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Johansson, Jens
Publications (10 of 11) Show all publications
Johansson, J., Devlin, M. T., Guevremont, J. M. & Prakash, B. (2019). Improving Hypoid Gear Oil Pitting Performance through Friction Reduction. Tribology Transactions
Open this publication in new window or tab >>Improving Hypoid Gear Oil Pitting Performance through Friction Reduction
2019 (English)In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397XArticle in journal (Refereed) Epub ahead of print
Abstract [en]

Earlier studies have shown that the load-dependent friction behavior of various gear oils can affect their pitting performance; that is, low friction resulted in a long pitting life. These studies were limited, however, to test methods and running conditions quite different from those occurring in actual gear transmissions. In the present study, a more gear-like twin-disc machine with test specimens and running conditions relevant for gear contacts was used to investigate whether the same trends could be found. To analyze this possible correlation, the first step was to prepare a set of hypoid gear oils and to test their friction performance to compare various ways of improving friction behavior but also to form an understanding of why their friction performance varied. The second step was to test the pitting performance of the oils. The pitting results could then be compared to the friction properties of the oils to analyze the correlation. Other possible mechanisms behind the formation of pits are also discussed. The results show that for the oils included, the antiwear and extreme-pressure additive package and the base oil type affect friction. The results further show that additive combinations and/or base oils that result in low friction lead to enhanced pitting performance.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
Gear lubricants, rolling contact fatigue, EHL friction, antifatigue additives
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-76575 (URN)10.1080/10402004.2019.1686194 (DOI)000497233100001 ()2-s2.0-85075217917 (Scopus ID)
Available from: 2019-10-30 Created: 2019-10-30 Last updated: 2019-12-10
Burkhart, C., Johansson, J., Uukonsari, J. & Prakash, B. (2018). Performance of lubricating oils for wind turbine gear boxes and bearings. Paper presented at 17th Nordic Symposium on Tribology - NORDTRIB 2016, Hämeenlinna, Finland, 14th - 17th June 2016. Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, 232(1), 62-72
Open this publication in new window or tab >>Performance of lubricating oils for wind turbine gear boxes and bearings
2018 (English)In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 232, no 1, p. 62-72Article in journal (Refereed) Published
Abstract [en]

In this study, the friction and wear properties of six different new and used wind turbine gear oils (ISO VG 320), with different base oil formulations and additives packages, were investigated. For that purpose, a four-ball tribometer and an Optimol SRV were used. Moreover, the lubricants extreme pressure properties were also evaluated, using the same four-ball tribometer. The study also includes a characterization of the lubricants. The main objective was to compare the new and used gear oils in order to identify performance differences and predict oil change intervals. The results indicate that a use of 3 to 4 years is within the lifetime of the lubricant.

Place, publisher, year, edition, pages
Sage Publications, 2018
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-66356 (URN)10.1177/1350650117739764 (DOI)000419852700007 ()2-s2.0-85040449368 (Scopus ID)
Conference
17th Nordic Symposium on Tribology - NORDTRIB 2016, Hämeenlinna, Finland, 14th - 17th June 2016
Note

Konferensartikel i tidskrift

Available from: 2017-11-02 Created: 2017-11-02 Last updated: 2018-01-25Bibliographically approved
Sharma, V., Johansson, J., Timmons, R. B., Prakash, B. & Aswath, P. B. (2018). Tribological Interaction of Plasma-Functionalized Polytetrafluoroethylene Nanoparticles with ZDDP and Ionic Liquids. Tribology letters, 66(3), Article ID 107.
Open this publication in new window or tab >>Tribological Interaction of Plasma-Functionalized Polytetrafluoroethylene Nanoparticles with ZDDP and Ionic Liquids
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2018 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 66, no 3, article id 107Article in journal (Refereed) Published
Abstract [en]

Polytetrafluoroethylene (PTFE) nanoparticles were coated with consecutive plasma deposited siliceous and methacrylate coatings. Secondary zinc dialkyldithiophosphate (ZDDP), phosphonium cation and phosphate anion ionic liquid (IL), and IL with phosphonium cation and dithiophosphate anion were mixed with the functionalized nanoparticles. Tribological studies were carried out for seven separate formulations including base oil, oils with only additives, and oils with additives and functionalized PTFE particles. Results indicate strong synergistic interactions of ZDDP and ILs with functionalized nanoparticles providing enhanced friction and wear performance. Chemical analysis of the tribofilms using X-ray photoelectron spectroscopy and X-ray absorption near edge structure spectroscopy indicates functionalized PTFE nanoparticles interact synergistically with ZDDP and ILs to form silicon- and fluorine-doped tribofilms resulting in superior tribological performance.

