Search results for: Tribology
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TRIBOLOGY INTERNATIONAL
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TRIBOLOGY LETTERS
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Tribology of the cartilage cells in the intelligent bioreactor
PublicationW badaniach analityczno-numerycznych wyznaczone zostały pola prędkości przepływu lepkosprężystej, odżywczej nienewtonowskiej cieczy biologicznej, a także powstające siły tarcia w trakcie hodowli w warstwie granicznej wokoło powierzchni hodowanych komórek w bioreaktorach, stawach człowieka oraz w szczelinach mikrołożysk. Dodatkowo rozpatrywane będą przepływy potencjalne płynu stawowego z jamy stawowej, które odżywiają chrząstkę...
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Tribology of stochastic phenomena on the hard tissue.
PublicationPraca przedstawia model matematyczny zjawisk tribologicznych podczas hodowli tkanek twardych, w tym chrząstek stawowych. Uwzględnia się chropowatości powierzchni hodowanych chrząstek. Problem tribologiczny uzewnętrzniony został koniecznością sterowania wartościami sił tarcia jakie powstają w cienkiej warstewce przyściennej opływanej tkanki cieczą biologiczną w trakcie hodowli. Taki model matematyczny nie był do tej pory rozpatrywany.
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Tribology of bone tissue culture in bioreactor.
PublicationOpracowano system tribologiczny powstających sił tarcia w bioreaktorze. Pomimo, że wartości sił tarcia osiągają wartości poniżej 0,1 N to mają one decydujący wpływ na wartość porostu tkanki. Mechanika opływu tkanki cieczą o właściwościach biologicznych nienewtonowskich oraz hydrodynamiczna teoria opływu warstwy przyściennej jest bazą wyznaczania parametrów trybologicznychniniejszej pracy.
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TRIBOLOGY TRANSACTIONS
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Ionic liquids as an example of lubricating oils used in a field of tribology
PublicationPodczas prezentacji ustnej pokazano przykłady cieczy jonowych, ich możliwości w wykorzystaniu jako zastąpienie tradycyjnie używanych dziś smarów. Ponadto dokonano porównania kilku właściwości "tribologicznych" między cieczami jonowymi a obecnie wykorzystywanymi smarami
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Tribology Online
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Tribology in Industry
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Mocaxue Xuebao/Tribology
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Ecology In Tribology: Selected Problems of Eliminating Natural Oil-Based Lubricants from Machine Friction Couples
PublicationThe elimination of mineral oil-based lubricants from machines has multiple beneficial effects on the natural environment. Firstly – these lubricants are a direct threat to the environment in the event of leaks; secondly – their elimination reduces the demand for crude oil from which they are obtained. In addition, in many cases, e.g. when replacing traditional lubricants with water, friction losses in the bearings can also be reduced...
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Calculation of flatness errors formed on the tool during finishing machining by lapping. Second International Tribology Conference, SITC 2002.
PublicationPłaskość przedmiotów obrabianych zależy głównie od płaskości narzędzia stosowanego w docieraniu. Orientacja przedmiotu na docieraku musi być wyznaczona w celu określenia korelacji pomiędzy błędami płaskości obu powierzchni. Metoda wyznaczania błędów niepłaskości narzędzia przedstawiona została w referacie. Pokazane zostały przykładowe położenia przedmiotów o różnych kształtach na czynnej powierzchni docieraka z błędem wklęsłości.
