Endre søk
Begrens søket
1 - 20 of 20
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Glavatskih, Sergei
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    McCarthy, Donald
    Hydrodynamic bearings with improved performance and reliability : Part I: Influence of pad surface material2003Rapport (Annet vitenskapelig)
    Abstract [en]

    Study of the influence on performance characteristics of employing a compliant facing material (PTFE) on hydrodynamic fluid film thrust bearings. Comparison is made between plain babbitt and PTFE facing materials

  • 2.
    Glavatskih, Sergei
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    McCarthy, Donald
    Hydrodynamic bearings with improved performance and reliability : Part II: Influence of pad surface texturing2003Rapport (Annet vitenskapelig)
    Abstract [en]

    Study of the influence on performance characteristics, including oil film thickness, of employing an etched pattern on the babbitt facing of hydrodynamic fluid film thrust bearings. Comparison is made between plain babbitt and etched babbitt facing material.

  • 3.
    Glavatskih, Sergei
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Mccarthy, Donald
    Sherrington, I.
    Jost Institute for Tribotechnology, Department of Technology, University of Central Lancashire, Preston.
    Hydrodynamic performance of a thrust bearing with micropatterned pads2005Inngår i: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 48, nr 4, s. 492-498Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The primary objective of this study was to investigate the influence of surface texturing on hydrodynamic lubrication of tilting-pad thrust bearings in terms of bearing power loss, operating temperature, and oil-film thickness. For this purpose, the working faces of six thrust pads from a 228.6-mm-outer-diameter bearing were textured. The textured surface consisted of a system of crossing channels of less than 10 μm in depth. Tests were conducted with a VG68 mineral turbine oil supplied to the bearings at a constant temperature of 50°C and flow rate of 15 L/min. The following parameters were measured: frictional torque, pad and collar temperatures, oil-film thickness, and pressure profiles along two circumferential lines. No significant change in collar and pad temperature could be observed when the patterned bearing was used. However, the textured bearing showed a tendency to exhibit lower power loss especially when an optimum oil flow supply rate was used. At the same time, inlet and outlet film thicknesses for the patterned bearing showed larger values than those obtained during tests on the plain babbitt pads.

  • 4.
    Glavatskih, Sergei
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Mccarthy, Donald
    Sherrington, Ian
    Department of Engineering and Product Design, University of Central Lancashire, Preston.
    Further transient test results for a pivoted-pad thrust bearing2004Inngår i: Transient processes in tribology: proceedings of the 30th Leeds-Lyon Symposium on Tribology held at INSA de Lyon Villeurbanne, France, 2nd-5th September 2003 / [ed] Gérard Dalmaz, Amsterdam: Elsevier, 2004, s. 301-312Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Evolution of friction torque in a pivoted-pad thrust pad bearing, as well as collar and shaft temperatures and pressure profiles in transient conditions, have been investigated in [1]. The present paper reports further transient test results for the same thrust bearing with an outer diameter of 228.6mm and 60% offset pivoted pads, operated in fully flooded mode. In this study, a complete set of bearing main performance parameters, including bearing pad and collar temperatures, oil film thickness and friction torque are obtained by means of a high-speed data acquisition system. Evolution of these parameters as a result of sudden variations in rotational speed and load are presented and analysed. Results are generalised in terms of Fourier number and compared with published numerical data

  • 5.
    Markin, D.
    et al.
    Luleå tekniska universitet.
    McCarthy, Donald
    Glavatskikh, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    A FEM approach to simulation of tilting-pad thrust bearing assemblies2003Inngår i: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 36, nr 11, s. 807-814Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Finite-element method (FEM) modelling is applied to analysis of the performance of hydrodynamic tilting-pad thrust bearing assemblies. A 3D model of the bearing assembly that includes the bearing pad and shaft is used to assess the influence of operating conditions on bearing parameters such as temperature and oil film distributions across the pads. The model is first applied to the investigation of a spherically pivoted-pad. Through comparison with results from experiments carried out on just such a bearing, good correlation between the model and experimental results is found for maximum oil film temperature, pressure distribution and thickness. The model is then applied to the examination of a bearing having spring-supported babbitt pads. The effect of different oil types on a spring-supported thrust bearing is analysed. Further application of the model to investigate the same spring-supported pad, this time with a resilient surface coating, is discussed.

