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  • 1. Baart, Pieter
    et al.
    Green, Torbjörn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Li, Jinxia
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lundström, T. Staffan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Westerberg, Lars-Göran
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lugt, Piet
    SKF Engineering & Research Center, Nieuwegein.
    Contaminant particle migration in a double restriction seal2013In: Proceedings of the STLE Annual Meeting and Exhibition 2013, Detroit MI, USA., STLE , 2013, p. 125-Conference paper (Refereed)
    Abstract [en]

    Microparticle image velocimetry (μPIV) is used to measure the grease velocity profile in small seal-like geometries and the radial migration of contaminant particles is predicted. In the first part, the influence of shaft speed, grease type, and temperatures on the flow of lubricating greases in a narrow double restriction sealing pocket is evaluated. Such geometries can be found in, for example, labyrinth-type seals. In a wide pocket the velocity profile is one-dimensional and the Herschel-Bulkley model is used. In a narrow pocket, it is shown by the experimental results that the side walls have a significant influence on the grease flow, implying that the grease velocity profile is two-dimensional. In this area, a single empirical grease parameter for the rheology is sufficient to describe the velocity profile.In the second part, the radial migration of contaminant particles through the grease is evaluated. Centrifugal forces acting on a solid spherical particle are calculated from the grease velocity profile. Consequently, particles migrate to a larger radius and finally settle when the grease viscosity becomes large due to the low shear rate. This behavior is important for the sealing function of the grease in the pocket and relubrication

  • 2. Baart, Pieter
    et al.
    Green, Torbjörn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Li, Jinxia
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lundström, T. Staffan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Westerberg, Lars-Göran
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lugt, Piet
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    The influence of speed, grease type, and temperature on radial contaminant particle migration in a double restriction seal2011In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 54, no 6, p. 867-877Article in journal (Refereed)
    Abstract [en]

    Microparticle image velocimetry (μPIV) is used to measure the grease velocity profile in small seal-like geometries and the radial migration of contaminant particles is predicted. In the first part, the influence of shaft speed, grease type, and temperatures on the flow of lubricating greases in a narrow double restriction sealing pocket is evaluated. Such geometries can be found in, for example, labyrinth-type seals. In a wide pocket the velocity profile is one-dimensional and the Herschel-Bulkley model is used. In a narrow pocket, it is shown by the experimental results that the side walls have a significant influence on the grease flow, implying that the grease velocity profile is two-dimensional. In this area, a single empirical grease parameter for the rheology is sufficient to describe the velocity profile. In the second part, the radial migration of contaminant particles through the grease is evaluated. Centrifugal forces acting on a solid spherical particle are calculated from the grease velocity profile. Consequently, particles migrate to a larger radius and finally settle when the grease viscosity becomes large due to the low shear rate. This behavior is important for the sealing function of the grease in the pocket and relubrication.

  • 3.
    Baart, Pieter
    et al.
    SKF Engineering & Research Center, Nieuwegein.
    Lugt, Piet
    SKF Engineering & Research Center, Nieuwegein.
    Westerberg, Lars-Göran
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Green, Torbjörn
    Li, Jinxia
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lundström, T. Staffan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Sealing improvements by grease selection in double lip seals and labyrinth seals2012In: 17th ISC: International Sealing Conference ; Stuttgart, Germany, Sept. 13 - 14, 2012, Frankfurt am Main: Fachverband Fluidtechnik im VDMA e.V , 2012Conference paper (Refereed)
  • 4.
    Biledt, Egil
    et al.
    Luleå tekniska universitet.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Rasborraggregatens hydrauloljeförbrukning vid LKAB i Kiruna1994Report (Other academic)
  • 5.
    Biledt, Egil
    et al.
    Luleå tekniska universitet.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Studie av hydraulcylindrar till TORO lastmaskiner vid LKAB i Kiruna1993Report (Other academic)
  • 6.
    Biledt, Egil
    et al.
    Luleå tekniska universitet.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Temperaturens inverkan på O-ringar till gruvlastare1992Report (Other academic)
  • 7.
    Biledt, Egil
    et al.
    Luleå tekniska universitet.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Tillståndskontroll av hydraulsystem på gruvlastare före och efter ombyggnad av returfilter1992Report (Other academic)
  • 8.
    Biledt, Egil
    et al.
    Luleå tekniska universitet.
    Tiberg, Sven-Erik
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Analys av driftsförhållanden i hydraulsystem till gruvlastare, typ Bison1990Report (Other academic)
  • 9.
    Duenas Dobrowolski, Jan
    et al.
    Department of Design Fundamentals and Fluid-Flow Machinery, Wrocaw University of Technology, Wrocaw, Poland.
    Gawlinski, Marek
    Department of Design Fundamentals and Fluid-Flow Machinery, Wrocaw University of Technology, Wrocaw, Poland.
    Paszkowski, Maciej
    Department of Fundamentals of Machine Design and Tribology, Wrocaw University of Technology, Wrocaw, Poland.
    Westerberg, Lars-Göran
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Experimental Study of Lubricating Grease Flow inside the Gap of a Labyrinth Seal Using Microparticle Image Velocimetry2018In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 61, no 1, p. 31-40Article in journal (Refereed)
    Abstract [en]