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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART J-JOURNAL OF ENGINEERING TRIBOLOGY
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Tribologia biołożysk i inteligentnych bioreaktorów problemem grantu europejskiego = Tribology of biobearings and intelligent bioreactors as the main problem of euro-project
PublicationPraca przedstawia kluczowe problemy związane z organizacją współpracy z uczelniami niemieckimi i badaniami naukowym przeprowadzanymi w zakresie biomechaniki i biotribologii w ramach grantu europejskiego MTK-CT-2004/2008-517226, którego koordynatorem na Wydziale Oceanotechniki i Okrętownictwa Politechnice Gdańskiej jest prof. Krzysztof Wierzcholski
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JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
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INDUSTRIAL LUBRICATION AND TRIBOLOGY
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Bio and slide bearings: their lubrication by non-Newtonian fluids and application in non conventional systems. Vol.3. Tribology processes for cells human joints and micro-bearings
PublicationW niniejszej monografii przedstawiony został aktualny pogląd dotyczący procesu smarowania stawów człowieka od strony mechaniki, a szczególnie hydromechaniki i metod matematycznych. Wyznaczono pola prędkości przepływu lepkiej, odżywczej nie Newtonowskiej cieczy biologicznej, a także powstające siły tarcia w trakcie ruchu cieczy w warstwie granicznej wokoło współpracujących powierzchni. Dodatkowo rozpatrywano przepływy potencjalne...
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Tribologia: Finnish Journal of Tribology
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Advances in Tribology
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TRIBOLOGY & LUBRICATION TECHNOLOGY
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Tribology-Materials Surfaces & Interfaces
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GUT Tribology
Laboratories* badania tarcia i zużycia materiałów tribologicznych * badania eksperymentalne układów łożyskowych (tocznych i ślizgowych) smarowanych olejem, wodą, zanieczyszczonymi smarami lub smarami smarowanymi * teoretyczne badania wykorzystania modeli zweryfikowanych eksperymentalnie (w tym MES, CFD i FSI) * eksperymentalne badania wytrzymałości zmęczeniowej (łożyska ślizgowe cienkowarstwowe) * projektowanie nowych i modernizacja istniejących...
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On the Possibilities of Decreasing Power Loss in Large Tilting Pad Thrust Bearings
PublicationJournal Menu About this Journal Abstracting and Indexing Aims and Scope Article Processing Charges Articles in Press Author Guidelines Bibliographic Information Citations to this Journal Contact Information Editorial Board Editorial Workflow Free eTOC Alerts Publication Ethics Submit a Manuscript Table of Contents Abstract Full-Text PDF Full-Text HTML...
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Numerical modelling and experimental verification of compressible squeeze film pressure
PublicationThe validity of using the Reynolds equation for compressible squeeze film pressure was tested with computational fluid dynamics (CFD). A squeeze film air bearing was instrumented with pressure sensors and non-contacting displacement probes to provide transient measurements of film thickness and pressure. The film thickness measurements also provided input parameters to the numerical prediction. However, numerical results showed...
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Influence of magnetic field on wear in high frequency reciprocatingsliding contacts
PublicationResults of experimental studies concerning the influence of permanent magnetic field on wear of dry sliding contact operating at short stroke and high frequency are presented. It was found that horizontal magnetic field with different orientations relative to the sliding direction is affecting performance of the contact. The increase in frequency of sliding reduces accumulated mass loss and lowers the surface roughness of the wear...
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The influence oil additives on spread cracks in silicon nitride
PublicationThe paper presents an experimental study of the influence of oil additives (Cl, S, P, cerium dioxide (CeO2)) on spread cracks in silicon nitride. The additives Cl, S, P are bound in molecules in liquid form soluble in the base oil. The CeO2 is purely in powder form in suspension. The use of CeO2 powder was made based on the good results of polishing of silicon nitride. A ceramic angular contact ball bearing was modelled using a...
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Modeling lubricant flow between thrust-bearing pads
PublicationInlet temperature is one of the main inputs in all models for the analysis of fluid film bearing performance. At the same time, inlettemperature distribution and also oil velocity distribution at the inlet are the result of flow phenomena in the gap between the bearingpads. These phenomena are complex and in many cases further affected by any special arrangements of forced oil supply to the gapbetween pads. The reason for such...