  • 6. McCarthy, Donald
    Lubrication of sliding bearings for hydropower applications2005Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The term "sliding bearing" refers to types of bearing where two conformal surfaces (usually the stationary bearing and a moving shaft) slide relative to one another with load distributed directly across the interface. A suitable lubricant may be employed to reduce the friction between these two surfaces. In "fluid film" bearings, this lubricant builds up a layer of sufficient thickness such that the two surfaces are completely separated. Examples include journal and thrust bearings and shaft bushings. Unlike ball or roller bearings which have a limited lifespan, sliding bearings have, at least in theory, an indefinite operational lifespan. As long as an oil film of sufficient thickness is maintained and contamination is avoided, the bearing may continue to do its job indefinitely. However, more and more onerous demands are being placed on such bearings and their associated methods of lubrication in order to maximise performance in terms of efficiency and load carrying capacity, for example in hydroelectricity generators and turbines. Given the sensitivity of operating any form of mechanical equipment in the vicinity of watercourses, often the source of drinking water for major population centres, the hydropower industry has a duty of responsibility in ensuring that as much as possible is done to minimise the risk of contamination of the water or damage to flora and fauna. Two aims - increased output, decreased environmental impact - are currently the major driving forces behind Research and Development in the hydroelectric power generation industry. Looking at these from a tribological (friction and lubrication) point of view, three areas of particular interest can be identified. These are: 1) How can the load carrying capacity of thrust bearings be increased whilst at the same time improving performance within existing dimensional constraints? 2) What is the influence on bearings of transient events (rapid changes in speed or loading) and what impact do they have on the machinery components? 3) How does the use of Environmentally Adapted Lubricants (as opposed to mineral oils) influence friction and wear etc, specifically with reference to shaft bushings, and what is the impact of fluid ageing (oxidation) on their performance? Each of these three points has been studied in the course of the work carried out for this thesis.

    Fulltekst (pdf)
    FULLTEXT01
  • 7.
    McCarthy, Donald
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Sliding bearings for hydropower applications: novel materials, surface texture and EALs2008Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Hydropower, the utilisation of water as a means of driving machinery, has been used for many centuries. Today, the great power of water is being harnessed to generate as much as 20% of worldwide electricity. The requirement for reliable and efficient electricity generation needs to be matched by environmental awareness on the part of the industry. Work carried out during the course of my doctoral studies at Luleå University of Technology has been aimed at addressing these demands by investigating means of improving sliding bearing performance through the use of environmentally adapted lubricants and the employment of novel materials and surface texturing to reduce friction. The term "sliding bearing" refers to a type of bearing where two surfaces (usually the stationary bearing and a moving shaft) slide relative to one another with load distributed directly across the interface. In hydrodynamic bearings, a lubricant layer is built up in the contact region such that the two surfaces are completely separated. Examples of these are hydrodynamic journal and thrust bearings. These types of bearing are major components in many large machines, including hydroelectric turbines. Their safe operation relies on the maintaining of sufficient oil film thickness. As long as this condition is met, the bearing could continue to do its job indefinitely. This is particularly important during transient operating conditions (i.e. rapid changes in load or speed) when oil films can momentarily become extremely thin. Such conditions have been examined for a tilting-pad thrust bearing to assess impact on operation. More and more onerous demands are being placed on such bearings and their associated methods of lubrication, e.g. increased frequency of start/stop of hydroelectric turbines. This means that new solutions are required to maximise their operational performance. One such solution attracting current attention is the employment of surface texturing. The impact of surface texturing on the performance of a tilting-pad thrust bearing has been studied in a series of tests in comparison with a plain Babbitt surface. These show a reduction in friction with the textured bearing. Film thickness is seen to be greater suggesting improved load-carrying capacity. Another possible option for improving operational performance is the use of new lubricants. Environmentally Adapted Lubricants (EALs) are produced from simple hydrocarbons meaning that the final product tends to consist of only a few different types of molecule. This also means that an EAL can be carefully tailored to a specific function. In several experimental investigations using such fluids in both thrust and journal bearings, it has been shown that minimum film thicknesses can be maintained using an EAL with lower viscosity grade than that of the mineral oil currently used. This has the added impact of reducing bearing power (friction) losses and lowering temperatures, all beneficial to bearing operation. Thicker film has been found for an EAL of identical viscosity grade to the mineral oil. Unlike mineral oils, which have been employed as lubricants for decades, little data is available for the long-term performance of EALs. This is of interest as their use has only recently begun to catch on in the power generation industry. A study of aged EALs in a tin bronze-steel contact, typical of what may be found in hydroelectric turbines, has shown continued satisfactory performance even at high acid number (high oxidation level), beyond the point where an oil would normally be changed out. The introduction of new materials provides a means of solving certain problems associated with machine operation and reliability. The use of PTFE as a bearing facing material is well established but little has been published about its performance in this application. A series of experiments have been performed to investigate the impact of employing such a facing on a tilting-pad thrust bearing. A thicker minimum film is found at the outlet edge of the pads in comparison with a babbit (white metal) faced bearing. Temperatures within the pad bulk material are seen to be lower as a result of the insulating effects of the polymer, thereby reducing the impact of thermal crowning. An investigation has also been performed with a range of PTFE composite materials to assess their suitability as a replacement for babbitt facing material in hydrodynamic journal bearings. The polymer composites have been shown to introduce clear benefits in comparison with pure PTFE and babbitt in terms of reduced wear and break-away friction at start-up.

