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Publications (10 of 37) Show all publications
Häggström, D., Sellgren, U. & Björklund, S. (2018). Evaluation of synchronizer loading parameters and their ability to predict failure. Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, 232(9), 1093-1104
Open this publication in new window or tab >>Evaluation of synchronizer loading parameters and their ability to predict failure
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 9, p. 1093-1104Article in journal (Refereed) Published
Abstract [en]

Molybdenum coated gearbox synchronizers are tested in a mu-comp test rig under varying loading conditions until failure. Four different parameters used to describe the thermomechanical load are evaluated just before failure to compare their ability to predict failure. The parameters evaluated are the synchronized kinetic energy, the synchronization power, and the focal as well as the average surface temperature increase. The focal surface temperature increase as well as the average surface temperature increase is found to predict failure with relatively good accuracy. It is shown that there exists a threshold which divides the synchronizer into either a very long or a very short service life. Additionally, a method to determine the average surface temperature in the gearbox management system is proposed.

Place, publisher, year, edition, pages
Sage Publications, 2018
Keywords
Sliding friction, sliding wear, boundary lubrication, synchronizer, gear shift, temperature, mu-comp
National Category
Manufacturing, Surface and Joining Technology
Identifiers
urn:nbn:se:kth:diva-234588 (URN)10.1177/1350650117738395 (DOI)000441984800004 ()2-s2.0-85044079759 (Scopus ID)
Funder
VINNOVA
Note

QC 20180914

Available from: 2018-09-14 Created: 2018-09-14 Last updated: 2018-10-24Bibliographically approved
Häggström, D., Sellgren, U. & Björklund, S. (2018). The effect of manufacturing tolerances on the thermomechanical load of gearbox synchronizers. In: : . Paper presented at 51st CIRP Conference on Manufacturing Systems, CIRP CMS 2018, 16 May 2018 through 18 May 2018 (pp. 1202-1207). Elsevier
Open this publication in new window or tab >>The effect of manufacturing tolerances on the thermomechanical load of gearbox synchronizers
2018 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Transmission performance is crucial for heavy trucks and connected vehicles in general and for platooning of trucks in particular. Gearbox synchronizers are highly loaded conical friction brakes used during gear shifts. Service life and, thus, the gear shifting reliability, of the synchronizer depend on the local thermomechanical loading of the contact surface. To achieve a robust and cost-efficient system, more knowledge is needed of how manufacturing tolerances affect the local thermomechanical loading and therefore service life and reliability of a synchronizer. The effects from angle deviations between the mating cones and cone out-of-roundness on focal maximum temperature during a synchronization sequence have been studied with transient thermomechanical simulations. It is shown that thermomechanical effects will significantly magnify the nominal effects on synchronization performance caused by shape deviations given by the specified manufacturing tolerances.

Place, publisher, year, edition, pages
Elsevier, 2018
Keywords
Gear shift, Manufacturing tolerances, Roundness, Synchronizer, Thermomechanical, Automobiles, Fits and tolerances, Gears, Synchronization, Trucks, Vehicle transmissions, Gear-shifts, Thermo-mechanical, Gear manufacture
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:kth:diva-236388 (URN)10.1016/j.procir.2018.03.050 (DOI)2-s2.0-85049591381 (Scopus ID)
Conference
51st CIRP Conference on Manufacturing Systems, CIRP CMS 2018, 16 May 2018 through 18 May 2018
Note

QC 20181101

Available from: 2018-11-01 Created: 2018-11-01 Last updated: 2018-11-01Bibliographically approved
Lundberg, O., Finnveden, S., Björklund, S., Pärssinen, M. & Lopez Arteaga, I. (2015). A nonlinear state-dependent model for vibrations excited by roughness in rolling contacts. Journal of Sound and Vibration, 345(9), 197-213
Open this publication in new window or tab >>A nonlinear state-dependent model for vibrations excited by roughness in rolling contacts
Show others...
2015 (English)In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 345, no 9, p. 197-213Article in journal (Refereed) Published
Abstract [en]

A state-dependent method to model contact nonlinearities in rolling contacts is proposed. By pre-calculation of contact stiffness and contact filters as functions of vertical relative displacement, a computationally efficient modelling approach based on a moving point force description is developed. Simulations using the state-dependent model have been analysed by comparison with measurements. Results from the investigated case consisting of a steel ball rolling over a steel beam having two different degrees of roughness - show good agreement between nonlinear simulations and measured beam vibrations. The promising results obtained with the proposed method are potentially applicable to wheel rail interaction and rolling element bearings.