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Structural properties of foil bearings: a closed-form solution validated with finite element analysis
PublicationFluid film thickness in a compliant foil bearing is greatly influenced by the deflection of the bearing structure. Therefore, in order to properly model performance of a foil bearing, it is mandatory that the deflection of the compliant bearing structure due to the generated hydrodynamic pressure is determined accurately. This article proposes an easy-to-use two-dimensional model, which takes into account detailed geometry of the...
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The Innovative Research Methodology of Tribological and Rheological Properties of Lubricating Grease
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Characterization of NiTi SMA in its unusual behaviour in wear tests
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Experimental research on water lubricated three layer sliding bearing with lubrication grooves in the upper part of the bush and its comparison with a rubber bearing
Publicationcomposite. Eachofitslayershasanimportantfunction.Speciallypreparedslidingsurfaceensures minimum resistance.Followingrunning-initssmoothnessbecomesveryhighandthebearingmay continue workingunder fluid lubricationregime.NBRlayerensuresbearingelasticity,goodvibration damping propertiesandinsusceptibilitytoshaftaxismisalignment.Theexternalbrasslayermakes fitting thebearingeasier. Experiment resultsoftheconductedresearchwerecomparedwiththoseforarubberbearingof similar...
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Peculiarities associated with testing polyetheretherketone (PEEK) in a model rolling contact
PublicationPolyetheretherketone (PEEK) was investigated using a modified version of the four-ball tester in which the upper forth ball was replaced by a cone in such a way that kinematics of the four-ball configuration were fully preserved. Rotation of the cone enforced orbiting and rolling of the ceramic balls around the polymer cup. The results produced some unexpected peculiarities in the wear of ceramic balls which, in principle, should...
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Effects of surface texturing and kind of lubricant on the coefficient of friction at ambient and elevated temperatures
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The Application of Chitosan as a Modifier for Lubricating Greases Based on Vegetable Oil
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The Tribological, Physico-Chemical and Rheological Properties of Lubricating Grease Produced on Epoxy Resin Base
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Evaluation of turning with different cooling-lubricating techniques in terms of surface integrity and tribologic properties
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Tribological and thermal behavior with wear identification in contact interaction of the Ti6Al4V-sintered carbide with AlTiN coatings pair
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Technological and tribological aspects of milling-burnishing process of complex surfaces
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Water-Lubricated Sintered Bronze Journal Bearings—Theoretical and Experimental Research
PublicationWater lubricated bearings are used from many years in shipbuilding, hydro power and other industries because of their advantages such as: extensive serviceable life, low coefficient of friction, longevity of shaft sleeve, good abrasion resistance, low maintenance required, unit simplicity, no danger of pollution and low price. Various types of water lubricated sliding bearings have been tested at the Technical University of Gdansk...
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Concept of cavitation erosion assessment of austenitic 1.4301 stainless steel based on roughness development
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Effect of manufacturing errors of the pad sliding surface on the performance of the hydrodynamic thrust bearing
PublicationIn the present study, investigation of the effect of manufacturing errors on the performance of large tilting pad thrust bearings has been performed, following a CFD-based Thermohydrodynamic analysis of a single pad. A 3D model has been generated, including the pad, the lubricant film and the corresponding part of the collar. The pad has been assumed to be deformed about the pivot point, due to thrust loading. Manufacturing errors...
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Experimental investigation into surface texture effect on journal bearings performance
PublicationThe aim of this study was to analyse the performance of journal bearings with specially created dimples on the sliding surface and operating under various conditions. The texture was created on the bearing surface that co-acted with the smooth journal; moreover, the variation of the textured surface of the journal mating with the smooth bearing was tested, and the results were compared to those obtained with the standard smooth...
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Marine propeller shaft bearings under low-speed conditions: water vs. oil lubrication
PublicationThe bearings used in shipbuilding, hydropower, and water pumps have undergone a metamorphosis in recent decades. Because of environmental regulations, lubrication with grease or mineral oil is prohibited. Thus, the standard solutions include water-lubricated bearings with polymer bushings or sealed systems lubricated with oil. When properly designed, assembled, and operated, bearings can operate reliably for years. However, specific...
