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  • 1.
    Glavatskih, Sergei
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Hanahashi, Minoru
    Daido Metal Co., Inuyama.
    Kawaike, Kazuhiko
    Daido Metal Co., Inuyama.
    Byheden, Åke
    Statoil Lubricants, Nynäshamn.
    Norrby, Thomas
    Influence of oil type on tilting pad journal bearing thermal characteristics2009Inngår i: Proceedings of the World Tribology Congress 2009: Sunday 6th to Friday 11th, September, 2009, Kyoto, Japan, Tokyo: Japan Society of Tribologists , 2009, s. 6183-6186Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The effect of ester-based turbine oil on the performance characteristics of a tilting pad journal bearing was studied. Mineral oils with viscosity grade of 32 and 46 and synthetic oil with viscosity similar to that of the mineral oil VG32 were used. Both mineral and synthetic oils provided similar temperatures. Pad temperature was strongly affected by rotational speed. A slower increase in temperature at higher speeds was caused by the shift in the maximum temperature zone due to the pad thermal crowning. Synthetic oil ran slightly hotter than VG32 mineral oil at lower speeds. At higher speed these oils had almost the same temperatures. This is an abstract of a paper presented at the World Tribology Congress (Kyoto, Japan 9/6-11/2009).

  • 2. Glavatskih, Sergei
    et al.
    Norrby, Thomas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Torbacke, Marika
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Byheden, Åke
    Long term experience with environmentally adapted oils in hydrodynamic bearings of hydroelectric power plants2006Inngår i: 23rd IAHR Symposium on Hydraulic Machinery and Systems: Yokohama, Japan, October 17 - 21, 2006 ; [conference proceedings], 2006Konferansepaper (Fagfellevurdert)
  • 3.
    Kassfeldt, Elisabet
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Norrby, Thomas
    Rieglert, Jens
    SCA Packaging Munksund AB, Piteå.
    Wear and friction in boundary lubricated contacts2000Inngår i: The characteristics of interacting surfaces - a key factor in sustainable and economic products: 1st International Conference on Tribology in Environmental Design 2000 : held on the 4 - 6 September 2000, Bournemouth University, UK / [ed] M. Hadfield; C.. Ciantar, Bury St Edmunds: Professional Engineering Publishing Ltd , 2000, s. 195-204Konferansepaper (Fagfellevurdert)
  • 4.
    Larsson, Roland
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Kassfeldt, Elisabet
    Byheden, Åke
    Norrby, Thomas
    Base fluid parameters for EHL and friction calculations and their influence on lubrication capability2000Inngår i: Tribology 2000 - plus / [ed] W.J. Bartz, Techn. Akad. Esslingen , 2000, s. 1525-1536Konferansepaper (Fagfellevurdert)
  • 5.
    Larsson, Roland
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Kassfeldt, Elisabet
    Byheden, Åke
    Norrby, Thomas
    Base fluid parameters for elastohydrodynamic lubrication and friction calculations and their influence on lubrication capability2001Inngår i: Journal of Synthetic Lubrication, ISSN 0265-6582, Vol. 18, nr 3, s. 183-198Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, base fluid parameters for elastohydrodynamic lubrication (EHL) and friction analyses have been determined experimentally. The viscosity at atmospheric pressure, η0, the pressure-viscosity index, α and the EHL friction coefficient, γ, are important parameters in EHL theory and they are crucial in the selection of efficient lubricants for different applications. This investigation focuses on three important lubrication mechanisms: The capability of forming a separating lubricants film, the friction generated in a lubricated contact, and the height of pressure peaks, such as the outlet pressure spike and pressure ripple caused by surface roughness. The influence of different lubricant parameters on these three mechanism is discussed. The value of α is measured in a Couette high-pressure viscometer, and the value of γ is obtained from a jumping-ball device. Other parameters discussed are temperature-viscosity coefficient, β, bulk modulus, BO, thermal conductivity at atmospheric pressure, λO, and heat capacity unit volume, ρCpO. A comparison between traditional mineral base oils and environmentally adapted oil based on rapeseed oil and synthetic esters contributes to the further understanding of the performance of these new materials in lubrication applications. It is shown that rapeseed oil and synthetic esters have good lubricating properties and are, in most cases, better than mineral oils.

