Uncertainties in Heat Loss Models of Rolling Bearings of Machine Tools

The mastering of the thermal behavior of machine tools is an important task to increase the machining accuracy. Tools that are progressively used for this task are models that simulate the thermal behavior of the machines. A main part of the models is the representation of heat loss processes. An example of these processes is the friction in rolling bearings. The model approaches available to describe the bearing friction show a high degree of uncertainty. The causes and consequences of these uncertainties are investigated on the example of the representative Palmgren friction model for rolling bearings. Thereby especially bearings on feed axes are considered. The results are quantitative statements regarding individual uncertainties. These can now be used to estimate the overall uncertainty of the model under specific operational conditions and model assumptions. This improves the understanding of heat loss modeling and will be the basis for future model enhancements.