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Acoustic journal bearing – Performance under various load and speed conditions speed conditions
PublicationThe paper presents results of experimental testing aiming at finding out what effect system of piezo-electric actuators (PZTs)attached to an aerodynamic journal bearing has on the magnitude of shaft's motion within the bearing operating at specified speed and load. The results clearly demonstrate effectiveness of PZTs in mitigating the shaft's motion thus contributing to the increased stability of the bearing. This stabilizing...
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Influence of local bush wear on water lubricated sliding bearing load carrying capacity
PublicationOne of main problems concerning water-lubricated bearings is their durability. There are known cases of bearings with life time measured in decades, and some, whose refurbishment was necessary just days after start-up. Obtaining stable fluid film friction plays key role in the durability of these bearings. Unfortunately, their load-carrying capacity is limited due to water's low-viscosity. The conducted experimental...
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Extended duration running and impulse loading characteristics of an acoustic bearing with enhanced geometry
PublicationThis paper presents performance during prolonged running of the acoustic bearing when PZTs are switched off and when they are switched on. The effect of active PZT on shaft’s displacements in X and Y directions is clearly demonstrated. Performance of the acoustic bearing was also assessed when an impulse force was applied to the running shaft at speed. Once again the benefits of having PZTs active are beyond doubt. The instability...
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Properties comparison of rubber and three layer PTFE-NBR-bronze water lubricated bearings with lubricating grooves along full bush circumference based on experimental tests
PublicationWater lubricated bearings have been in industrial use for well over a century. During the last decade their traditional range has been expanded with new, modern products. Despite that fact, certain solutions continue to employ the standard rubber bearing with lubricating grooves located along entire bush circumference. The work presents experimental research conducted on comparable sliding bearings with lubrication grooves along...
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Acoustic journal bearing - A search for adequate configuration
PublicationClassical non-contact bearings are already used in a number of specialist applications but there are somespecialist areas where they cannot be used for variety of reasons and acoustic sliding bearings could be an alternative. The paper presents the quest for a configuration of an acoustic journal bearing and shows that the overall shape of the bearing and its geometry are of a vital importance for the load capacity oft he bearing....
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Microstructure and residual stresses in surface coatings with PTFE reservoirs
PublicationThe paper presents the results of experimental study into the microstructure and changes in residual stresses resulting from sliding and rolling/sliding loaded interaction between metallic surface coatings with embedded PTFE reservoirs and various counter faces. It was found that before testing surface coatings had compressive residual stresses. Molybdenum coating with all types of PTFE reservoirs displayed, as a result of testing,...
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Effect of annealing temperature on slurry erosion resistance of ferritic X10CrAlSi18 steel
PublicationIn the present work, the slurry erosion tests were carried out to investigate the influence of heat treatment on slurry erosion process of ferritic X10CrAlSi18 stainless steel using a slurry pot test rig. X10CrAlSi18 stainless steel was tested in as-received condition and after annealing at three different temperatures: 600°C, 800°C and 1000°C. Degradation of materials due to slurry erosion depends on many factors connected with...
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Water-lubricated stern tube bearing - experimental and theoretical investigations of thermal effects
PublicationThe paper presents research results of thermal phenomena accompanying operation of a water-lubricated stern tube bearing with axial grooves. Experimental tests revealed, that intensity of forced axial flow has strong influence on bush temperature. Numerical simulations focused on investigation of the thermal phenomena under operation of water-lubricated journal bearing showed, that restricted axial flow promotes backflow of the...
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Theoretical study of thermofrictional oscillations due to negative friction-temperature characteristic
PublicationAnalytical study on oscillations of a body on a moving counterbody has been done by assuming imperfect frictional thermal contact and friction that decreases with contact temperature. It has been shown that stick-slip oscillation occurs due to decrease of friction coefficient when the body moves in the opposite direction to the counterbody. Dynamical characteristics, such as conditions for stable sliding and limit cycles, have...