Place, publisher, year, edition, pages
Springer, 2018
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-70290 (URN)10.1007/s11249-018-1060-8 (DOI)000440114500001 ()2-s2.0-85051101013 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-08-09 (andbra)

Available from: 2018-08-09 Created: 2018-08-09 Last updated: 2018-08-16Bibliographically approved
Tormos, B., Ramíreza, L., Johansson, J. & Larsson, R. (2017). Fuel Consumption and Friction Benefits of Low Viscosity Engine Oils for Heavy Duty Applications. Tribology International, 110, 23-34
Open this publication in new window or tab >>Fuel Consumption and Friction Benefits of Low Viscosity Engine Oils for Heavy Duty Applications
2017 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 110, p. 23-34Article in journal (Refereed) Published
Abstract [en]

One of the most attractive ways to tackle vehicle engine's inefficiencies is the use of Low Viscosity Engine Oils (LVEO). Adopted some decades ago for their use in the Ligh Duty segment, LVEO are now reaching the Heavy Duty segment.

In this study, a comparative fuel consumption test, where a LVEO performance is evaluated on an urban compressed natural gas buses fleet is portrayed. Then the friction performance of the same oils are studied on a Cameron-Plint tribometer, on an adapted twin disc tribometer to simulate journal bearing friction and on a Ball-on-Disc rig, using real engine parts in the former and the same set of engine oils used during the fleet test.

Results show a fuel consumption reduction in the fleet test and corresponding friction reduction in the tribometers when LVEO are used.

Place, publisher, year, edition, pages
Elsevier, 2017
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-61858 (URN)10.1016/j.triboint.2017.02.007 (DOI)000398871700003 ()2-s2.0-85012077599 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-02-21 (andbra)

Available from: 2017-02-07 Created: 2017-02-07 Last updated: 2018-09-13Bibliographically approved
Johansson, J., Devlin, M. & Prakash, B. (2015). Investigations into the occurrence of pitting in lubricated rolling four-ball tests (ed.). Paper presented at . Lubrication Science, 27(2), 103-126
Open this publication in new window or tab >>Investigations into the occurrence of pitting in lubricated rolling four-ball tests
2015 (English)In: Lubrication Science, ISSN 0954-0075, E-ISSN 1557-6833, Vol. 27, no 2, p. 103-126Article in journal (Refereed) Published
Abstract [en]

Pitting, a form of rolling contact fatigue, is a complex phenomenon and several factors influence its occurrence, particularly under lubricated conditions. In this work, studies have been conducted to observe the events that occur during lubricated rolling four-ball tests that may affect or eventually lead to the formation of pits. This is performed to form an understanding of the pit formation process. Included is tribofilm formation, surface degradation, wear mode, material changes and crack initiation sites. These investigations have been performed on the ball samples from rolling four-ball tests, conducted using two API GL-5 gear oils. The analyses revealed the formation of a low hardness region beneath the surface of the running track due to martensite decay. The formation rate and expansion of this region was found to differ for the two lubricating oils. The pitted balls also indicated that the initial fatigue cracks were initiated at or close to the surface