  • 6. 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).

  • 7. Norrby, Thomas
    Environmentally adapted lubricants: where are the opportunities?2003Inngår i: Industrial Lubrication and Tribology, ISSN 0036-8792, E-ISSN 1758-5775, Vol. 55, nr 6, s. 268-274Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Environmentally adapted lubricants (EALs) have been a slowly growing segment of the lubricants business since the early 1970s. The evolution of environmental thinking has led to the change of focus, from biodegradability to renewability. In the future, the focus will be more on fuel economy and lower emissions. Technical development drivers include the availability of suitable base fluids and additives for lubricants formulation and the adaptation of technical standards, OEM specifications and eco-labels. Important non-technical development drivers include environmental management tools and eco auditing. Environmental policy, and procurement guidelines for cities and government organizations, clearly has a large impact. EALs have been repeatedly heralded as one of the few future growth segments of the lubricants business, hence the relatively large increase in R&D activity over the last decade. In sales terms, growth has been slow, limited by high cost and several other factors. For a good future development, both technical and political hurdles must be overcome.

  • 8. Norrby, Thomas
    et al.
    Kopp, M.
    Environmentally adapted lubricants: vehicles for change in the transformation to sustainable industrial practices2002Inngår i: Proceedings of the 2002 environmental sustainability conference and exhibition, Society of Automotive Engineers, Incorporated , 2002, s. 411-416Konferansepaper (Fagfellevurdert)
  • 9. Norrby, Thomas
    et al.
    Kopp, M.
    Torbacke, M.
    Environmentally adapted lubricants in the Nordic marketplace: recent developments2002Inngår i: Industrial Lubrication and Tribology, ISSN 0036-8792, E-ISSN 1758-5775, Vol. 54, nr 3, s. 109-116Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Nordic marketplace, and in particular the Swedish market, is a sizeable part of the world market for environmentally adapted lubricants (EALs). The largest segment, by far, is EAL hydraulic fluids for mobile hydraulics, and chain saw oils for the environmentally adapted forestry operations (mainly) by the international Swedish and, until recently, Finnish forestry companies. In this paper, some of the important parameters influencing the size and development direction are analysed. These include market regulatory factors, eco-labels, OEM-issued standards/specifications, end-user demands and the market volume development for the period 1999-2001. The spread of EALs to other forestry markets, Norway and the Baltic States, is also covered.

  • 10. Norrby, Thomas
    et al.
    Kopp, Milan
    Environmentally adapted lubricants in Swedish forest industry: a critical review and case study2000Inngår i: Industrial Lubrication and Tribology, ISSN 0036-8792, E-ISSN 1758-5775, Vol. 52, nr 5, s. 116-125Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    During the last ten years, a gradual conversion from mineral oil based hydraulic fluids to environmentally adapted lubricants (EALs), has taken place in the forest industry in Sweden. The current market share of the EALs is ca. 80 percent of the mobile hydraulic fluids utilised. The original driving force of this change can be traced to end-user demands, especially paper and pulp consumers in Germany. The Swedish standard SS 15 54 34 was in 1997 supplemented with environmental criteria derived from the "Ren Smörja" ("Clean Lubrication") environmental project in the city of Göteborg. The reliable third-party validation offered by SP (Swedish National Testing and Research Institute), the present stewards of the "Clean Lubrication" list, has proven to be another important factor. By comparison to the German Blue Angel Eco-labelling scheme, the Swedish SP-list approval is somewhat easier to attain, and has provided a flexible base for the development of new products.

