Filtry
wszystkich: 5015
-
Katalog
- Publikacje 3762 wyników po odfiltrowaniu
- Czasopisma 282 wyników po odfiltrowaniu
- Konferencje 152 wyników po odfiltrowaniu
- Osoby 267 wyników po odfiltrowaniu
- Projekty 5 wyników po odfiltrowaniu
- Zespoły Badawcze 1 wyników po odfiltrowaniu
- Kursy Online 113 wyników po odfiltrowaniu
- Wydarzenia 6 wyników po odfiltrowaniu
- Dane Badawcze 427 wyników po odfiltrowaniu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: HYDRODYNAMIC BEARING, OIL GROOVE, BEARING CLEARANCE, SHAFT, BEVELING OF THE SHAFT, COMPUTER SIMULATION
-
INFLUENCE OF SOLID PARTICLE CONTAMINATION ON THE WEAR PROCESS IN WATER LUBRICATED MARINE STRUT BEARINGS WITH NBR AND PTFE BUSHES
PublikacjaThis paper reports on a study of the influence of solid particle contamination on the wear process in water-lubricated slide bearings (steel-acrylonitrile-butadiene rubber (NBR) and steel- polytetrafluoroethylene (PTFE)). To compare the wear of the shaft journal and bushes (NBR and PTFE) when lubricated with fresh water and contaminated water, an experiment was carried out to identify key factors that influence the state of wear...
-
Wojciech Litwin dr hab. inż.
Osoby1992÷1996 – Studia na Wydziale Mechanicznym Politechniki Gdańskiej1996 – Zatrudniony na Wydziale Oceanotechniki i Okrętownictwa PG2004 – Obrona pracy doktorskiej2014 – obrona rozprawy habilitacyjnej2012 – obejmuje funkcję prodziekan ds. Nauki na Wydziale Oceanotechniki i OkrętownictwaUczestniczył w wielu projektach badawczych oraz pracach zleconych przez przemysł związanych z łożyskowaniem ślizgowym wałów głównych oraz niekonwencjonalnymi...
-
Polymer journal bearings behaviour research under limited lubrication and cooling conditions conducted on high torque test rig
PublikacjaPolymer journal bearings are frequently used as a water-lubricated bearings of small marine units’ propeller shafts . Choice of these bearings is based on their simple construction and relatively low purchase and maintenance costs. Although properly designed and installed water lubricated bearings may well last for over a decade, rapid wear or failure of these bearings can be observed...
-
Direct design of Controlled Modulus Columns (CMC) based on in-situ testing
PublikacjaIn this paper, the serviceability limit state and bearing capacity of tension screw displacement piles were analyzed using the results of static pile load tests, carried out on the test plot near the Elbląg city, and field, and laboratory tests. The paper presents the methodology of determining the pile load-settlement curve using different types of t-z transfer functions. The new method of constructing the pile load-settlement...
-
Water-Lubricated Journal Bearings Marine Applications, Design, and Operational Problems and Solutions
PublikacjaWater-Lubricated Journal Bearings: Marine Applications, Design, and Operational Problems and Solutions provides cutting-edge design solutions, common problems and methods for avoiding them, and material selection considerations for the use of water-lubricated journal bearings in marine environments. These bearings have many advantages, including the absence of the potential for oil contamination. They are also sensitive, and their...
-
Air journal bearing utilizing near-field acoustic levitation: stationary shaft case
PublikacjaResults 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...
-
Comparative wear test of journal sliding bearings with sintered bronze and Babbitt alloy bushes lubricated by environmentally acceptable/adapted lubricants (EAL)
PublikacjaA 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...
-
Pile Model Tests Using Strain Gauge Technology
PublikacjaOrdinary pile bearing capacity tests are usually carried out to determine the relationship between load and displacement of pile head. The measurement system required in such tests consists of force transducer and three or four displacement gauges. The whole system is installed at the pile head above the ground level. This approach, however, does not give us complete information about the pile-soil interaction. We can only determine...
-
Analysis of the instantaneous power signal for bearing diagnostics -bearing damaged
Dane BadawczeThe attached dataset contains the measurement results of the instantaneous values of current and voltage, recorded during the diagnostics of a damaged bearing. Bearing diagnostics can be carried out based on the method, which relies on the measurement and analysis of the variability of the signal instantaneous power, defined as the product of instantaneous...