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Analytical Study of Sliding Instability due to Velocity- and Temperature-Dependent Friction
PublicationThe instability of sliding causes deterioration of performance characteristics of tribosystems and is undesired. To predict its occurrence, the motion of a body of a one-degree-of-freedom system with friction is investigated about the steady sliding equilibrium position. The motion equation is formulated with the friction coefficient dependent on the sliding velocity and contact temperature changing due to transient heat conduction...
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Measurement of temperature at sliding polymer surface by grindable thermocouples
PublicationThis paper is devoted to experimental study of capabilities and limitations of grindable thermocouples as applied to polymer materials sliding on metal. Chromel–alumel and chromel–copel grindable thermocouples have been developed and tested for wide ranges of contact pressure and sliding velocity. The background temperature of the sliding surface can be determined as the lower envelope of the signal from the grindable thermocouple....
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Experimental research on water lubricated marine stern tube bearings in conditions of improper lubrication and cooling causing rapid bush wear
PublicationWater lubricated bearings are popular in sliding bearings of marine propeller shafts, turbines and pump shafts. Such popularity is partly due to their simple construction which also means a relatively affordable price. In practical experience one may also observe cases of rapid wear or even malfunctions of this bearings, some of which may be caused by insufficient flow of lubricant leading to overheating. The conducted...
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Centrally Pivoted Tilting Pad Thrust Bearing with Carbon-Based Coated Collar—Experimental Results of Low- and Medium-Speed Operation
PublicationExperimental results of the research on a tilting pad thrust bearing with symmetrical pad support in the conditions of high loads and low speeds are presented in the paper. As described in the literature review, experimental results of tilting pad bearings at low speed/high load regime and transient conditions are rare. Unusual material selection - steel pad against a DLC-type coating on the collar was utilized. Such material combination...
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A comparative performance assessment of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublicationThis work presents the investigation results of a journal bearing lubricated with magnetorheological fluid that is activated by a local constant magnetic field to vary both the local flow resistance and pressure. The bearing performance is assessed via Finite Element Modelling (FEM) and results are corroborated by experiments. The FEM model uses the Bingham model to describe the fluid film. A dedicated test rig is used to assess...
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Experimental research on a hydrodynamic thrust bearing with hydrostatic lift pockets: Influence of lubrication modes on bearing performance
PublicationThe aim of the study is to investigate the performance of a thrust bearing equipped with hydrostatic lift pockets under different lubrication modes. Three types of flat land bearing lubrication modes are studied experimentally: hydrostatic lubrication (HS; forced oil injection to the pockets), hybrid lubrication (HS + HD; hydrostatic lubrication combined with the external forced bearing oil supply) and hydrodynamic lubrication...
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Running characteristics of aerodynamic bearing with self-lifting capability at low rotational speed
PublicationAn aerodynamic journal bearing that is capable of self-generating squeeze-film pressure is presented and its dynamic characteristics investigated numerically and experimentally. A numerical method based on a time marching static model was applied to assess the orbit trajectory path of the rotor upon a perturbation. Experimental results were obtained to validate the effect of the self- generated squeeze-film pressure on the stability...
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Morphology of damage inflicted on brittle polymer in lubricated contact under cyclic static load
PublicationIn this article morphology of damage inflicted on the polymethylmethacrylate (PMMA) plate in static point lubricated contact with a ball made of five different materials under cyclic normal load has been presented. It is argued that the counterface material and lubricating film play an important role in the damage process and the extent of damage inflicted in the PMMA plate.
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Influence of surface roughness topography on properties of water lubricated polymer bearings, experimental research
PublicationW artykule przedstawiono wyniki badań eksperymentalnych, których celem było zidentyfikowanie wpływu ułożenia chropowatości na powierzchni ślizgowej łożyska smarowanego wodą z polimerową panwią. Badania wykazały, że wpływ ten jest mniejszy niż oczekiwano a na własności łożyska ma wpływ głównie wysokość chropowatości.
