INFLUENCE OF HEAT GENERATED IN A ROLLING BEARING ON ITS MOTION RESISTANCE

The heat generated in a bearing may affect its resistance to motion. Therefore, the bearing seat designer should take this into account in the design process. The article presents the results of simulation tests which show how the heat in the bearing affects its resistance to motion. A methodology for determining the resistance to motion and power losses in the bearing has been proposed, which consists of two stages: identification of the temperature distribution in the bearing and identification of thermal deformation and contact loads. The main results of the research are the following statements: that the thermal deformation of the bearing elements is much greater than that due to mechanical loads (centrifugal forces or pre-load) and the contact loads, thus the motion resistance and power losses in the transient state may be much greater than in the state fixed. The conducted experimental studies show a relatively good qualitative agreement with the results of simulation tests, while the quantitative results do not always provide a sufficient agreement. The most important conclusion from the research is as follows: for high-speed assemblies, e.g. spindles of High Speed Cutting machine tools, the failure to take into account the motion resistance due to heat generated in the bearing may lead to a reduction in bearing life.