Dynamic Analysis of Planetary Gear Transmission Under Time Varying Loading Conditions

Planetary gearboxes are usually used in several hard work conditions. In fact, they are well known for their symmetrical structure which allows an equal share of the total external torque applied between the planetary gears, the sun and the ring. However non stationary conditions of work such as overload conditions, torque fluctuation during the start-up process in diesel engines and environmental conditions, may affect seriously and unpredictably the dynamic behavior of a planetary gear transmission. As part of an effort to understand this aspect, the present study assessed the impact of external load fluctuation on a planetary gearbox dynamic behavior. For this, a model of planetary gearbox vibration using the lumped mass approach was developed. The model includes effects such as variable tooth mesh stiffness and non stationary external load. Numerical simulations are carried out using a Newark based algorithm. The dynamic vibration results were analyzed using frequency spectrum analysis and develop analysis. Discussion and results are included based on the overall results and analysis.