Aerated Oil in the Rotating Channel

<div>In this article we examine the behavior of oil in the lubrication channel between the main bearing and the connecting rod bearing in the crankshaft of an internal combustion engine. The requirement for high service life and proper operation of these bearings, while minimizing input power of the lubrication system, lead to the need to understand the function of these structural parts in detail. To simulate and visualize this process, an experimental device was created. The device allows the experimenters to change individual parameters such as rotation speed, oil pressure, oil temperature, and aeration, while simultaneously visualizing the process with the help of a special rotating camera. These parameters are then obtained by image processing. In this way, the following influences are investigated here: at oil temperatures of 30, 50, and 80°C, relative oil pressures of 1, 2, 3, and 4 bar, at undissolved air in the oil of 5 and 10 vol% and crankshaft station speeds from 0 to 6000 1/min. The work is inspired by previously known publications by other authors. Their results were obtained mainly using computational methods. In the case of experiments, the authors used indirect methods of measurement using pressures and flows. Therefore, this work has a great contribution in the experimental area. The results of the experiments show the influence of the tested parameters on the gradual limitation of the oil flow through the channel. At a relative oil pressure of 1 bar and a crankshaft speed of 6000 1/min, the pressure even drops to 0 bar, and the oil flow through the channel collapses. The results of image processing show not only the area of the channel filled with oil, but also the distance of the beginning and end of the air bubble from the beginning of the channel.</div>