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Tribological performance of PTFE-metal binary coatings in rolling/sliding contact
PublicationTribological performance of surface coatings with embedded PTFE reservoirs in rolling/sliding contact is reported. Using two different coating materials and two shapes and patterns of PTFE reservoirs test samples in the form of discs were prepared and tested in a four-ball contact configuration under loads corresponding to nominal contact pressure of 0.5 and 1.0 GPa. It was found that one coating, namely aluminium-bronze with embedded...
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Performance of lubricated sliding contact in magnetic field
PublicationResults of experimental studies concerning theinfluence of permanent magnetic field on wear of lubricatedsliding contact operating at short stroke and highfrequency are presented. It was found that horizontalmagnetic is affecting performance of the contact. Thejagged delamination regions produced in the presence of amagnetic field can be regarded as easily undergoing oxidisationbecause oxygen is readily adsorbed there. Magneticfield...
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Synergisms and antagonisms between MoS2 nanotubes and representative oil additives under various contact conditions
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Effect of ageing automotive gear oils on scuffing and pitting
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The lubricant-coating interaction in rolling and sliding contacts
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Evaluation of apparent Young׳s modulus of the composite polymer layers used as sliding surfaces in hydrodynamic thrust bearings
PublicationHydrodynamic bearings with a polymer sliding layer are able to operate in severe conditions, mainly due to favorable properties of the polymers. The goal of this research was to evaluate apparent Young׳s modulus of two types of the polymer composite layers used for sliding surfaces in hydrodynamic bearings, as a function of temperature. The Young׳s modulus was evaluated on the basis of compression tests carried out on samples obtained...
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Experimental comparison of the transition speed of a hydrodynamic journal bearing lubricated with oil and magnetorheological fluid
PublicationA journal bearing test bench is used to find the transition speed between the hydrodynamic and mixed lubrication regimes for a modified magnetorheological (MR) fluid. It is shown that the transition speed of the bearing can be reduced by applying a local magnetic field near minimum film when it is lubricated with the MR fluid, and that this will only marginally increase friction. The lubricating performance of the MR fluid is compared...
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Theoretical analysis and experimental tests of tilting pad journal bearings with shoes made of polymer material and low-boiling liquid lubrication
PublicationSelecting the appropriate bearing system for the rotor requires a good knowledge of the available solutions and the operating conditions of the machine. For newly designed machinery operating in adverse conditions, selecting bearings that ensure correct and long-lasting operation can be extremely challenging. Difficulties in- crease when the machine’s operating parameters are beyond the technical capabilities of available technical solutions....
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Environmentally acceptable lubricants (EAL) compared with a reference mineral oil as marine stern tube bearing lubricant – Experimental and theoretical investigations
PublicationThe purpose of this research is to indicate the potential differences in bearing characteristics resulting from the application of different lubricant types with the same viscosity grade. The effect of different environmentally acceptable lubricants (EALs) on hydrodynamic journal bearing properties is studied experimentally and compared to the properties obtained after lubrication with a reference mineral oil. The results of the...
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The influence of polymer bearing material and lubricating grooves layout on wear of journal bearings lubricated with contaminated water
PublicationThe goal of the present paper is to investigate wear properties of journal sliding bearing operating in the conditions of contaminated water lubrication. Several bearing materials and bearing sleeve designs (differing in the axial grooves position and their shape) were tested experimentally under typical operating conditions in a dedicated test rig, which was equipped with a lubricating system, enabling lubrication with contaminated...
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Multi-objective optimization of tool wear, surface roughness, and material removal rate in finishing honing processes using adaptive neural fuzzy inference systems
PublicationHoning processes are usually employed to manufacture combustion engine cylinders and hydraulic cylinders. A crosshatch pattern is obtained that favors the oil flow. In this paper, Adaptive Neural Fuzzy Inference System (ANFIS) models were obtained for tool wear, average roughness Ra, cylindricity and material removal rate in finish honing processes. In addition, multi-objective optimization with the desirability function method...
