Reducing Tolerance‐Induced Spread on Transmission Error in Planetary Gear Stages Using Monte Carlo Simulations and Surrogate Models Acquired From a Design of Experiments Approach

ABSTRACT Significant variations in tonality levels are frequently observed among nominally identical wind turbine drivetrains, both in industrial test setups and during field operations, posing challenges to compliance with noise emission standards. This work delves into the influence of production and assembly variations on static transmission error (STE) within a commercially available planetary gear stage utilized in onshore wind turbine applications. The study evaluates the effects of variations in gear microgeometry and planet pin mounting—conforming to specific quality levels—on the first and second orders of STE, a key parameter linked to acoustic performance. Employing an efficient planetary gear stage model that accommodates full 3D misalignments, combined with design of experiments (DoE) and analysis of variance (ANOVA), the research utilizes surrogate models for constructing response surfaces. These surfaces enable a comprehensive assessment of the impact of specific tolerance modifications on the spread in STE. Simulation results indicate that microgeometry variations in the profile direction exert a more significant impact at lower loads whereas variations in the lead direction predominantly influence STE spread at higher loads. Radial planet pin‐mounting variations show a consistent effect across the entire load range. This underscores the importance of a well‐considered selection of tolerance intervals to reduce the effect of production and assembly variations on a gearbox's noise profile, thereby mitigating STE variability and contributing to reduced noise emissions.