Wyniki wyszukiwania - Biblioteka Nauki

1

A Comparison of Wear Properties of Water Lubricated NBR and PTFE Sliding Bearings

100%

Piątkowska E.

Tribologia

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2019

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tom nr 1

29--35

EN

The excessive wear of a journal shaft can be caused by many factors, for example, working conditions (e.g., temperaturę, slip speed, the type of lubricant), pressure, the type of material used on the bearings and shafts and their roughness, as well as contamination remaining in the system. This paper presents the roughness profiles co-operating with a rubber (NBR) and polytetrafluoroethylene (PTFE) bushes. The conditions of cooperation between the two materials tested in the sliding combination with the stainless steel journal were the same in each pair of bearings (PV); therefore, the comparison of their wear depends only on the material properties of the bush and the deformation of the journal shaft caused by the bending moment. To assess the size of the journal shaft, they were tested using a profilograph. In addition to the journal shaft, bearings were also evaluated, the wear level of which was noticed without the use of specialized equipment.

PL

Nadmierne zużycie czopa wału okrętowego może być spowodowane wieloma czynnikami, np. warunkami pracy (temperatura, prędkość poślizgu, naciski, rodzaj czynnika smarnego), rodzajem materiału zastosowanego na panwie łożysk i czopy wałów oraz ich chropowatością, a także zanieczyszczeniami dostającymi się do układu. W niniejszym artykule przedstawione zostały profile chropowatości czopa wału okrętowego pracującego w panwi wykonanej z gumy (NBR) oraz z politetrafluoroetylenu (PTFE). Warunki współpracy obu badanych materiałów w skojarzeniu ślizgowym z nierdzewnym czopem były jednakowe w każdej parze łożysk (PV), dlatego też porównanie stopnia ich zużycia zależy jedynie od własności materiału panwi oraz deformacji czopa wywołanej momentem zginającym. W celu oceny wielkości zużycia czopów zostały one poddane badaniu za pomocą profilografometru. Poza czopem wału ocenie poddane zostały również panwie łożysk, których stopień zużycia dostrzegalny był bez użycia specjalistycznego sprzętu.

2

Influence of solid particle contamination on the wear process in water lubricated marine strut bearings with NBR and PTFE bushes

100%

Piątkowska E.

Polish Maritime Research

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2021

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tom nr 4

167--178

EN

This 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 of slide bearing. The amount of wear was checked by means of geometric structure measurements on the journals, namely, roughness profile measurements using both a contact profilometer and an optical microscope. The obtained results enabled correlations between the material comprising the sliding sleeve, roughness of the journals and contamination inside the water-lubricated slide bearings.

3

Selected problems of experimental testing marine stern tube bearings

51%

Barszczewska A. , Piątkowska E. , Litwin W.

Polish Maritime Research

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2019

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tom nr 2

142--154

EN

This paper presents typical methods for conducting experimental tests on main shaft slide bearings. There are described their possible testing capabilities , advantages , drawbacks and limitations. Various testing methods were analyzed to find a solution able of providing a wide range of possible investigations at possibly acceptable limitations.

4

Influence of lubrication water contamination by solid particles of mineral origin on marine strut propeller shafts bearings of ships

38%

Litwin W. , Barszczewska A. , Piątkowska E. , Szwoch I. , Matuszewski L. , Kahsin M.

Polish Maritime Research

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2024

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tom nr 4

187--196

EN

The stern tube or strat bearings are key important component for safety of shipping. Modern global regulations required a low as possible negative impact on environment including lubricants leaking to the sea. The ship owners are looking for reliable and durable solutions. The costs of each ship components are carefully studied. The water lubricated bearings for ship propeller shafts are an environmentally friendly solution. That is the reason why water lubrication is an interesting option to consider. Because simplicity of the ship design is expected the open lubricating system with only one seal module, when sea water is a lubricant is often recommended by manufacturer. This research was inspired by a series of failures or premature excessive wear of the propeller shaft strut bearings of real ships. The experimental tests were conducted in the laboratory on custom designed and build test-rig. The large group of tested bearings was delivered by certified manufacturers. The results of long time wear tests clearly prove that the cause of this premature wear was abrasive wear resulting from water contamination with solid particles of mineral origin. The range of the wear strongly depends on bearing bush materials and bearing interspace geometry. The wear was low for bearings with elastic bushes especially when hydrodynamic phenomena takes place. The general conclusion is that water lubrication is an interesting option to consider when design of the ship is discussed. The simplicity resulting an attractive price, low maintenance costs and proven durability and reliability of some bearings materials cause that this technology is becoming popular and often applied.