    In this study, the flow of lubricating greases in a labyrinth seal geometry is studied using microparticle image velocimetry (µPIV). The aim is to evaluate the grease velocity distribution inside the gap of a labyrinth seal and to find a relationship between the grease consistency and the transferred speed from the rotating ring in order to choose the correct grease as a sealing medium. In addition, the grease flow characteristics are important for the understanding of fracture due to grease layer displacement. For these purposes, four greases with different rheological properties were used in µPIV experiments. It was found that the grease consistency plays a crucial role in speed development as well as the grease composition and presence of a slip effect at the grease–rotating wall interface.

  • 10.
    Emami, Nazanin
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Larsson, Roland
    Höglund, Erik
    Biotribology: surface chemistry characterization of metal-on-metal implants in rich environment2008In: 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, 2008Conference paper (Refereed)
    Abstract [en]

    Introduction: Osteolysis induced by wear particles in metal-on-polyethylene hip implants has been the key motivation to look for alternative bearings and in fact emergence and development of new metal-on-metal (MOM) implant materials for joint replacement. However, while the volume of wear particles produced in metal-on-metal articulations is lower the number of particles produced is higher per volume of wear, due to the reduced size of wear particles. Although various surface and interface characterization methods have been applied to study the physical wear, corrosion and implant surface interactions with biological environments, presently the local and systematic effects of metal debris are poorly understood. Materials and Methods: Cobalt-chromium-molybdenium (CoCr) alloys have been used in MOM implants extensively. Metallic samples were cut and mirror polished. In the present study The samples were immersed in four different biological lubricants (Human serum, synovial fluid, MEM and Milli-Q water) for 10 min, 1 hr, and 5 days of immersion and then studied by X-ray Photoelectron Spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (ToF-SIMS). XPS determined the chemistry of elements located whitin the top few nanometers of materials. Significant differences in the absorbed layers and differences in the corrosive nature of Ti and CoCr implant substrates and wear particles were found. Results and discussion: Spectra from P 2p3/2, O1s, Ca2p3/2, C1s and N1s were collected. Metallic substrates behaved differently when immersed in the same lubricant. The four lubricants reacted different with metallic surfaces. Larger calcium deposits occurred in supersaturated physiological solutions. Deposition of calcium phosphate was different on CoCr alloys depending on the lubricant and the immersion period. Specimens immersed into synovial fluid gave thinner oxide layers and lower calcium phosphate deposits. For all specimens, water immersion resulted in thicker oxide layer. For many reactive metals, dissolution of ions from the metal surface takes place along with thickening of the metal oxide during passivation, or surface corrosion.Conclusion: Glycoaminoglycans (GAG) and related proteins may hinder calcium phosphate deposition on samples immersed in synovial fluid. ToF-SIMS measurements showed that the resulting corrosion products depend upon the nature of the environment. The thickness of the calcium phosphate deposits was different for different metal substrate.