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-12493 (URN)10.1002/ls.1242 (DOI)000348516200003 ()2-s2.0-84921433642 (Scopus ID)ba65604e-ac45-4a44-9575-766c76e1a439 (Local ID)ba65604e-ac45-4a44-9575-766c76e1a439 (Archive number)ba65604e-ac45-4a44-9575-766c76e1a439 (OAI)
Note
Validerad; 2015; Nivå 2; 20131218 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Johansson, J. (2015). On the influence of gear oil properties on pitting life (ed.). (Doctoral dissertation). Paper presented at . : Luleå tekniska universitet
Open this publication in new window or tab >>On the influence of gear oil properties on pitting life
2015 (Swedish)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Increasing demands on the automotive industry to produce fuel-efficient vehicles has led the industry to explore different approaches, including reducing power losses and improving fuel efficiency of engines. The goal of this project has been to investigate the possibilities of reducing the frictional losses in drive axles and hypoid gears. In the literature, different ways of achieving low friction has been reported. However, before major changes can be made to commercial hypoid gear oils, a better understanding of their effect on the durability of transmission components has to be understood. The durability of gears includes many different failure modes. Macro-size contact fatigue (pitting) is one of the more commonly encountered and that ultimately limits the life of the components.In this work, experimental pitting life studies have been conducted using rolling four-ball and twin-disc test setups to analyse the impact of various gear oils’ physical and chemical properties on pitting during operation in the mixed lubrication regime. The results show that the frictional properties of the gear oils are the most significant in determining the pitting life. Enhancements in pitting life can be achieved in several ways, for example, by the choice of the base oil type, high viscosity oil, viscosity modifier type, and the tribofilms formed by anti-wear and extreme-pressure additives. Amongst these, all except high viscosity oils is compatible with the aim of reducing losses (load and load-independent losses). However, especially, the use of low friction type base oils or the low friction tribofilms formed by certain anti-wear and extreme-pressure additives have been found to be effective (with a slight preference for the latter) in improving pitting life. The results of these studies have been contained in five paper manuscripts and a brief gist of the work and salient results in each of these are briefly described below.Paper A: A range of different hypoid gear oils based on different base oils, viscosity levels, and friction modifying additives, were chosen for pitting studies. Each oil was characterized in terms of its physical properties and the pitting performance was analysed using a rolling four-ball test. The correlation between specific oil properties and pitting performance was analysed using multiple linear regression analysis.Paper B: In this, the used ball samples from tests with two of the oils tested in paper A were analysed to investigate the pit formation mechanisms. The worn surfaces and sub-surface materials revealed the differences in the behaviour of the two oils.Paper C. Based on the findings of paper A and B, a second batch of oils was prepared for investigations with a view to obtain low thin-film friction by the using different additives. The oils’ frictional behaviour was characterized in a ball-on-disc test rig. The pitting lives of two of these oils were measured using rolling four-ball tests and compared to two of the oils from paper A.Papers D and E: These two papers focussed on studies performed by using twin-disc rolling/sliding machine. The results confirmed that the trends and conclusions drawn from the rolling four-ball tests were relevant for gear contacts and enabled into optimising the gear oil formulation. Paper D deals with characterising of the frictional behaviour of several gear oils and identifying the two best performing formulations. In paper E, the pitting behaviour of the two oils has been analysed and compared to reference oil.

Place, publisher, year, edition, pages
Luleå tekniska universitet, 2015. p. 94
Series
Doctoral thesis / Luleå University of Technology 1 jan 1997 → …, ISSN 1402-1544
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-26057 (URN)c6141247-949a-4bcb-ad97-6545c3636e3e (Local ID)978-91-7583-315-6 (ISBN)978-91-7583-316-3 (ISBN)c6141247-949a-4bcb-ad97-6545c3636e3e (Archive number)c6141247-949a-4bcb-ad97-6545c3636e3e (OAI)
Note
Godkänd; 2015; 20150405 (jenjoh)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-01-10Bibliographically approved
Johansson, J., Devlin, M. & Prakash, B. (2014). Additive technology for improved pitting performande of mineral gear oils (ed.). Paper presented at ASIATRIB 2014 : Green Tribology 17/02/2014 - 20/02/2014. Paper presented at ASIATRIB 2014 : Green Tribology 17/02/2014 - 20/02/2014.
Open this publication in new window or tab >>Additive technology for improved pitting performande of mineral gear oils
2014 (English)Conference paper, Oral presentation only (Refereed)
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-38703 (URN)d2c22d6f-5e64-401a-b4a7-6aaf46affd48 (Local ID)d2c22d6f-5e64-401a-b4a7-6aaf46affd48 (Archive number)d2c22d6f-5e64-401a-b4a7-6aaf46affd48 (OAI)
Conference
ASIATRIB 2014 : Green Tribology 17/02/2014 - 20/02/2014
Note
Godkänd; 2014; 20140318 (andbra)Available from: 2016-10-03 Created: 2016-10-03 Last updated: 2018-01-14Bibliographically approved
Johansson, J., Devlin, M. T. & Prakash, B. (2014). Lubricant additives for improved pitting performance through a reduction of thin-film friction (ed.). Paper presented at . Tribology International, 80, 122-130
Open this publication in new window or tab >>Lubricant additives for improved pitting performance through a reduction of thin-film friction
2014 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 80, p. 122-130Article in journal (Refereed) Published
Abstract [en]

This paper describes an investigation into possibilities of enhancement of pitting lives of rolling components by using additive combinations with low thin-film friction. Various viscosity index improvers, anti-wear and extreme-pressure additive combinations were analysed in terms of their frictional behaviour, which in turn was compared to the oils pitting lives. For the pitting studies, a rolling four-ball test was employed. Friction was measured using a ball on disc machine as well as indirectly through “near contact” temperature measurements performed during rolling four-ball tests. The results show that additive combinations that result in low friction at the specific running condition can enhance pitting performance