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Comparative wear test of journal sliding bearings with sintered bronze and Babbitt alloy bushes lubricated by environmentally acceptable/adapted lubricants (EAL)
PublicationA growing awareness of the negative effects of mineral oils on the natural environment has resulted in the introduction of new regulations related to environmental protection. One of these regulations requires the use of environmentally acceptable/adapted lubricants (EAL) to lubricate marine main shaft bearings, in place of the mineral lubricating oils that have been used for decades. Classification Societies, which supervise...
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Inverse determination of sliding surface temperature based on measurements by thermocouples with account of their thermal inertia
PublicationThis study developed an inverse heat conduction algorithm to determine temperature at a sliding surface taking account of thermocouple thermal inertia. The direct heat conduction problem was solved analytically based on the Laplace integral transform approach. The inverse algorithm was applied to the problem of friction of a brake material against a steel. The experiments were conducted on a pin-on-disc tribometer for three short-time...
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Grease effect on fretting wear of mild steel
PublicationNa stanowisku laboratoryjnym przeprowadzono badania zużycia frettingowego miękkiej stali smarowanej mineralnymi i syntetycznymi smarami zawierającymi także różne dodatki: grafit dwusiarczek molibdenu ZDDP i ditiocarbamat molibdenu, w różnych stężeniach.Badania wykazały istotny wpływ konsystencji smaru i jego właściwości smarnych na zużycie frettingowe miękkiej stali oraz zróżnicowany wpływ testowanych dodatków. Obecność smaru...
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Centrifugal magnetic fluid seals
PublicationSeals perform an important and at times overlooked function in a lubricant system. They prevent or minimize the movement of the lubricant between two surfaces and also minimize the level of contamination in the system. Seals are divided into static and dynamic types. Static seals operate in systems where the mating surfaces do not move relative to each other. In contrast, dynamic seals operate under conditions where the mating surfaces...
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The problems of resistance to scuffing of heavily loaded lubricated friction joints with WC/C-coated parts
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The tribological properties of lubricating greases produced on vegetable base and modified of polytetrafluoroethylene
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The influence of type of dispersed phase on rolling contact fatigue of lubricating greases on mineral base oil
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The Application of Polyvinylpyrrolidone as a Modifier of Tribological Properties of Lubricating Greases Based on Linseed Oil
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Study of the Influence of Heat Convection Coefficient on Predicted Performance of a Large Tilting-Pad Thrust Bearing
PublicationPart of the heat generated by the shearing of the lubricating film during operation of a hydrodynamic bearing is transferred to the bearing components. In the case of the pad, which is usually fully submerged in the lubricating oil, heat is further transferred at the pad free walls to the oil by convection. This mechanism causes a thermal gradient in a pad and, consequently, its thermal deflection. In large hydrodynamic thrust...
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Tribological and nanoscale research on model friction couples intended for hip joint prostheses
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Air journal bearing utilizing near-field acoustic levitation: stationary shaft case
PublicationResults of a study to examine a unique idea of self-levitating journal bearing are presented in this paper. the idea represents a radical departure from the current bearing technology. it utilisesacoustic levitation, which relies on the sound energy radiated by an object supporting a load. acoustic levitation has been demonstrated to support loads of up to 10 kg. in order to support a load theacoustic wave emitted by the radiating...
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Some fundamental aspects of self-levitating sliding contact bearings and their practical implementations
PublicationIn this study, fundamental aspects and mechanisms of acoustic levitation together with governing equations are presented first. Then, the acoustic levitation phenomenon is considered as a new way to design air suspension systems capable of self-levitation. A particular emphasis is laid on journal bearings and their specific geometrical configuration. A practical feasibility of using acoustic levitation to separate contacting surfaces...