National Category
Vehicle Engineering
Identifiers
urn:nbn:se:kth:diva-155193 (URN)10.1016/j.jsv.2015.02.010 (DOI)000350998800013 ()2-s2.0-84924514876 (Scopus ID)
Note

QC 20150507. Updated from submitted to published.

Available from: 2014-11-03 Created: 2014-11-03 Last updated: 2017-12-05Bibliographically approved
Häggström, D., Stenström, W., Sellgren, U. & Björklund, S. (2015). A Verified and Validated Model for Simulation-Driven Design of Heavy Duty Truck Synchronizers. In: ASME Proceedings | ASME 2015 Power Transmission and Gearing Conference: . Paper presented at ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC/CIE 2015, Boston, United States, 2 August 2015 through 5 August 2015. ASME Press, 10, Article ID V010T11A045.
Open this publication in new window or tab >>A Verified and Validated Model for Simulation-Driven Design of Heavy Duty Truck Synchronizers
2015 (English)In: ASME Proceedings | ASME 2015 Power Transmission and Gearing Conference, ASME Press, 2015, Vol. 10, article id V010T11A045Conference paper, Published paper (Refereed)
Abstract [en]

The strong market trend toward lower fuel consumption for heavy road transports requires more frequent gear shifting and increased gear shift performance, i.e. shorter shift time. Increased shift performance means higher loads for the synchronizer which brings component and shifting process optimization more into focus.

Traditionally, synchronizer development has relied on physical testing of complete synchronizers in general gearbox test rigs or in specialized synchronization test rigs leaving much of the causes of the observed effects unclear. This paper presents a generalized FE-based thermomechanical simulation model to be used for model-based synchronizer analysis and design. The model is targeted for studies of how different external loads and the values of different synchronizer design parameters affect the temperature transient in the friction lining. Recommendations of how major modeling complications should be treated are presented. The developed simulation model is verified and validated with a combination of analytical means and transient temperature measurements of bulk and surface temperatures. The applicability of the presented model, as well as its limitations, are discussed and exemplified with different design cases.

Place, publisher, year, edition, pages
ASME Press, 2015
Keywords
Atmospheric temperature, Gears, Optimization, Reliability analysis, Stress analysis, Synchronization, Temperature measurement
National Category
Vehicle Engineering
Identifiers
urn:nbn:se:kth:diva-182350 (URN)10.1115/DETC2015-47318 (DOI)000380413500045 ()2-s2.0-84979008641 (Scopus ID)978-0-7918-5720-5 (ISBN)
External cooperation:
Conference
ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, IDETC/CIE 2015, Boston, United States, 2 August 2015 through 5 August 2015
Note

QC 20160218

Available from: 2016-02-18 Created: 2016-02-18 Last updated: 2018-10-24Bibliographically approved
Sosa, M., Björklund, S., Sellgren, U. & Olofsson, U. (2015). In situ surface characterization of running-in of involute gears. Wear, 340-341, 41-46
Open this publication in new window or tab >>In situ surface characterization of running-in of involute gears
2015 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 340-341, p. 41-46Article in journal (Refereed) Published
Abstract [en]

Gear life and operation are largely determined by the properties of the contacting surfaces, which inevitably change over the gear life. The initial topography transformation, a characteristic effect of running-in, is very important. This paper focuses on how the running-in of the surface topography can be characterized and what methodology can be used for this purpose. To characterize running-in, gears were run in an FZG back-to-back test rig and the changes in surface topography were measured in situ using a Form Talysurf Intra. This enables the same gear tooth surface to be measured with enough precision to follow its development through the different stages of running-in. Gear tooth surfaces as manufactured were measured on three occasions: in initial manufactured condition, after a standard running-in procedure, and after an efficiency test. Running-in was characterized both qualitatively by plotting roughness profiles and quantitatively by analyzing a selected set of roughness parameters. This paper demonstrates that: the asperity peaks were worn off in the initial running-in stage; roughness, waviness, and form can be separated using a carefully chosen polynomial fit and the Gaussian filter; surface topography can be examined initially, after running-in, and after operation in situ; and complete wear of the initial surface can be observed in specific circumstances.