-
Analysis of the instantaneous power signal for bearing diagnostics - bearing undamaged
Dane BadawczeThe attached dataset contains the measurement results of the instantaneous values of current and voltage, recorded during the diagnostics of an undamaged bearing. Bearing diagnostics can be carried out based on the method, which relies on the measurement and analysis of the variability of the signal instantaneous power, defined as the product of instantaneous...
-
ANALYSIS OF THE LOAD-CARRYING CAPACITY OF A HYDRODYNAMIC WATER-LUBRICATED BEARING IN A HYDROELECTRIC POwER PLANT
PublikacjaThe paper presents an analysis of the load-carrying capacity of a historic hydrodynamic water-lubricated radial bearing of an unconventional segment design installed in the Braniewo Hydroelectric Power Plant. The aim of the calculations was to determine whether the bearing operates in the conditions of hydrodynamic or mixed lubrication, as well as to establish the optimal geometry of the axial grooves allowing for the highest load-carrying...
-
Influence of Bearing Bush Geometry on Properties of Water Lubricated Marine Main Shaft Bearings
PublikacjaW pracy przedstawiono wpływ geometrii smarowanego wodą, okrętowego łożyska ślizgowego wału głównego na jego własności hydrodynamiczne.Wykazano, że wielkość luzu łożyskowego, położenie oraz liczba rowków smarnych mają znaczący wpływ na nośnosć łożyska.
-
Instantaneous power signal measurements for bearing diagnostics
Dane BadawczeBearing diagnostics can be carried out based on the method, which relies on the measurement and analysis of the variability of the signal instantaneous power, defined as the product of instantaneous current and voltage power supplied to the engines. Bearing damage causes the appearance of deformations, which are in the form of additional harmonic components...
-
Assessment of possible application of water lubricated sintered brass slide bearing for marine propeller shaft
PublikacjaW artykule przedstawiono wyniki badań eksperymentalnych smarowanego wodą łożyska poprzecznego z panwią wykonaną ze spieku brązu.Przedstawiono wyniki pomiarów rozkładu ciśnienia w filmie smarnym, trajektorie osi wału oraz oporów ruchu.Przeprowadzono ocenę przydatności tego typu łożyska do łożyskowania okrętowych wałów śrubowych.
-
New Generation of Water lubricated Foil bearing - Numerical Models and Experimental Verification
PublikacjaIn the paper a new idea of foil water lubricated bearing and methodology of hydrodynamic characteristics calculations is presented. To assesses the theoretical characteristics of these bearings two different computer models were built. First is structural model coupled with fluid model. It takes into account: fluid flow in the deformed fluid gap, specific design of bearing support and friction in bearing support. The second is...
-
Optimisation of turbine shaft heating process under steam turbine run-up conditions
PublikacjaAn important operational task for thermal turbines during run-up and run-down is to keep the stresses in the structural elements at a right level. This applies not only to their instantaneous values, but also to the impact of them on the engine lifetime. The turbine shaft is a particularly important element. The distribution of stresses depends on geometric characteristics of the shaft and its specific locations. This means a groove manufactured...
-
Effect of manufacturing errors of the pad sliding surface on the performance of the hydrodynamic thrust bearing
PublikacjaIn 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...
-
ENERGY ANALYSIS OF THE PROPULSION SHAFT FATIGUE PROCESS IN A ROTATING MECHANICAL SYSTEM PART II IDENTIFICATION STUDIES – DEVELOPING THE FATIGUE DURABILITY MODEL OF A DRIVE SHAFT
PublikacjaThe article presents a continuation of research carried out concerning identification of energy consequences of mechanical fatigue within a propeller shaft in a rotating mechanical system, while working under conditions of the loss of the required alignment of shaft lines. Experimental research was carried out on a physical model reflecting a full-sized real object: i.e., the propulsion system of the ship. It is proven, by means...