  • 11. Glavatskih, Sergei
    et al.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Tribotronics, towards active tribology2006In: Nordtrib 2006, 12th Nordic Tribology Symposium, Denmark: [LO-skolen, Helsingør, Denmark, June 7 - 9 2006], Kongens Lyngby: Technical University of Denmark , 2006Conference paper (Refereed)
  • 12. Glavatskih, Sergei
    et al.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Tribotronics: towards active tribology2008In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 41, no 9-10, p. 934-939Article in journal (Refereed)
    Abstract [en]

    A constant trend towards more compact mechanical systems with higher power densities and increased thermo-mechanical loads emphasises the importance of the development of new design approaches and novel tribological systems. Ignoring this may cause a significant slow down in technological and industrial development. Tribotronics or active tribology based on adaptive performance is thought of as being critical in the implementation of smart machine concepts. Recognition of the importance of tribotronics, or active control of system loss outputs, such as those through friction and wear will have significant beneficial economic consequences as a result of the associated accelerated rate of technological progress. These smart tribotronic systems can be embedded in a great variety of machines and mechanisms. If this integration is made at the design stage, products that are more flexible, efficient and reliable can be produced. The concept of tribotronics is presented and discussed in this paper. Some illustrative examples that show the feasibility of an “active” approach are given. In addition, various possibilities already reported in literature are discussed.

  • 13. Glavatskih, Sergei
    et al.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Larsson, Roland
    Hydrodynamic thrust bearing experimental apparatus for testing environmentally adapted oils1998In: Tribologia : Finnish Journal of Tribology, ISSN 0780-2285, Vol. 17, no 2, p. 27-30Article in journal (Refereed)
    Abstract [en]

    There are indications that some environmentally friendly oils provide performance advantages in hydrodynamic bearings compared to mineral oils. To verify and to quantify the advantages of the synthetic oils in hydrodynamic lubrication in terms of operating film thickness, bearing power loss and operating temperature, a test rig for laboratory experiments has been designed and manufactured. At the first stage of the project temperature and pressure distributions, power loss and oil film thickness for ISO VG46 and VG68 mineral and synthetic oils will be measured at different loads and rotational speeds. At the next stage several other lubricants will be tested. Among them rape seed oil and pine tree oil can be mentioned.

  • 14. Glavatskih, Sergei
    et al.
    Höglund, Erik
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Hydrodynamic thrust bearing experimental apparatus for testing environmentally adapted oils1998In: COST 516 Tribology Symposium, Espoo, Finland, 14 - 15 May 1998: Organised by Technical Research Centre of Finland, Manufacturing Technology / [ed] Helena Ronkainen, Espoo: Technical Research Centre of Finland (VTT) , 1998Conference paper (Refereed)
  • 15.
    Glavatskih, Sergei
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Höglund, Erik
    Larsson, Roland
    Influence of oil type on hydrodynamic thrust bearings performance2000In: Tribology at work, Elsevier, 2000Conference paper (Refereed)
  • 16. Glavatskih, Sergei
    et al.
    Höglund, Erik
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    On power measurement in hydrodynamic thrust bearings1999In: COST 516 Tribology Symposium: Antwerpen, Belgium, 20 - 21 May 1999 / [ed] Karen Vercammen; Jan Meneve, Mol: Flemish Institute for Technological Research , 1999Conference paper (Refereed)
  • 17.
    Glavatskih, Sergei
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Höglund, Erik
    Larsson, Roland
    Testing environmentally adapted oils for hydrodynamic lubrication2000In: Proceedings of the 3rd COST 516 Tribology symposium: Eibar, Spain, 18 and 19 May 2000 / [ed] Amaya Igartua; Alberto Alberdi, Elbar: Tekniker , 2000Conference paper (Refereed)
  • 18.
    Green, Torbjörn
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Baart, Pieter
    Westerberg, Lars-Göran
    Lundström, Staffan
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lugt, Piet
    Li, Jinxia
    A new method to visualize grease flow in a double restriction seal using microparticle image velocimetry2011In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 54, p. 784-792Article in journal (Refereed)
    Abstract [en]

    A new method to visualize and quantify grease flow in between two sealing lips or, in general, a double restriction seal is presented. Two setups were designed to mimic different types of seals; that is, a radial and an axial shaft seal. The flow of the grease inside and in between the sealing restrictions was measured using microparticle image velocimetry. The results show that grease flow due to a pressure difference mainly takes place close to the rotating shaft surface with an exponentially decaying velocity profile in the radial direction. Consequently, contaminants may be captured in the stationary grease at the outer radius, which explains the sealing function of the grease.

