Change search
Link to record
Permanent link

Direct link
BETA
Sellgren, Ulf
Publications (10 of 23) Show all publications
Bergseth, E., Henriksson, M., Dizdar, S. & Sellgren, U. (2019). Effects of thrust washer bearing surface characteristics on planetary gear train wear. Wear, 432-433, Article ID 202933.
Open this publication in new window or tab >>Effects of thrust washer bearing surface characteristics on planetary gear train wear
2019 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 432-433, article id 202933Article in journal (Refereed) Published
Abstract [en]

Thrust washers in spur planetary gears are placed between the planet wheel and planet carrier and act as spacers and wear pads. Metal to metal sliding contact between the planet wheel – washer – carrier causes frictional power losses that, combined with starved lubrication, may cause high contact temperatures and thermo-mechanical effects that potentially trigger thermo-elastic instabilities and excessive local wear. The planetary gear system would benefit from a low-friction interface between the washer and the planet wheel. Five washers with different surface treatments were tested in a full-scale gear rig. These tests were also replicated as closely as possible in a pin-on-disc tribometer. The following types of finishing material treatments were studied: a chemical nickel coating plus polymer on a nitro-carburised surface, a combination of nitro-carburization and solid lubricant layers, electroless deposited chemical nickel coating plus polymer, nitro-carburizing, and manganese phosphating. The frictional results indicate that tribometer tests can be used to compare and classify new washer materials. Lab scale tests show that a new experimental self-lubricating tribomaterial that was applied with laser cladding has a promising potential to increase planetary gear train robustness and service life, especially if the surface is fine grinded.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Thrust washers, Planetary gears, Adhesive wear, Surface treatment, Laser cladding
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Transport Science; Machine Design
Identifiers
urn:nbn:se:kth:diva-258028 (URN)10.1016/j.wear.2019.202933 (DOI)000477874700023 ()2-s2.0-85067419223 (Scopus ID)
Funder
Swedish Foundation for Strategic Research , SM15-0025
Note

QC 20191007

Available from: 2019-09-09 Created: 2019-09-09 Last updated: 2019-10-11Bibliographically approved
Williamsson, D., Sellgren, U. & Söderberg, A. (2019). Product architecture transition in a modular cyber-physical truck. Journal of Computing and Information Science in Engineering, 19(3), Article ID 031002.
Open this publication in new window or tab >>Product architecture transition in a modular cyber-physical truck
2019 (English)In: Journal of Computing and Information Science in Engineering, ISSN 1530-9827, E-ISSN 1944-7078, Vol. 19, no 3, article id 031002Article in journal (Refereed) Published
Abstract [en]

A modular product architecture is a strategic means to deliver external variety and internal commonality. In this paper, we propose a new clustering-based method for product modularization that integrates product complexity and company business strategies. The proposed method is logically verified by a studied industrial case, where the architecture of a heavy truck driveline is analyzed in terms of how it has evolved over a couple of decades, due to changed business strategies and the evolution of new technology. The presented case indicates that the new methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company-specific strategies. Furthermore, the case study clearly shows that the business strategic reasons for a specific architecture can be found by analyzing how sensitive the clusters are to changes in the module drivers (MD). © 2019 by ASME.

Place, publisher, year, edition, pages
American Society of Mechanical Engineers (ASME), 2019
Keywords
business strategy, clustering, complexity, DSM, integrated modularization, MFD, product architecting, Cyber Physical System, Modular construction, Strategic planning, Trucks, Modularizations, Architecture
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-252515 (URN)10.1115/1.4042961 (DOI)2-s2.0-85063151382 (Scopus ID)
Note

QC 20190710

Available from: 2019-07-10 Created: 2019-07-10 Last updated: 2019-07-10Bibliographically approved
Andersson, K., Hagnestål, A. & Sellgren, U. (2018). A flexible chain proposal for winch based point absorbers. In: Proceedings of the ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2018: August 26-29, 2018, Quebec City, Quebec, Canada. Paper presented at ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference.
Open this publication in new window or tab >>A flexible chain proposal for winch based point absorbers
2018 (English)In: Proceedings of the ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference IDETC/CIE 2018: August 26-29, 2018, Quebec City, Quebec, Canada, 2018Conference paper, Published paper (Refereed)
Abstract [en]

