Influence of hydrodynamic planetary journal bearings on the NVH-behavior of wind turbines

Abstract The growth of the wind energy sector is confronted with stringent noise regulations, particularly concerning tonal noises from wind turbines (WTs). These tonal noises, originating from drivetrain vibrations such those caused by gear meshing, are transmitted as structure-borne sound through the WT and ultimately emerge into the surrounding environment as sound emissions. Given that tonal noises are irritating to humans, there is a need for early-stage noise, vibration, and harshness (NVH) mitigation. Recently, a trend has emerged towards replacing planetary rolling bearings (PRBs) with planetary journal bearings (PJBs) in the gearboxes of WT drivetrains. This shift offers several advantages, including reduced installation space, increased reliability, and improved vibration reduction, the latter being especially important for complying with noise regulations. Thus, this paper aims to analyze the impact of using PJBs on the NVH behavior of WTs. To achieve this, the dynamic behavior of a generic 5 MW WT under nominal operational conditions is simulated using a multi-body simulation (MBS) model. The findings of this study indicate significant potential for enhanced noise mitigation through the adoption of PJBs, with the bearing main parameters playing a role in the damping characteristics of the bearing.