Experimental and Numerical Investigation of Hydraulic Losses in Rolling Bearings

摘要

The optimization of components and processes has a great importance because even a small development of the efficiency could save a huge amount of energy and material in long term. An essential part of the optimization is the identification of the sources and the influencing factors of the losses. This is the same in our current topic, in the case of rolling bearings. During the operation of an oil-lubricated rolling bearing, losses also occur which can be divided into two groups. The first group is the load-dependent losses or contact losses which are resulted from mechanical friction due to contact forces. For the determination of these losses, there are suitable calculation methods and Multi Body Dynamics Simulation techniques [1]. The second group is the load-independent losses caused by lubricant displacement and lubricant shearing on the surfaces of the components. The aim of our project is to investigate this group, which is generally referred to as hydraulic losses. In contrast to contact losses, the number of the available calculation approaches for determination of hydraulic losses is limited. There are only same empirical models or numeric methods with high power and computing demand. Therefore, experimental and numerical investigations were carried out in the frame of a cooperation project in order to get know about the load-independent hydraulic losses in more detail. The experimental part was performed at the Institute of Machine Elements, Gears & Transmissions (MEGT), and the simulations at the Institute of Tribology and Energy Conversion Machinery (ITR). The project focuses on fully- and half-flooded lubrication with tapered roller bearings where the influence of the environment close to the bearing is also taken into account as an influencing factor.