  • 19.
    Green, Torbjörn
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Baart, Pieter
    Westerberg, Lars-Göran
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Lundström, T. Staffan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lugt, Piet
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Li, Jinxia
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Visualisering och kvantifiering av fettströmning i lagertätningar med µPIV2011Conference paper (Other academic)
  • 20.
    Gustafsson, Lennart
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Marklund, Olov
    Measuring lubricant film thickness with image analysis1993Report (Other academic)
  • 21.
    Gustafsson, Lennart
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Embedded Internet Systems Lab.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Marklund, Olov
    Measuring lubricant film thickness with image analysis1994In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 208, p. 199-205Article in journal (Refereed)
  • 22.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Bestämning av skjuvhållfasthetens tryckberoende hos växellådsoljor1991Report (Other academic)
  • 23.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Determining EHD film thickness using image processing1996In: Tribology - solving friction and wear problems: 10th international colloquium, 09 - 11 January 1996 ; Plenarvorträge / [ed] Wilfried J. Bartz, Ostfildern: Techn. Akad. Esslingen , 1996Conference paper (Refereed)
  • 24.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    EHL and the use of image analysis1994In: Nordtrib '94: proceedings of the 6th Nordic Symposium on Tribulogy ; 12 - 15 June 1994, Uppsala, Sweden / [ed] P. Hedenqvist, Uppsala, 1994Conference paper (Refereed)
  • 25.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    EHL and the use of image analysis1994In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 179, no 1-2, p. 49-56Article in journal (Refereed)
    Abstract [en]

    This paper describes three cases where image analysis has been used to evaluate transient phenomena in elastohydrodynamic lubrication (EHL). In the first case, a CCD camera and image analysis are used to evaluate the ball trajectory after impact in the "jumping ball apparatus" for subsequent calculation of the limiting shear stress-pressure coefficient. The error of the method is < 1%. In the second case, the motion of the rollers in a roller bearing is traced with a video camera and image analysis. The rolling and sliding motion in the loaded and unloaded parts of the bearing was clearly visible. Although the shaft speed was only 23.6 rpm, the method can easily be used up to 1500 rpm using a conventional high speed video and up to 27 000 rpm with a 6000 pictures per second video camera. In the third case, the method was applied to interferograms of an EHL point contact to investigate lubricant film thickness. The method uses hue, saturation and intensity values from digitized colour interferometric images together with calibration vales. It can be used to evaluate transient as well as quasistatic phenomena in the contact. The method makes it possible to determine absolute values of film thickness without prior knowledge about the fringe order in the interferogram. The method has been shown to work well in the range 140-700 nm with white light but preliminary tests for considerably thicker films are very promising

  • 26.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Elastohydrodynamic lubrication: interferometric measurements, lubricant rheology and subsurface stresses1984Doctoral thesis, comprehensive summary (Other academic)
  • 27.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Elastohydrodynamic lubrication, lubricant rheology and subsurface stresses1985In: Vol. 4, no 1Article in journal (Refereed)
  • 28.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Forskning för kalla fakta1990In: Teknik och vetenskap, ISSN 0282-9274, no 5Article in journal (Other (popular science, discussion, etc.))
  • 29.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Influence of lubricant properties on elastohydrodynamic lubrication1998In: Proceedings of the 8th International Conference on Tribology: Hotel Ebeltoft Strand, Ebeltoft, Denmark, June 7 - 10, 1998 / [ed] Svens D. Eskildsen, Aarhus: DTI Tribology Centre , 1998Conference paper (Refereed)
  • 30.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Influence of lubricant properties on elastohydrodynamic lubrication1999In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 232, no 2, p. 176-184Article in journal (Refereed)
    Abstract [en]

    In hard EHL, encountered in, e.g., gears, rolling element bearings etc. the properties of the lubricant play a significant role in the forming of a lubricating film and reducing friction between the contacting surfaces. The influence of pressure and temperature on viscosity, limiting shear stress and density, has to be taken into account when creating lubricant models to be used in numerical calculations of film thickness and friction. This paper describes some experimental methods to determine these properties of a number of different lubricating oils, both from mineral, vegetable and synthetic origin. The results show that, apart from 5P4E, naphthenic mineral oil has the highest values of pressure-viscosity as well as limiting shear stress-pressure coefficients. It also exhibits the highest density increase with pressure. Rapeseed oil has a rather high pressure-viscosity coefficient but a low limiting shear stress-pressure coefficient as well as a low density increase with pressure. Thus, rapeseed oil is a strong alternative to naphthenic (and also paraffinic) oil since it has the ability to form a relatively thick oil film and at the same time give a low coefficient of friction. Ester, polyglycol and polyalphaolefin oils also exhibit low values of friction but are not equally good as rapeseed oil to form a lubricant film as a result of their lower pressure-viscosity coefficients