    Fulltekst (pdf)
    FULLTEXT01
  • 8. McCarthy, Donald
    et al.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Assessment of polymer composites for hydrodynamic journal bearing applications2008Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Polymer composites are employed as facing materials in hydrodynamic bearings for their low friction and "compliant" properties which play an important role during machinery operation. In journal bearings, this low friction property can be of significant importance during start and stop cycles when insufficient oil is available to fully separate the surfaces in relative motion. Current work is aimed at determining a suitable material for use in hydrodynamic journal bearings. This study investigates friction and wear encountered during the transition from the stationary state to operational speed (acceleration) during initial start-up. This is examined for virgin PTFE together with a series of commercially available PTFE-based composites and a babbitt material in boundary / mixed lubrication conditions. Tests are performed using a standard laboratory block-on-ring test apparatus with a VG32 mineral oil.

    Fulltekst (pdf)
    FULLTEXT01
  • 9. McCarthy, Donald
    et al.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Assessment of polymer composites for hydrodynamic journal-bearing applications2009Inngår i: Lubrication Science, ISSN 0954-0075, E-ISSN 1557-6833, Vol. 21, nr 8, s. 331-341Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Polymer composites are used as facing materials in hydrodynamic bearings for their low friction and compliant properties, which play an important role during machinery operation. In journal bearings, this low friction property can be of significant importance during start and stop cycles when insufficient oil is available to fully separate the surfaces in relative motion. Current work is aimed at determining a suitable material for use in hydrodynamic journal bearings for applications in hydroelectric power plants. This study investigates friction and wear encountered during the transition from the stationary state to operational speed (acceleration) during initial start-up. This is examined for virgin poly-tetra-fluoro-ethylene (PTFE) together with a series of commercially available PTFE-based composites and a babbitt material in boundary/mixed lubrication conditions. Tests are performed using standard laboratory block-on-ring test apparatus with a VG32 mineral oil.

  • 10. McCarthy, Donald
    et al.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    "Break-away" friction for PTFE-based composites2008Inngår i: Lubricants, materials and lubrication engineering: 16th International Colloquium Tribology; January 15 - 17, 2008 in Stuttgart/Ostfildern, Germany / [ed] Wilfried J. Bartz, Ostfildern: Techn. Akad. Esslingen , 2008Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The use of polymer composites as facing materials in hydrodynamic thrust bearings gives performance benefits in terms of temperature distribution and friction losses. A study was carried out to investigate the break-away friction encountered during the transition phase (acceleration) under initial start-up from stationary state to full operational speed. This was examined for a series of commercially available PTFE-based composites. The lubricant used was a mineral oil. Best performance in terms of relative friction and wear was found for a carbon filled PTFE composite material. This is an abstract of a paper presented at the 16th International Colloquium Tribology Lubricants Materials and Lubrication Engineering (Stuttgart/Ostfildern, Germany 1/15-17/2008).