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Special Issue on Sliding Contact Bearings
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Application of the fluid–structure interaction technique for the analysis of hydrodynamic lubrication problems
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Evaluation of water turbine hydrodynamic thrust bearing performance on the basis of thermoelastohydrodynamic calculations and operational data
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Simulation of large thrust-bearing performance at transient states, warm and cold start-up
PublicationThe start-up of a large hydrodynamic thrust bearing of a vertical hydrogenerator is one of the most critical situations during the lifetime of a bearing. Hydrodynamic load capacity is low due to low speed and higher thermal deformations of the pad. A new approach to the simulation of a hydrodynamic bearing is shown in this article. A combination of finite elements method and computational fluid dynamics is used to perform the transient...
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Application of the fluid–structure interaction technique for the analysis of hydrodynamic lubrication problems.
PublicationFluid–structure interaction technique seems to be one of the most promising possibilities for theoretical analysis of lubrication problems. It allows coupling of different physical fields in one computational task, taking into account the interaction between them. In this article, two sets of fluid–structure interaction analyses focusing on the bearing performance evaluation are presented. One analysis was applied to a water-lubricated...
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Experimental research on marine oil-lubricated stern tube bearing
PublicationBearings of propeller shafts are very crucial elements of the propulsion system of each of the ships. The safety of shipping depends on their durability and reliability. The new legal restrictions mean that today we are looking for environmentally friendly solutions. That is why water-lubricated bearings are becoming more and more popular. So, will oil-lubricated shaft bearings belong to the past? The bearing with a white metal...
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Large hydrodynamic thrust bearing: Comparison of the calculations and measurements
PublicationHydrodynamic thrust bearings, used to carry axial loads in heavily loaded shafts of water power plants hydro turbines, can reach outer diameters even exceeding 5 m. In such large objects scale effect could be observed. According to this, allowable bearing specific load assuring safe operation of the bearings has to be decreased, which increases thrust bearing dimensions. This effect is caused by excessive thermal deflections of...
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Comparison of the characteristics of journal bearings determined according to ISO 7902:2020 and obtained by other methods
PublicationThe article presents selected characteristics of journal bearings calculated with the use of various methods and compared to the results obtained with application of the basic bearing characteristics calculation procedure, as described in the ISO 7902:2020 standard. Additionally, the presented calculation results were compared with the parameters measured during experimental tests of the sliding bearings, working under loads and...
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The effect of random surface topography height on fretting in dry gross slip conditions
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The influence of antiwear additive concentration on the tribological behaviour of a-C:H:W/steel tribosystem
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Characterization and properties of low-friction, multilayered Cr-doped diamond-like carbon coatings prepared by pulse biased filtered cathodic arc deposition
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The rolling contact fatigue of WC/C-coated spur gears
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Wojciech Litwin dr hab. inż.
People1992÷1996 - study on Mechanical Department at Gdansk University of Technology1996 – employed in the Faculty of Ocean Engineering and Ship Technology at the Gdansk University of Technology2004 – PhD2014 – habilitation2016 - vice dean for science at Faculty of Ocean EngineeringHe participated in a number of designing and research programs connected with water lubricated bearings, solar technology and modern ship propulsion. Since...
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Michał Wasilczuk prof. dr hab. inż.
PeopleMichał Wasilczuk received his M.Sc. (1986), Ph.D. (1994) and D.Sc. (2004) from the Gdansk University of Technology. In 2016 was nominated Professor Currently he is a Full Professor and Head of the Department of Machine Design and Automotive Engineering at the Faculty of Mechanical Engineers at GUT Bearing systems and tribology are the main fields of his scientific and engineering interest - starting from the Ph.D. devoted to...
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Scientific research in the Department of Machine Design and Automotive Engineering
PublicationShort descriptions of various research subjects taken up at the Department of Machine Design and Automotive Engineering are included in the paper. The subjects cover a wide range of bearing systems and tribology research and the research on tires and road surfaces. A third field of activity is biomedical engineering – with the attempts to improve methods of modelling biological materials in FEM calculations. The Department has...
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Tadeusz Stolarski prof. dr hab. inż.
People