-
Diagnostics of the drive shaft bearing based on vibrations in the high-frequency range as a part of the vehicle's self-diagnostic system
Publikacja -
Mathematical Modelling of Drive System with an Elastic Coupling Based on Formal Analogy between the Transmission Shaft and the Electric Transmission Line
PublikacjaIn the paper, the kinematic structure of the transmission shaft between the driving motor and the working mechanism is studied. The analysis is based on electrical and mechanical similarities. The equivalent circuits, typical for electrical systems, are defined for the transmission shaft concerned. Modelling of the transmission shaft based on a formal analogy between the transmission shaft and the electric transmission line is...
-
ENERGY ANALYSIS OF PROPULSION SHAFT FATIGUE PROCESS IN ROTATING MECHANICAL SYSTEM PART I TESTING SIGNIFICANCE OF INFLUENCE OF SHAFT MATERIAL FATIGUE EXCITATION PARAMETERS
PublikacjaThe article discusses the problem of mathematical modelling of energy conversion processes in a rotating mechanical system for the purpose of identifying fatigue states of propulsion shafts in this system. A simplified physical model of the analysed system, constructed in an appropriate scale, has made the basis for the experimental research. The research programme took into consideration mechanical fatigue excitation of the model...
-
Hydrodynamic pressure in micro-and nano bearing gap
Publikacja.
-
Influence of Collar Deformations on Hydrodynamic Thrust Bearing Performance
Publikacja -
Hydrodynamic journal bearing - ''Y'' particularly for steam turbines.
PublikacjaW artykule przedstawiono koncepcję i zasadę działania nowego, ślizgoweo łożyska poprzecznego typu ''Y''. Przedstawiono wady i zalety nowego rozwiązania. Porównano charakterystyki dynamiczne i statyczne klasycznego łożyska cytrynowego (soczewkowego) z nowym łożyskiem ''Y''.Podano przykładowe wdrożenia i ich efekty.
-
A method to assess transverse vibration energy of ship propeller shaft for diagnostic purposes
PublikacjaThe article discusses a key problem of ship propulsion system vibration diagnostics, which concerns assessing this part of mechanical energy transmitted from the main engine to the ship propeller which is dissipated due to propeller shaft vibration. A simplified calculation model is proposed which allows the total energy of the generated torsional vibration to be assessed from the shaft deflection amplitude measured at the mind-span...
-
Prospects of Decreasing Power Losses in a Hydrostatic Thrust Bearing
PublikacjaIn numerous machines, axial load is carried by tilting pad thrust bearings known since the beginning of 20th century. These bearings are commonly bath lubricated, which is simple, does not require any additional pumps, and, due to this, such systems are highly reliable. In a contemporary technology, however, minimization of friction losses became an important goal of machinery improvement. Calculations based on elementary rules...
-
Running performance of an aerodynamic journal bearing with squeeze film effect
PublikacjaResults of theoretical and experimental studies concerning the performance of an aerodynamic journal bearing of which running is assisted by squeeze film ultrasonic levitation (SFUL) are presented in this paper. The SFUL mechanism not only can separate journal from the bearing at the start and stop phases of operation but also can significantly contribute to the dynamic stability of the bearing when it runs at speed. Computer calculations...
-
Acoustic journal bearing - A search for adequate configuration
PublikacjaClassical 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....
-
Problems of analytical determination of journal bearing bush fatigue strength estimates
PublikacjaProblems connected with determination of stress distribution in sliding layer of thinwalled bearing bushes, investigated in bearing fatigue test rigs, have been presented. Using an example of plain bearings tested in the fatigue machine SMOK (built at the Gdask University of Technology) problems with obtaining a convergence of iterative procedure for determining the fatigue strength estimators of bearing alloy surface layer are...
-
The concept of estimation of elevator shaft control measurement results in the local 3D coordinate system.
PublikacjaGeodetic control measurements play an important part because they provide information about the current state of repair of the construction, which has a direct impact on the safety assessment of its exploitation. Authors in this paper have focused on control measurements of the elevator shaft. The article discusses the problem of determining the deviation of elevator shaft walls from the vertical plane in the local 3D coordinate...