  • 31.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Influence of polyalkylmethacrylate and sulphurized ester on oil film thickness in an elastohydrodynamic point contact1987In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 115, no 1-2, p. 223-234Article in journal (Refereed)
    Abstract [en]

    The aim of this investigation is to determine how additives in a base oil affect the central oil film thickness in an elastohydrodynamic rolling point contact. The experiments have been carried out using a sapphire disc and a steel ball and the film thickness has been measured by means of optical interferometry. A detailed description of the apparatus is given.Two different additives have been used, polyalkylmethacrylate (PMA) and sulphurized ester (SE). Each of them have been mixed in a superrefined naphthenic base oil at five different concentrations.The results show that the central oil film thickness increases with increasing concentration of additive. This is because the additives increase the oil viscosity. If this effect is compensated for, 0.1 wt.% PMA or 0.63-2.5 wt.% SE give the best relative oil film build-up. There is consequently no reason to use more additive in the base oil unless one wants to have a thicker oil film because of the viscosity-increasing effect

  • 32.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Inverkan av polymetakrylat och sulfuriserad linjär ester på oljefilmstjockleken i en elastohydrodynamiskt smord punktkontakt1984Report (Other academic)
  • 33.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Measurement of the influence of additives on oil film thickness in an elastohydrodynamic point contact1982In: Proceedings of the Eighth Symposium on Thermophysical Properties: presented at National Bureau of Standards, Gaithersburg, Maryland, June 15 - 18, 1981 / sponsored by National Bureau of Standards ... / [ed] Jan V. Sengars, New York: American Society of Mechanical Engineers , 1982Conference paper (Refereed)
  • 34.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Mätning av friktion i en fettsmord kontakt1991Report (Other academic)
  • 35.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Provning av egenskaper hos smörjmedel1984In: Utrustning och metoder för friktions- och nötningsprovning: sammanfattningar från temadag i Uppsala 22 maj 1984, Uppsala, 1984Conference paper (Refereed)
  • 36.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Reduced limiting shear stress: a way to increase efficiency and life of machines1990In: Proceedings of the Japan International Tribology Conference Nagoya, 1990 : oct. 29 - nov. 1, 1990, Tokyo: Japan Society of Tribologists , 1990Conference paper (Refereed)
  • 37.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Relationship between lubricant shear strength and chemical composition of the base oil1989In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 130, no 1, p. 213-224Article in journal (Refereed)
    Abstract [en]

    A new method for the experimental evaluation of the shear strength of lubricants at high pressures and temperatures is presented. The main parts of the experimental apparatus are a lubricated sintered-carbide surface and an impacting steel ball. A picture-processing system is used to examine the ball trajectory after impact and to calculate the limiting shear strengthpressure coefficient of the lubricant. Using this apparatus the influence of the chemical composition of the base oil on the limiting shear strengthpressure coefficient has been investigated. It was found that the chemical structure of the oil is of major importance in determining the shear strength. Additives have no significant effect on the shear strength.