Keywords
Gear manufacture, Gear teeth, Gears, Topography, Back-to-back tests, Contacting surfaces, Different stages, Form removal, Gear tooth surface, In-situ surface characterizations, Roughness parameters, Running-in, Surface topography
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-173897 (URN)10.1016/j.wear.2015.03.008 (DOI)000362926400007 ()2-s2.0-84925742642 (Scopus ID)
Note

QC 20170928

Available from: 2015-09-22 Created: 2015-09-22 Last updated: 2017-09-28Bibliographically approved
Häggström, D., Stenström, W., Sellgren, U. & Björklund, S. (2015). Parameter study of the thermomechanical performance of heavy duty synchronizers. In: 15th International VDI Congress: . Paper presented at 15th International VDI Congress–Drivetrain for Commercial Vehicles 2015, June 16-17, Friedrichshafen, Germany.
Open this publication in new window or tab >>Parameter study of the thermomechanical performance of heavy duty synchronizers
2015 (English)In: 15th International VDI Congress, 2015Conference paper, Published paper (Refereed)
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-182214 (URN)
Conference
15th International VDI Congress–Drivetrain for Commercial Vehicles 2015, June 16-17, Friedrichshafen, Germany
Note

NQC 20160218

Available from: 2016-02-18 Created: 2016-02-18 Last updated: 2018-10-24Bibliographically approved
Andersson, M., Björklund, S., Sellgren, U. & Olofsson, U. (2014). A study of the influence of gear surface roughness and immersion depth on gear efficiency and temperature. In: Proceedings of the 16th Nordic Symposium on Tribology - NORDTRIB 2014: . Paper presented at The 16th Nordic Symposium on Tribology - NORDTRIB 2014, 10-13 JUNE 2014, Aarhus, Denmark (pp. A 1-A 6).
Open this publication in new window or tab >>A study of the influence of gear surface roughness and immersion depth on gear efficiency and temperature
2014 (English)In: Proceedings of the 16th Nordic Symposium on Tribology - NORDTRIB 2014, 2014, p. A 1-A 6Conference paper, Published paper (Refereed)
Keywords
gear, temperature, efficiency
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Identifiers
urn:nbn:se:kth:diva-153015 (URN)
Conference
The 16th Nordic Symposium on Tribology - NORDTRIB 2014, 10-13 JUNE 2014, Aarhus, Denmark
Funder
Swedish Energy Agency
Note

QC 20141006

Available from: 2014-10-02 Created: 2014-10-02 Last updated: 2018-01-11Bibliographically approved
Lundberg, O., Finnveden, S., Lopez Arteaga, I. & Björklund, S. (2014). Non-linear contact stiffness and dynamic contact filter for rolling contacts. In: FISITA 2014 World Automotive Congress - Proceedings: . Paper presented at 35th FISITA World Automotive Congress, 2014, 2 June 2014 through 6 June 2014. FISITA
Open this publication in new window or tab >>Non-linear contact stiffness and dynamic contact filter for rolling contacts
2014 (English)In: FISITA 2014 World Automotive Congress - Proceedings, FISITA , 2014Conference paper, Published paper (Refereed)
Abstract [en]

Rolling contacts present in passenger cars such as in bearings and transmission elements are sources of noise and vibration, principally for interior comfort concerns. Moreover, tyre/road noise is the main source of road traffic noise which in turn leads to sleep disturbance and annoyance. In order to simulate friction losses as well as generated noise and vibrations in any rolling contact, it is crucial to have a correct description of the dynamic excitation caused by the roughness of the surfaces in contact. In this paper, a state-dependent modelling approach previously proposed by the authors is applied to a well-defined steel-steel rolling contact. A parametric study investigating the influence of rolling speed on contact conditions is performed, indicating the limits for the use of linear point force expressions for the rolling contact investigated. The state-dependent method is based on pre-calculation of contact stiffness and contact filtering as functions of vertical relative displacement. This leads to a computationally efficient way to include the influence of surface roughness and shape of the contacting bodies in a point force expression. Only vertical contact forces are studied within the scope of this work. Tangential friction forces are likely to affect the resulting vibrations and should therefore be further studied. 