-
Improvement of Thrust Bearing Calculation Considering the Convectional Heating within the Space between the Pads
PublikacjaA modern thrust bearing tool is used to estimate the behavior of tilting pad thrust bearings not only in the oil film between pad and rotating collar, but also in the space between the pads. The oil flow in the space significantly influences the oil film inlet temperature and the heating of pad and collar. For that reason, it is necessary to define an oil mixing model for the space between the pads. In the bearing tool, the solutions...
-
THE INFLUENCE OF HOUSING ARRANGEMENT AND INTERFERENCE ON PRELOAD AND THEORETICAL LIFETIME OF A SYSTEM OF TAPER ROLLER BEARINGS OF A HIGH SPEED SHAFT OF A WIND TURBINE GEARBOX
PublikacjaA system of two taper roller bearings can carry loads with a high ratio of axial load to radial load. Such a system was proposed for a wind turbine gearbox following the poor durability of original bearing design with the aim of increasing durability. Because of size limits, a proposed system is composed of two different taper roller bearings. Standard manufacturers’ catalogues do not provide information on recommended preload...
-
Effect of Coating Material Properties on Tilting-pad Thrust Bearing Performance
PublikacjaPolymer lined tilting-pad bearings demonstrate many advantages over traditional bearing systems. Bearings with a polymer layer in comparison with a babbitted layer show, for example: lower value of friction coefficient (important during start/stops), higher fatigue strength of the coating, better distribution of the load on individual pads due to lower elasticity of the polymers, wider range of operational temperatures or the ability...
-
OPERATION OF TWO-SHAFT GAS TURBINE IN THE RANGE OF OPEN ANTI-SURGE VALVE
PublikacjaThis paper presents experimental tests of full-scale two-shaft gas turbine in the range of open anti-surge valve (ASV). The tests were carried out in a laboratory gas- turbine test stand belonging to Department of Automation and Power Engineering , Faculty of Ocean Engineering and Ship Technology , Gdańsk University of Technology. The tests covered the start-up and low load operation of the turbine set in the range of open...
-
Biocompatibility and bioactivity of bearing loaded metallic implants
PublikacjaPresentation of developed titanium alloy base composite materials possessing better biocompatibility, longer lifetime and bioactivity behavior for bearing loaded implants, e.g. hip joint and knee joint endoproshtesis.
-
Journal of Essential Oil Bearing Plants
Czasopisma -
Search for the most useful geometry of an acoustic journal bearing
PublikacjaComputer simulations of a number of journal bearing’s geometries utilising acoustic levitation were carried out. The choice of the best geometry depended on the ability of a deformed shape, created by piezo-electric elements, to facilitate squeeze film ultrasonic levitation, and also to create three evenly distributed diverging aerodynamic gaps. Deformations of analysed variants of the bearing’s shape were generated by numerical...
-
Diagnosis of bearing damage in induction motors by instantaneous power analysis
PublikacjaResearch of the machine with simulated bearing damages has been carried out, where variable load torque, simulating bearing damage, was introduced. The results show that components which can be used for bearings diagnosis appear in the spectrum of the product of current and supply voltage instantaneous values. These components are easier to identify than the components of current spectrum, which have been used so far in diagnostic...
-
Some problems of slide bearing material fatigue evaluation.
PublikacjaA slide bearing alloy resistance against fatigue failures have been investigated for three different lubricants, different heat loadings and different stress ratio κ values. The research methods and data handling procedures for determination of particular parameter effects on fatigue strength have been described and analysed for experiments that were set and performed in laboratory tester SKMR-2. Main and interaction effects of...
-
Improving the accuracy of bearing in active sonar with cylindrical array using spectrum estimation.
PublikacjaThe articles presents a method for improving the accuracy of bearing in multibeam sonar with a cylindrical array. Based on a known spatial spectrum estimation technique, the method has been successfully used in linear array systems. Its accuracy of bearing is satisfactory and ensures a relatively low computational effort. The article discusses certain simplifications and assumptions to adapt the spatial spectrum estimation technique...
