Analysis of planetary gear transmission in non-stationary operations

摘要

Planetary gearboxes operate usually in non-stationary conditions generated mainly by variable loads applied to these transmissions. In order to understand the dynamic behavior of planetary gearboxes in such conditions, a mathematic model is developed including driving unit, transmission and load. The variability of load induces a variable speed of the transmission which is taken into account when characterizing the main dynamic parameter of the transmission which is the mesh stiffness function. This function is not periodic following the variability of the transmission speed. The computation of the dynamic response shows an intimate relation between the vibration amplitude level and the load value. As the load increase the vibration level increase. A combined amplitude and frequency modulation is observed which is well characterized using Short Time Fourier transform more suited than the spectral analysis.