General presentation > Keynote speaker

Dr. Michal Wasilczuk

Associate Professor, Gdansk University of Technology

Gdansk, Poland

Biography

Michal Wasilczuk received his M.Sc. (1986), Ph.D. (1994) and D.Sc. (2005) from the Gdansk University of Technology.

Currently he is an Associate Professor and Head of the Department of Machine Design and Automotive Engineering at the Faculty of Mechanical Engineers at GUT and a Project Manager at A&O Expert consulting company.

Bearing systems and tribology are the main fields of his scientific and engineering interest - starting from the Ph.D. devoted to the research of a hydrodynamic axial bearing with an elastic thrust plate. In 1998, the team at GUT started their work on large thrust bearings of hydroelectric power plants. This work comprised troubleshooting, field tests, development of calculation and test methods, as well as the design of bearings for modernized power plants. The research programs were financed by the Polish Ministry of Science and Higher Education and by various companies including major hydro-generators manufacturers. Three PhD dissertations were completed under his supervision.

His experience in the field of large thrust bearings is described in an entry of “Encyclopedia of Tribology” published in 2013 by Springer and in the book “Large Size Hydrodynamic Thrust Bearings” published in Polish in 2013.

Should we seek further improvement of fluid film bearings - what for and how?

Fluid film bearings have been extensively used in the industry because of their unbeatable durability and extremely low friction coefficient. Large bearings supporting shafts of huge and important rotating machines constitute a special group of fluid film bearings since the reliability of crucial systems, like for example electro-energetic system, rely on their trouble-free operation. Large thrust bearings, apart from enormous consequences of failures, can also be characterized by severe conditions of operation. Despite very low coefficient of friction due to large diameters, dissipation of energy in such bearings is noticeable.

In the contemporary economy with ever growing demands for increased efficiency there is always a need for improving performance of the machines. Two main aspects of increasing the efficiency can be distinguished - one is literal - the machines have to be more efficient so the losses, including friction in the bearings, have to be minimized. For example, in case of hydroelectric generators, part of the hydraulic energy dissipated in the bearings is not converted to electric energy. In this way, the attempts to decrease losses in the bearings have the same importance as the attempts to improve the geometry of the rotors of the water turbines. It seems that much effort has been put into direct methods of increasing the efficiency while the attempts to decrease the bearing losses have been neglected in the past. Looking at the components of losses in fluid film bearings one can notice that apart from unavoidable losses in the film, there are losses generated outside the film which can possibly be avoided or decreased by bearing modifications, such as special systems of lubrication which do not require fully flooded bearing housings. Some other possibilities of decreasing energy losses in the fluid film bearings will also be discussed in the paper.

The other aspect of increasing overall efficiency of the machines is decreasing their downtime and limiting the number and consequences of failures. Unfortunately, in the hydrodynamic bearing, there is a contradiction between energy efficiency and margin of safety, very well shown by the Hersey curve. Therefore, in order to allow more efficient, and in the same time more risky, bearing operation it is necessary to predict bearing performance using more accurate bearing models, but since the bearing failures can be caused by a variety of reasons it is also important to improve bearing diagnostic tools to be able to prevent their failures. This requires the development of measurement and diagnostic methods as condition monitoring based only on direct temperature measurement proved to be ineffective in numerous cases. The idea of active bearings is probably one of the solutions combining both aspects of efficiency - they can be energy-efficient and reliable in the same time.