  • 11. McCarthy, Donald
    et al.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Byheden, A.
    Statoil Lubricants R&D.
    Hydrodynamic journal bearing performance using rapeseed base fluid lubricant2008Inngår i: Lubricants, materials and lubrication engineering: 16th International Colloquium Tribology; January 15 - 17, 2008 in Stuttgart/Ostfildern, Germany / [ed] Wilfried J. Bartz, Ostfildern: Techn. Akad. Esslingen , 2008Konferansepaper (Annet vitenskapelig)
  • 12. McCarthy, Donald
    et al.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Byheden, Åke
    Statoil Lubricants, Nynäshamn.
    Influence of oil type on the performance characteristics of a two axial groove journal bearing2008Inngår i: Proceedings of NORDTRIB 2008, 13th Nordic Symposium on Tribology: Scandic Rosendahl Hotel, Tampere, Finland, June 10 - 13, 2008 / [ed] Jaakko Kleemola; Arto Lehtovaara, Tampere: Tampere University of Technology, 2008Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The use of Environmentally Adapted Lubricants (EALs) is a subject of growing interest to industry as legislation increasingly demands the replacement of mineral oil lubricants. Vegetable based fluids are widely seen as providing lubricants from a renewable source as well as meeting demands for improved biodegradability. However, at present, utilisation of such fluids is limited due to their rapid oxidation. EALs produced from other base stocks (i.e. synthetic esters) have been shown to provide performance benefits in hydrodynamic thrust bearings. In the present study, a hydrodynamic journal bearing test rig has been employed to compare the performance of three EALs (a VG32 saturated ester, rapeseed base fluid and a Propylene Glycol Dioleate) relative to three mineral turbine oils (ISOVG32, ISOVG46 and ISOVG68) in the hydrodynamic regime. Results are given in terms of temperature, power loss and minimum film thickness. The impact of oil VI is also discussed.

    Fulltekst (pdf)
    FULLTEXT01
  • 13. McCarthy, Donald
    et al.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Byheden, Åke
    Statoil.
    Influence of oil type on the performance characteristics of a two-axial groove journal bearing2009Inngår i: Lubrication Science, ISSN 0954-0075, E-ISSN 1557-6833, Vol. 21, nr 9, s. 366-377Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The use of environmentally adapted lubricants (EALs) is a subject of growing interest to industry as legislation increasingly demands the replacement of mineral oil lubricants. Vegetable-based fluids are widely seen as providing lubricants from a renewable source, as well as meeting demands for improved biodegradability. However, at present, utilization of such fluids is limited due to their rapid oxidation. EALs produced from other base stocks (i.e. synthetic esters) have been shown to provide performance benefi ts in hydrodynamic thrust bearings. In the present study, a hydrodynamic journal bearing test rig has been employed to compare the performance of three EALs (a VG32 saturated ester, rapeseed base fluid and a propylene glycoldioleate) relative to three mineral turbine oils (ISOVG32, ISOVG46 and ISOVG68) in the hydrodynamic regime. Results are given in terms of temperature, power loss and minimum fi lm thickness. The impact of oil viscosity index is also discussed.

  • 14. Mccarthy, Donald
    et al.
    Glavatskih, Sergei
    Kassfeldt, Elisabet
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Pach, Mayte
    Statoil Lubricants R&D, Nynäshamn.
    Byheden, Åke
    Statoil Lubricants R&D, Nynäshamn.
    Norrby, Thomas
    Aged environmentally adapted lubricants: Part II: Performance evaluation in boundary lubricated contacts2006Inngår i: Automotive and industrial lubrication: 15th International Colloquium Tribology, January 17 - 19, 2006 ; [book of synopses 2006] / [ed] Wilfried J. Bartz, Ostfildern: Techn. Akad. Esslingen , 2006, s. 140-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Experiments are conducted to compare the performance of fresh and aged samples of three oils in a boundary lubricated contact. These oils are Oil A (a commercially available unsaturated synthetic ester based hydraulic fluid (ISOVG32)), Oil B (a mineral based turbine oil (ISOVG68), and Oil C (a saturated synthetic ester based lubricating fluid (ISOVG46)). Tests are performed using a tin-bronze on steel contact in a pin-on-disc apparatus. Results from these tests provide data relating to friction and wear and their coupling to the aging of the fluids. No evidence of any significant deterioration of lubricant performance is observed for any of the fluids tested. This is an abstract of a paper presented at the 15th International Colloquium Tribology - Automotive and Industrial Lubrication (Ostfildern, Germany 1/17-19/2006).