  • 11. Norrby, Thomas
    et al.
    Kopp, Milan
    Miljöanpassade smörjmedel i den svenska skogen: en historik2000Inngår i: Fluid Scandinavia, ISSN 1402-103X, nr 2, s. 35-47Artikkel i tidsskrift (Annet vitenskapelig)
  • 12. Norrby, Thomas
    et al.
    Torbacke, Marika
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Byheden, Åke
    Svenska Statoil AB, Lubricants R and D.
    Glavatskih, Sergei
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    EALs for hydropower applications, Part 2: turbine oil development and field testing2006Inngår i: Automotive and industrial lubrication: 15th International Colloquium Tribology, January 17 - 19, 2006 ; [book of synopses 2006] / [ed] Wilfried J. Bartz, Ostflindern: Techn. Akad. Esslingen , 2006, s. 144-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Research regarding environmentally adapted lubricants results of the research performed at Luleå University of Technology were positive. Thus, the formulation work of an environmentally adapted lubricant for hydropower applications started. A change to a synthetic ester based lubricant would give technical advantages as well as environmental benefits. The initial tests were conducted on the base fluid. Two turbine oils were developed, Turb Way SE and TurbWay SE LV, for hydropower applications. Oxidation tests were performed in both the RPVOT (ASTM D 2272) and in TOST (ASTM D 943). The stability of the turbine oil was > 20 times better than tested environmentally adapted hydraulic fluids. Field tests were conducted in a full scale turbine at Porjus hydropower plant to confirm the promising results obtained from the research in the tilting thrust bearing rig. This is an abstract of a paper presented at the 15th International Colloquium Tribology - Automotive and Industrial Lubrication (Ostfildern, Germany 1/17-19/2006).

  • 13.
    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).

  • 14. Pettersson, Anders
    et al.
    Larsson, Roland
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Norrby, Thomas
    Andersson, O.
    Properties of base fluids for environmentally adapted lubricants2001Inngår i: Tribology 2001 : scientific achievements, industrial applications, future challenges: plenary and session key papers from the 2nd World Tribology Congress, Vienna, Austria, 3 - 7 September / [ed] Friedrich Franek, Wien: ÖTG , 2001Konferansepaper (Fagfellevurdert)
  • 15. Pettersson, Anders
    et al.
    Larsson, Roland
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Norrby, Thomas
    Andersson, Ove
    Umeå university.
    Properties of base fluids for environmentally adapted lubricants2002Inngår i: Handbook of Tribology and Lubrication, Renningen: Expert Verlag , 2002, s. 52-55Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 16. Våg, C.
    et al.
    Marby, A.
    Kopp, Milan
    Furberg, L.
    Norrby, Thomas
    A comparative life cycle assessment of the manufacture of base fluids for lubricants2002Inngår i: Journal of Synthetic Lubrication, ISSN 0265-6582, Vol. 19, nr 1, s. 39-57Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A comparative life cycle assessment (LCA) study of three types of base oils used in the manufacture of hydraulic fluids has been carried out, and is reported here. The fluid types investigated are a mineral oil, a synthetic ester, and a rape seed triglyceride oil. The applications chosen for the finished lubricants are in mobile hydraulic systems in forestry operations, some of which are almost 100% total loss applications. The scope and limitations of the LCA model are discussed, and conclusions drawn concerning the application of LCA models as evaluation tools for the development of environmentally adapted lubricants. The methodology used is compatible with the ISO 14000-type industrial standard.