Place, publisher, year, edition, pages
FISITA, 2014
Keywords
Contact, Rolling, Roughness, State-dependent, Vibration, Contacts (fluid mechanics), Noise pollution, Rolling resistance, Stiffness, Computationally efficient, Dynamic excitations, Noise and vibration, Non-linear contact stiffness, Relative displacement, Tangential friction force, Surface roughness
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-246648 (URN)2-s2.0-85060470126 (Scopus ID)
Conference
35th FISITA World Automotive Congress, 2014, 2 June 2014 through 6 June 2014
Note

QC 20190619

Available from: 2019-06-19 Created: 2019-06-19 Last updated: 2019-06-19Bibliographically approved
Häggström, D., Sellgren, U. & Björklund, S. (2014). Robust pre-synchronization in heavy truck transmissions. In: International Gear Conference 2014: 26th–28th August 2014, Lyon. Paper presented at International Gear Conference 2014, 26th–28th August 2014, Lyon, France (pp. 914-923). Woodhead Publishing Limited
Open this publication in new window or tab >>Robust pre-synchronization in heavy truck transmissions
2014 (English)In: International Gear Conference 2014: 26th–28th August 2014, Lyon, Woodhead Publishing Limited, 2014, p. 914-923Conference paper, Published paper (Refereed)
Abstract [en]

Transmission performance directly influences vehicle behaviour, energy efficiency, and perceived quality. A modern transmission is an aggregate of interacting sub-systems, e. g. gears, bearings, synchronisers and other shifting elements. New transmission trends ask for increased shift performance with higher loads for the synchronising components. Synchroniser development has traditionally required exhaustive physical testing and few analytical methods exist. A numerical method for assessing pre-synchronisation performance, using a multi-physics FEM software, is presented. Simulations show that grooves in the synchroniser surface have a positive effect on pre-synchronisation, and that the presence of grooves seems to be more important than the groove design.

Place, publisher, year, edition, pages
Woodhead Publishing Limited, 2014
National Category
Materials Engineering
Identifiers
urn:nbn:se:kth:diva-160811 (URN)10.1533/9781782421955.914 (DOI)000348383200092 ()978-1-78242-195-5 (ISBN)978-1-78242-194-8 (ISBN)
Conference
International Gear Conference 2014, 26th–28th August 2014, Lyon, France
Note

QC 20150227

Available from: 2015-02-27 Created: 2015-02-27 Last updated: 2018-10-24Bibliographically approved
Sosa, M., Björklund, S. & Sellgren, U. (2013). Gear Web Design with focus on Powder Metal - Sound characteristics and web design: Sound characteristics  and web design. In: International Conference on Gears: Europe invites the world : time and venue: October 7th to 9th, 2013, Technical University of Munich (TUM), Garching (near Munich), Germany. Paper presented at 2013 International Conference on Gears 2013, October 7th to 9th, 2013, Germany (pp. 1199-1208). VDI Verlag, 2
Open this publication in new window or tab >>Gear Web Design with focus on Powder Metal - Sound characteristics and web design: Sound characteristics  and web design
2013 (English)In: International Conference on Gears: Europe invites the world : time and venue: October 7th to 9th, 2013, Technical University of Munich (TUM), Garching (near Munich), Germany, VDI Verlag , 2013, Vol. 2, p. 1199-1208Conference paper, Published paper (Refereed)
Abstract [en]

The presented work focuses on gear web design using powder metal (PM) by utilizing the finite element method (FEM) to reduce weight and inertia taking into account root bending strength and tooth deflection.A topological optimization is used to determine feasible candidates for different web designs which have as objective to reduce volume. Similar geometric topologies were shown during different loading conditions; and hence, this topology was chosen as a suitable candidate. This candidate was further developed into a parametric model which incorporated the same overall shape shown in the topological optimization. A shape optimization procedure was used utilizing the parametric model having as state variables root bending strength and tooth deflection; and as objective the decrease in inertia, and in consequence weight, of the gear. To analyze a gear which is thoroughly studied, a similar gear to the FZG C type gear is used.Another aspect studied in this paper is the damping properties of three different gears, wrought, conventional PM and double density. Their damping properties are measured using their reverberation time and their frequency response function.Sound characteristics results show that a significant increase in dampening can be observed in PM gears when compared to conventional wrought gears. Finally results from the shape optimizations show how gears can be designed with PM to reduce weight and inertia, with marginal effects on strength and stiffness.

Place, publisher, year, edition, pages
VDI Verlag, 2013
Keywords
gear web, powder metal, stiffness
National Category
Other Mechanical Engineering
Research subject
Machine Design
Identifiers
urn:nbn:se:kth:diva-161352 (URN)978-3-18-092199-0 (ISBN)
Conference
2013 International Conference on Gears 2013, October 7th to 9th, 2013, Germany
Note

QC 20150312

Available from: 2015-03-11 Created: 2015-03-11 Last updated: 2015-03-12Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-2578-9453

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