  • 15. McCarthy, Donald
    et al.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Pach, M.
    Statoil Lubricants R&D.
    Dmitriev, A.
    Department of Applied Physics, Chalmers University of Technology.
    Performance evaluation for aged environmentally adapted lubricants in bronze-steel sliding contacts2008Inngår i: Journal of Synthetic Lubrication, ISSN 0265-6582, Vol. 25, nr 3, s. 115-129Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Environmentally adapted lubricants (EALs) are becoming of increasing interest to the industry as legislation demands the replacement of mineral oil lubricants. However, little or nothing is known about the infl uence of ageing on the performance of these fluids in mixed and boundary lubricated tribological contacts. In this study, samples of three fully formulated lubricating oils, both in their 'unaged' form and 'aged' by means of an oxidation process in the laboratory, were utilized in a detailed study whereby variations in relative lubrication performance were examined. Standard laboratory pin-on-disc equipment was utilized in order to allow comparisons to be made and the definition of conclusions for a sliding tin bronze on steel contact. This simulated the interaction between an oil-lubricated bronze bushing and steel shaft as found in the vane adjustment mechanism of a Kaplan turbine. X-ray photoelectron spectroscopy analysis was employed to assess the effect on surface layer structural chemistry. Results showed, for the specific application being investigated, that EALs continue to function well in terms of their friction and wear performance even at high acid numbers

  • 16. Mccarthy, Donald
    et al.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Sherrington, Ian
    Oil film thickness and temperature measurements in PTFE and Babbitt faced tilting-pad thrust bearings2006Inngår i: Proceedings of the 11th Nordic symposium on tribology: NORDTRIB 2004 : Tromsø, Harstad, Hurtigruten, [Bodø], Norway, June [1 - 5], 2004, 2006, s. 167-176Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The influence of pad facing material on hydrodynamic lubrication in tilting-pad thrust bearings is investigated in terms of pad and oil-film temperatures and thicknesses. Two tilting-pad thrust bearings are examined: one with babbitt pad facing, the other with a layer of PTFE-based composite material. Frictional torque, pad, collar, and oil-film temperatures and thicknesses are all monitored by means of a comprehensive array of sensors mounted in the bearing and shaft. A considerably smaller range of temperature is seen in the steel backing immediately below the surface material for the PTFE faced pads. Oil-film temperatures measured at the mid-point on the pad trailing edge show no significant difference between the two bearings. Oil-film thicknesses in the two bearings are seen to differ. At the leading edge, oil-film thickness is thinner for the PTFE pad than for babbitt. However, at the trailing edge the PTFE pad has the thicker film.

  • 17. Mccarthy, Donald
    et al.
    Glavatskikh, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Sherrington, I.
    University of Central Lancashire, Jost Institute for Tribotechnology, Department of Technology.
    Oil-film thickness and temperature measurements in PTFE and babbitt faced tilting-pad thrust bearings2005Inngår i: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 219, nr 3, s. 179-185Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The influence of pad facing material on hydrodynamic lubrication in tilting-pad thrust bearings is investigated in terms of pad and oil-film temperatures and thicknesses. Two tilting-pad thrust bearings are examined: one with babbitt pad facing, the other with a layer of PTFE-based composite material. Frictional torque, pad, collar, and oil-film temperatures and thicknesses are all monitored by means of a comprehensive array of sensors mounted in the bearing and shaft. A considerably smaller range of temperature is seen in the steel backing immediately below the surface material for the PTFE faced pads. Oil-film temperatures measured at the mid-point on the pad trailing edge show no significant difference between the two bearings. Oil-film thicknesses in the two bearings are seen to differ. At the leading edge, oil-film thickness is thinner for the PTFE pad than for babbitt. However, at the trailing edge the PTFE pad has the thicker film.

