. A suitable change in the mesh stiffness functions is operated in the model. Using the Short Time Fourier Transform, an amplitude-frequency modulation is observed in the non-stationary condition. An extensive experimental study of the back to back planetary gear is performed in order to validate numerical results.