-
IN VITRO PROPAGATION OF RHODODENDRON TOMENTOSUM - AN ENDANGERED ESSENTIAL OIL BEARING PLANT FROM PEATLAND
PublikacjaRhododendron tomentosum Harmaja (formerly Ledum palustre L.) is a medicinal peat bog plant native to northern Europe, Asia and North America. This plant has a distinctive aroma thanks to the presence of essential oil, to which it also owes its anti-inflammatory, analgesic, antimicrobial and insecticidal properties. However, in Europe R. tomentosum is classified as an endangered species, mainly due to degradation of peatlands. In...
-
Impact of Spatial Noise Correlation on Bearing Accuracy in DIFAR Systems
PublikacjaDIFAR type underwater passive systems are one of the more commonly used tools for detecting submarines. At the design stage, which usually uses computer simulations, it is necessary to generate acoustic noise of the sea. It has been shown that correlating noise significantly reduces these errors compared to the assumption that noise is uncorrelated. In addition, bearing errors have been shown to be the same in systems with a commonly...
-
ENERGY ANALYSIS OF THE PROPULSION SHAFT FATIGUE PROCESS IN A ROTATING MECHANICAL SYSTEM PART III DIMENSIONAL ANALYSIS
PublikacjaThis article presents the third and last part of the problem of diagnosing the fatigue of marine propulsion shafts in terms of energy with the use of the action function, undertaken by the authors. Even the most perfect physical models of real objects, observed under laboratory conditions and developed based on the results of their research, cannot be useful in diagnostics without properly transferring the obtained results to the...
-
Improvement of the thrust bearing calculation considering the convectional heating within the space between the pads
PublikacjaA modern thrust bearing calculation tool should consider not only the oil film between pad and rotating collar but also the space between the pads. The oil flow in the space has a significant influence on the oil film inlet temperature, the convectional cooling of pad and collar and should be included in the bearing calculation methods. The authors use a tool developed at Clausthal University of Technology in cooperation with the...
-
Numerical estimation of the pile toe and shaft unit resistances during the installation process in sands
PublikacjaNumerical simulations of a pile jacking were carried out. A Coupled Eulerian–Lagrangian (CEL) formulation was used to treat with large deformation problems. An Abaqus, a commercial Finite Element Method software suit, was used as a computing environment. The Mohr–Coulomb constitutive model was applied and the Coulomb model of friction was used to describe pile-soil interaction. Calculations were made for three different pile diameters....
-
The Possibilities of Improving the Fatigue Durabilityof the Ship Propeller Shaft by Burnishing Process
PublikacjaHeavily loaded structural elements operating in a corrosive environment are usuallyquickly destroyed. An example of such an element is a ship propeller operating in a seawaterenvironment. This research presents a fatigue resistance test performed on elements operating inseawater. Different processing parameters applied on the samples in particular were compared withthe specimens whose surface had been burnished differently and...
-
Investigation of the IC engine lubricating oil effects on journal bearing life
PublikacjaPrzedstawiono wyniki modelowych badań eksperymentalnych wytrzymałości zmęczeniowej warstwy ślizgowej łożysk silników spalinowych. W szczególności oceniono wpływ właściwości oleju smarowego na tę wytrzymałość.
-
Problems of Flaking in Strengthening Shaft Burnishing
PublikacjaThe article presents the results of testing the surface condition of shafts manufactured by a strengthening rolling burnishing process. The shafts with a hardness about 220 HB were burnished with a roller with different force. Researches were carried out with particular attention to the structure of the outflowing material in the tool zone during burnishing process. The article presents the results of the examinations of burnished...
-
Bearing capacity of the working platform with kinematic method
PublikacjaBearing capacity of the working platform for heavy tracks was analysed using Distinct Layout Optimization (DLO) method. The platform layer constructed from cohesionless soils is resting on weak cohesive subgrade. Different thickness of the platform, its effective angle of internal friction and undrained shear strength of the soft soil were taken into consideration. Kinematic method permits different failure mechanisms to be analyzed....
-
Biocompatibility and Bioactivity of Load-Bearing Metallic Implants
PublikacjaThe main objective of here presented research is to develop the titanium (Ti) alloy base composite materials possessing better biocompatibility, longer lifetime and bioactivity behaviour for load-bearing implants, e.g. hip joint and knee joint endoprosthesis. The development of such materials is performed through: modeling the material behaviour in biological environment in long time and developing of new procedures for such evaluation;...