Simulation of ring creep in tapered roller bearings on a test rig for wind turbine bearing units
Peter Grosse
Summary
In the ongoing research project “WEA-RiWa” [1], a model-based calculation method for the prediction of the ring creep of main bearings and planet carrier bearings in wind turbines will be developed. For the validation of this method, the scientists will be testing full main bearing units and planet carrier bearings on full-scale test rigs.
In previous research [2], the authors already presented a new high-fidelity FEM model that simulates the micro-motion in the contact between the rolling bearing inner ring and the shaft in the wind turbine drive train. This model simulates not only the rolling bearing itself, but also the stiffness of the neighboring structure, as this is essential to predict the ring migration effect close to reality and the physical behavior of the device under test.
At Fraunhofer IWES, an existing modular main bearing unit test bench is currently being improved to allow for the validation of the ring creep simulation with measurements. Due to the size of the components and the bearings, there are some challenges, e.g. the creep measurements must be fine enough to detect the micro-movement of the main bearing ring on the shaft even if the components are comparatively large, while at the same time being robust enough to withstand the operating conditions in a wind turbine drive train at full rotation speed. Furthermore, it is required to integrate various measurement systems to allow the validation of the numerical model, while at the same time avoiding any influence from the measurement or its integration on the system being tested.
This publication presents the ring creep simulation results and the subsequent requirements for the test bench. And shows solutions that upgrade the test bench for validating the numerical ring creep model.
[1] www.iwes.fraunhofer.de/en/research-projects/current-projects/wea-riwa.html