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-9488 (URN)10.1016/j.triboint.2014.06.021 (DOI)000343391700014 ()2-s2.0-84905587945 (Scopus ID)821621e7-e123-4cc6-9790-fc88dc245673 (Local ID)821621e7-e123-4cc6-9790-fc88dc245673 (Archive number)821621e7-e123-4cc6-9790-fc88dc245673 (OAI)
Note
Validerad; 2014; 20140811 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Johansson, J., Devlin, M. T., Guevremont, J. M. & Prakash, B. (2013). Effects of gear oil properties on pitting life in rolling four-ball test configuration (ed.). Paper presented at . Tribology Transactions, 57(1), 104-113
Open this publication in new window or tab >>Effects of gear oil properties on pitting life in rolling four-ball test configuration
2013 (English)In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 57, no 1, p. 104-113Article in journal (Refereed) Published
Abstract [en]

There is a connection between the efficiency of oils and their wear and/or surface damage protective properties, an area not so well described in the literature. One such damage mode is macroscale contact fatigue on gear tooth flank surfaces, also called pitting. The present study is aimed at investigating the correlation between gear oils' physical properties, important in terms of gear transmission losses, and pitting life. Eight gear oils were formulated giving different combinations of base oil, viscosity, and concentration of friction modifiers. All eight oils also contained an additive package designed to meet GL-5 specifications. This study consists of three parts. In the first, the oils' physical properties were measured using a set of bench tests. In the second, the pitting lives of the oils were evaluated using rolling four-ball tests. The third part deals with the correlation between the measured physical properties of the oils and their pitting lives. This is achieved through multiple linear regression, with a view to finding the salient properties that have a significant influence on pitting life. The results show that gear oils' physical properties do have a large influence on the pitting lives. Oil properties that lower interfacial tangential stresses are beneficial in enhancing pitting life.

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-13507 (URN)10.1080/10402004.2013.856979 (DOI)000328929000012 ()2-s2.0-84890188964 (Scopus ID)cbb71067-8908-426d-91a9-8e57f4432333 (Local ID)cbb71067-8908-426d-91a9-8e57f4432333 (Archive number)cbb71067-8908-426d-91a9-8e57f4432333 (OAI)
Note
Validerad; 2013; 20140102 (andbra)Available from: 2016-09-29 Created: 2016-09-29 Last updated: 2018-07-10Bibliographically approved
Johansson, J., Devlin, M. & Prakash, B. (2012). Pit formation mechanisms in lubricated rolling four-ball tests (ed.). In: (Ed.), (Ed.), 15th Nordic Symposium on Tribology - NordTrib 2012: 12 - 15 June 2012 - Trondheim, Norway. Paper presented at Nordic Symposium on Tribology : 12/06/2012 - 15/06/2012. Trondheim: Department of Geography, Norwegian University of Science and Technology
Open this publication in new window or tab >>Pit formation mechanisms in lubricated rolling four-ball tests
2012 (English)In: 15th Nordic Symposium on Tribology - NordTrib 2012: 12 - 15 June 2012 - Trondheim, Norway, Trondheim: Department of Geography, Norwegian University of Science and Technology, 2012Conference paper, Published paper (Refereed)
Abstract [en]

Pitting due to rolling contact fatigue is a complex phenomenon and several factors influence its occurrence, particularly under lubricated conditions. A deeper understanding of pit formation mechanisms is needed in order to effectively evaluate the pitting behaviour of different lubricants. The present work focuses on investigating the events that lead to pit formation in the lubricated rolling four -ball test by analysing surface degradation, wear mode, material changes and crack initiation sites etc. These investigations have been conducted using two API - GL5 gear oils. These analyses of pitted balls revealed the formation of a low hardness region beneath the surface of the rolling track due to martensite decay. The formation rate and expans ion of this region was found to differ for the two lubricating oils. Examination of the pitted ball has also indicated that the initial rolling contact fatigue cracks were initiated at or close to the surface.

Place, publisher, year, edition, pages
Trondheim: Department of Geography, Norwegian University of Science and Technology, 2012
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-34748 (URN)9074e8ee-3a17-41b2-9dcb-6e5a66dae369 (Local ID)9074e8ee-3a17-41b2-9dcb-6e5a66dae369 (Archive number)9074e8ee-3a17-41b2-9dcb-6e5a66dae369 (OAI)
Conference
Nordic Symposium on Tribology : 12/06/2012 - 15/06/2012
Note
Godkänd; 2012; 20120830 (andbra)Available from: 2016-09-30 Created: 2016-09-30 Last updated: 2018-01-14Bibliographically approved
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