  • 17. Waara, Patric
    et al.
    Hannu, J.
    Norrby, Thomas
    Byheden, Åke
    Additive influence on wear and friction performance of environmentally adapted lubricants2002Inngår i: Lubricants, materials and lubrication engineering: January 15 - 17, 2002 / 13th International Colloquium Tribology. Technische Akademie Esslingen / [ed] Wilfried J. Bartz, Ostfildern: Techn. Akad. Esslingen , 2002, s. 549-558Konferansepaper (Fagfellevurdert)
  • 18. Waara, Patric
    et al.
    Hannu, Jesper
    Luleå tekniska universitet.
    Norrby, Thomas
    Byheden, Åke
    Additive influence on wear and friction performance of environmentally adapted lubricants2001Inngår i: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 34, nr 8, s. 547-556Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, the influence of concentration level and chemical composition of three different additive types on friction and wear coefficient are presented for a synthetic ester base fluid and a mineral base oil. One extreme-pressure (EP), two antiwear (AW) and two yellow metal passivator (Cu-passivators) additives were used. Factorial experimental design was used as the basis for a systematic evaluation of wear rates under mixed and boundary lubrication conditions. A total of 33 different lubricant blends were tested in a Plint and Partner High Frequency Friction Machine. For the synthetic ester, the extreme-pressure (EP) additive, containing phosphorus and nitrogen, was found to be much more effective in reducing wear than either of the two antiwear (AW) additives tested. In fact, the AW and Cu-passivator additives made little or no contribution to the wear protection in most of the cases studied. A synergy effect between the three additive combinations was observed only for the reference mineral oil blend. A significant difference between the antiwear performance of the test lubricants was found. This study suggests that the traditional "AW" and "EP" labels associated with commonly used additives are poor aids when designing of ester based lubricants.

  • 19. Waara, Patric
    et al.
    Norrby, Thomas
    Prakash, Braham
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    Tribochemical wear of rail steels lubricated with synthetic ester-based model lubricants2004Inngår i: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 17, nr 3, s. 561-568Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Headchecks are a common type of damage in heavily loaded curved freight tracks. This paper deals with synthetic ester formulations' ability to prevent damage caused by headchecks through mild tribochemical wear. An experimental study pertaining to wear and friction of two rail steels lubricated by two synthetic ester base fluids, TMP-oleate and TMP-C8-C10, has been carried out. Six different free fatty acids were used in this study to act as performance additives. Three of the fatty acids were mono-acids with different, straight, carbon chain lengths (stearic acid C18, decanoic acid C10 and octanoic acid C8), one was a mono-unsaturated straight-chain fatty acid (oleic acid C18:1) while two were dibasic acids with intermediate carbon chain length (C9 and C10). Each fatty acid was blended with either ester, one at a time. The tests were carried out by using a high frequency reciprocating friction and wear test machine. In these tests, the gage face/wheel flange contact was simulated, and all tests were conducted in the boundary lubrication regime. An initial contact pressure of 316 MPa and a maximum sliding speed of 0.11 m/s were employed during the tests. The tests showed a wide range of wear rates, as well as different surface features depending on the interactions between synthetic esters, fatty acids and steel. The use of stearic and azaleic acid in lubricating rail steels results in very smooth surfaces with significant differences in their wear rates.

  • 20. Åhrström, Bert-Olof
    et al.
    Penchinat, C.
    Option Matériaux, Ecole Centrale de Nantes.
    Norrby, Thomas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Maskinelement.
    An experimental study of the influence of heat storage and transportability of different lubricants on friction under transient elastohydrodynamic conditions2003Inngår i: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 217, nr 1, s. 27-37Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lubricated transient elastohydrodynamic (EHD) conjunctions are extremely difficult to simulate numerically since lubricant properties such as temperature and viscosity vary significantly during the loading-unloading event. Nevertheless, industry has invested considerable time and effort in trying to create such models in order to improve performance and to reduce emissions and friction. One of the essential requirements for a successful model is accuracy in the implementation of frictional properties. The experimental method presented in this paper used an impact on the end surface of a beam to generate propagating waves that were subjected to fast Fourier transform analysis. The method yielded detailed information about the build-up and decay of normal and frictional forces as a function of time for various lubricants at three different initial temperatures (20, 40 and 80 °C) and at relevant EHD pressures. A variety of lubricants were studied to a peak Hertzian pressure of 2.5 GPa for loading-unloading times of 200-400 µs (typical for elastohydrodynamically lubricated conjunctions in ball bearings and gears). A qualitative study of the thermal properties of the lubricants and their influence on viscosity and friction coefficient was also undertaken and, finally, a plausible explanation of the observed behaviour is presented and parallels to dynamic simulations of polyatomic gases are drawn.

1 - 20 of 20
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