  • 38.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Slitage av labyrinttätningar1988Report (Other academic)
  • 39.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Slitage av lagerfoder vid baxning av axlar1987Report (Other academic)
  • 40.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Some basic properties of environmentally adapted oils1998In: COST 516 Tribology Symposium, Espoo, Finland, 14 - 15 May 1998 / [ed] Helena Ronkainen, Espoo: Technical Research Centre of Finland (VTT) , 1998Conference paper (Refereed)
  • 41.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Subsurface stresses in a lubricated rolling/sliding elastohydrodynamic line contact considering limited shear strength of the lubricant1986In: Mechanisms and surface distress: global studies of mechanisms and local analyses of surface distress phenomena : proceedings of the 12th Leeds-Lyon Symposium on Tribology ... 1985 / [ed] Duncan Dowson, London: LexisNexis Butterworths, 1986Conference paper (Refereed)
  • 42.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Tribology: perspectives for the 21st century1990In: 3rd International tribology conference: Selected papers, Tokyo: Japan Society of Tribologists , 1990Conference paper (Refereed)
  • 43.
    Höglund, Erik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Tribology research at Luleå University of Technology1991In: Tezisy dokladov / Meždunarodnyj Sovetsko-Skandinavskij Seminar Mašiny, Materialy i Konstrukcii v Arktičeskich Uslovijach = Abstracts / International Soviet-Scandinavian Seminar Machines, Materials and Structures in Arctic Conditions, 1991Conference paper (Refereed)
  • 44.
    Höglund, Erik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Jacobson, Bo
    Luleå tekniska universitet.
    Closure to "Discussion of `Experimental Investigation of the Shear Strength of Lubricants Subjected to High Pressure and Temperature'1986In: Journal of tribology, ISSN 0742-4787, E-ISSN 1528-8897, Vol. 108, no 4, p. 578-Article in journal (Other academic)
  • 45.
    Höglund, Erik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Jacobson, Bo
    Luleå tekniska universitet.
    Experimental investigation of the shear strength of lubricants subjected to high pressure and temperature1986In: Journal of tribology, ISSN 0742-4787, E-ISSN 1528-8897, Vol. 108, no 4, p. 571-577Article in journal (Refereed)
    Abstract [en]

    In order to evaluate the relationship between limiting shear strength and pressure for a lubricant an experimental apparatus has been built. Pressures up to 2. 2 GPa and temperatures up to 200 degree C are attainable simultaneously. Thus the limiting shear strength-pressure relationship has been surveyed in a wide range. Several types of natural and synthetic lubricants have been tested. The results show that all the mineral oils tested behave in quite a similar way. Synthetic lubricants do not show this behavior, but the relationship between limiting shear strength and pressure depends strongly upon the chemical base of the synthetic lubricants. The behavior of grease does not differ from that of liquid lubricants. The pressures at which the lubricants change from a liquid to a solid behavior have also been measured.

  • 46.
    Höglund, Erik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Jonsson, Ulf
    Luleå tekniska universitet.
    Uusitalo, Östen
    Luleå tekniska universitet.
    Effect of pressurised gases on the viscosity of polyalkylene glycols1997In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 207, no 1-2, p. 24-28Article in journal (Refereed)
    Abstract [en]

    Experiments have been conducted into the effect of pressurised hydrocarbons on the viscosity of a polyalkylene glycol. This lubricant is intended to be used in a sub-sea compressor/pump unit and the risk of diluting the lubricant by the surrounding natural gas, thus reducing the lubricant's viscosity, was to be investigated. Dilution can cause insufficient lubrication of the compressor's moving parts. A pressurised Höppler type viscometer was used for the tests which were conducted at 50 °C with a methane based hydrocarbon mixture and with pure nitrogen. The viscosity of the lubricant was reduced to 24% after 24 h exposure at 100 bar with the hydrocarbon mixture. A gas analysis was performed which indicates that the heavier hydrocarbons used are relatively soluble in the lubricant even at relatively low pressures. Nitrogen was found to have a very limited effect on the viscosity even if some was dissolved in the oil. A long duration test of 11 days was also made with nitrogen. This test did not show any significant reduction of the viscosity.

  • 47.
    Höglund, Erik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Jonsson, Ulf
    Uusitalo, Östen
    The effect of pressurised gasses on the viscosity of polyalkylene glycol1994Report (Other academic)
  • 48. Höglund, Erik
    et al.
    Larsson, Roland
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Modelling non-steady EHL with focus on lubricant density1997In: Elastohydrodynamics -'96: fundamentals and applications in lubrication and traction : proceedings / [ed] D. Dowson, Amsterdam: Elsevier, 1997, p. 511-521Conference paper (Refereed)
  • 49.
    Höglund, Erik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Lundberg, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Influence of limiting shear stress of oils on failure of a lubricating oil film1992In: Vol. 11, no 2-4Article in journal (Refereed)
  • 50.
    Höglund, Erik
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Machine Elements.
    Uusitalo, Östen
    Luleå tekniska universitet.
    Labyrinttätningens slitstyrka1993Report (Other academic)
123 1 - 50 of 123
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