Probabilistic analysis of the mesh load factor in wind-turbine planetary transmissions: tooth thickness errors

Abstract

This manuscript presents a probabilistic analysis of the mesh load factor in planetary transmissions destined to the wind-turbine industry. This work main goal is to stochastically evaluate the impact of the planetary gears manufacturing processes uncertainties on the transmission performance, depending on their geometric configuration. In order to establish this analysis, the tooth thickness error effect on the transmission performance is chosen, and several tolerances considered in DIN-3967 are statistically analysed. In this regard, two statistical methods -Monte Carlos Method and Taguchi´s Method - are compared for equally spaced in phased and sequentially phased configurations. This comparison allows to assess the accuracy of both methods, taking into account the significant difference in the necessary number of cases, which reaches 20,000 for Monte Carlo´s. Furthermore, a tolerance sensitivity analysis was performed to assess the influence of the errors size on the transmission performance, represented by its mesh load factor. Finally, the results show the number of non-valid transmissions compared to the threshold set by the IEC-61400.