Constructing Fast and Representative Analytical Models of Wind Turbine Main-Bearings

Abstract

Abstract. This paper considers the modelling of wind turbine main bearings using analytical models. The validity of simplified analytical representations used in existing work is explored by comparing main bearing force reactions with those obtained from higher fidelity 3D finite element models. Results indicate that there is good agreement between the analytical and 3D models in the case of a non moment-reacting case (such as for a spherical roller bearing), but, the same does not hold in the moment reacting case (such as for tapered roller bearings). Therefore, a new analytical model is developed in which moment reactions at the main bearing are captured through the addition of torsional springs. This latter model is shown to improve the agreement between analytical and 3D models in the moment reacting case. The new analytical model is then used to investigate load characteristics, in terms of forces and moments, for this type of main bearing across different operating points and wind conditions.

Wind turbine main-bearing lubrication – Part 2: Simulation-based results for a double-row spherical roller main bearing in a 1.5 MW wind turbine

“…Main-bearing research to date has mainly focused on load modelling (Kock et al, 2019;Hart, 2020;Wang et al, 2020;Zheng et al, 2020a;Stirling et al, 2021), load characteristics (Cardaun et al, 2019;Hart et al, 2019;Hart, 2020;Guo et al, 2021) and implications for fatigue damage (Zheng et al, 2020b;Loriemi et al, 2021). Lubrication conditions within the main bearing are generally not considered.…”

“…Load inputs to the Hertzian model are then determined using a simplified drivetrain representation and a static load balance, between applied hub loading and main-bearing force response, at each time step (Hart et al, 2019;Hart, 2020). This approach is possible due to the statically determinate nature of three-point-mount drivetrains in which the main bearing provides a force reaction only (Stirling et al, 2021), as is the case here. In Stirling et al (2021) it was shown that this simplified drivetrain representation is able to accurately recreate the radial response at the main bearing seen in a higher-fidelity, but still relatively simple, 3D finite element model.…”

“…This approach is possible due to the statically determinate nature of three-point-mount drivetrains in which the main bearing provides a force reaction only (Stirling et al, 2021), as is the case here. In Stirling et al (2021) it was shown that this simplified drivetrain representation is able to accurately recreate the radial response at the main bearing seen in a higher-fidelity, but still relatively simple, 3D finite element model. All thrust is assumed to be reacted by the main bearing.…”