  • 18.
    Pach, Mayte
    et al.
    Statoil Lubricants R&D, Nynäshamn.
    Byheden, Åke
    Statoil Lubricants R&D, Nynäshamn.
    Norrby, Thomas
    Mccarthy, Donald
    Kassfeldt, Elisabet
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Glavatskih, Sergei
    Aged environmentally adapted lubricants: Part I: Techniques and procedures for accelerated ageing2006Inngår i: Automotive and industrial lubrication: 15th International Colloquium Tribology, January 17 - 19, 2006 ; [book of synopses 2006] / [ed] Wilfried J. Bartz, Ostfildern: Techn. Akad. Esslingen , 2006, s. 139-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The aging behavior of synthetic lubricants, in particular environmentally adapted lubricants esters, in comparison to mineral base oils, is studied. V Three fully commercially formulated lubricants were subjected to an oxidation process using a modified dry-Waterless Turbine Oil Oxidation Stability Test. The oils were: Oil A (hydraulic unsaturated ester with antioxidants and corrosion inhibitors), Oil B (turbine mineral oil with antioxidants and corrosion inhibitors), and Oil C (turbine saturated ester oil with antioxidants and corrosion inhibitors). This is an abstract of a paper presented at the 15th International Colloquium Tribology - Automotive and Industrial Lubrication (Ostfildern, Germany 1/17-19/2006).

  • 19.
    Ukonsaari, Jan
    et al.
    Vattenfall Research & Development.
    Kassfeldt, Elisabet
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    McCarthy, Donald
    Tribological study of boundary lubricated TiN-bronze bearing under slow intermittent motion using an environmentally adapted synthetic ester2008Inngår i: Tribologia : Finnish Journal of Tribology, ISSN 0780-2285, Vol. 27, nr 1, s. 19-33Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lubricated journal bearings operating at moderate temperatures under conditions of slow intermittent or oscillating motion are important components in many items of machinery. In this application, choosing a suitable lubricant is critical to prolonging the lifetime of the component. The choice of lubricant is often dependent on the material pairing between the bearing and shaft. In parallel with growing concern about the environment, the development of environmentally adapted lubricants (EALs), such as synthetic esters, is gradually gaining pace. Studies have shown the ability of synthetic esters to reduce friction and wear under boundary lubricated conditions, especially with low alloyed bronzes on hardened steel. This study deals with the investigation of three different shaft materials, i.e. hardened, DLC-coated or normal steel, for use with a tin-bronze journal bearing lubricated with a synthetic ester. Experiments using the journal bearing show encouraging friction and wear results with the synthetic ester lubricant in comparison to tests with a mineral oil under the same operating conditions. (16 refs.)

  • 20.
    Ukonsaari, Jan
    et al.
    Vattenfall Research & Development.
    McCarthy, Donald
    Prakash, Braham
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Hedström, Peter
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Tribological studies on an EAL lubricated bearing bronze - steel pair under reciprocating sliding conditions2008Inngår i: Tribologia : Finnish Journal of Tribology, ISSN 0780-2285, Vol. 27, nr 1, s. 3-18Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Boundary lubricated journal bearings are found in various applications involving oscillatory sliding conditions. Environmental adaptation of hydraulic systems includes the introduction of synthetic esters. These new environmentally adapted lubricants (EALs) have shown very good boundary lubrication performance but also condition sensitivity. This study examines an oil lubricated bronze pin on hardened steel configuration in a reciprocating friction and wear test machine. Three synthetic esters were tested with a 1 mm stroke length. Results were compared with those for a mineral oil. The tribological performance with synthetic ester lubricant can, under certain conditions, be very good. SEM-EDS and XRD surface sensitive studies indicate the formation of a soft, copper enriched outer contact layer. The layer's nature and contact mechanisms clearly affect the performance of the different lubricants. (17 refs.)

1 - 20 of 20
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf