Simulation based prediction of ring creep on a planetary bearing of a 1MW wind turbine gearbox

Abstract

Wind turbines (WT) must be further optimized concerning availability and reliability. One of the major reasons of WT downtime is the failure of gearbox bearings. Some of these failures occur due to the ring creep. Ring creep is a failure mechanism, which is mostly detected in the planetary bearings. Ring creep describes a relative movement of the outer ring to the planetary gear. In order to improve the understanding of ring creep, the finite element method (FEM) is used to simulate ring creep in a full-scale planetary bearing (NJ2330) of a 1MW WT planetary gear. The simulation results are validated with experimental data, obtained on a nacelle test bench. The study shows that the simulative prediction of ring creep is of the correct order of magnitude, but no accurate prediction of ring creep can be made without accounting for manufacturing tolerance classes.