Ocean wave power is a promising renewable energy source for future energy production. It has however been difficult to find a cost-effective solution to convert the wave energy into electricity. The harsh marine environment and the fact that wave power is delivered with high forces at low speeds makes design of durable mechanical structures and efficient energy conversion challenging. The dimensioning forces strongly depend on the wave power concept, the Wave Energy Converter (WEC) implementation and the actual Power TakeOff (PTO) system. A WEC using a winch as a Power Take-Off system, i.e. a Winch Based Point Absorber (WBPA), could potentially accomplish a low Levelized Cost Of Energy (LCOE) if akey component - a low-cost, durable and efficient winch that can deal with high loads - can be developed. A key problem for achieving a durable winch is to find a force transmitting solution that can deal with these high loads and handle up to 80 million cycles. In this article we propose a design solution for a force transmitting chain in a WBPA system where elastomeric bearings are used as a means to achieve the relative motion between the links in the chain. With this solution no sliding is present and the angular motion is achieved as a deformation in the elastomeric bearing when the chain is winded on a drum. The link was designed primarily to minimize the number of joints in the chain: Thereby the maximum allowed relative angle between the links when rolled up over the drum should be as large as possible within practical limits. The angle is to be handled by the elastomeric bearing. A detailed strength analysis of the link has been performed as well as topology optimization to increase the strength to weight ratio. A test rig for a first proof of concept testing has been developed and the first preliminary test results indicate that this concept with using elastomeric bearings can be a potential solution for a durable chain and should be analyzed further for fatigue conditions and under water operations. 

Keywords
Chain transmission; Elastomeric bearing; Power take-off system; Wave power
National Category
Energy Engineering
Identifiers
urn:nbn:se:kth:diva-240567 (URN)000461131000020 ()2-s2.0-85056899645 (Scopus ID)
Conference
ASME 2018 International Design Engineering Technical Conferences & Computers and Information in Engineering Conference
Note

QC 20190107

Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2019-04-26Bibliographically approved
Williamsson, D., Sellgren, U. & Söderberg, A. (2018). A Hunt For the Hidden Reasons Behind a Product Architecture. In: DS 96: The 20th International DSM Conference: . Paper presented at The 20th International DSM Conference (pp. 93-103). The Design Society
Open this publication in new window or tab >>A Hunt For the Hidden Reasons Behind a Product Architecture
2018 (English)In: DS 96: The 20th International DSM Conference, The Design Society , 2018, p. 93-103Conference paper, Published paper (Refereed)
Abstract [en]

A modular product architecture is a strategic means to deliver external variety and internal commonality. In this paper, a heavy duty modular gearbox architecture is represented and analyzed. In focus is re-engineering of hidden technical complexity and business strategy concerns behind an existing product architecture. The architecture of the investigated gearbox is represented and analyzed with a Product Architecture DSM and the Integrated Modularization Method (IMM). Furthermore, a Cluster Match Matrix (CMM) is proposed as a means to compare multiple clustering results. The case study indicates that the IMM methodology and CMM can be used for analyzing and finding the explicit and/or implicit reason for a targeted existing product architecture.

Place, publisher, year, edition, pages
The Design Society, 2018
Keywords
Product Architecting, Integrated Modularization, DSM, MFD, IMM
National Category
Other Mechanical Engineering
Research subject
Machine Design
Identifiers
urn:nbn:se:kth:diva-244473 (URN)2-s2.0-85060640270 (Scopus ID)
Conference
The 20th International DSM Conference
Note

QC 20190306

Available from: 2019-02-21 Created: 2019-02-21 Last updated: 2019-03-18Bibliographically approved
Törngren, M. & Sellgren, U. (2018). Complexity challenges in development of cyber-physical systems. In: Marten Lohstroh, Patricia Derler, Marjan Sirjani (Ed.), Principles of modeling: Essays dedicated to Edward A. Lee on the occasion of his 60th birthday (pp. 478-503). Switzerland: Springer
Open this publication in new window or tab >>Complexity challenges in development of cyber-physical systems
2018 (English)In: Principles of modeling: Essays dedicated to Edward A. Lee on the occasion of his 60th birthday / [ed] Marten Lohstroh, Patricia Derler, Marjan Sirjani, Switzerland: Springer, 2018, p. 478-503Chapter in book (Refereed)
Abstract [en]

In embarking towards Cyber-Physical Systems (CPS) withunprecedented capabilities it becomes essential to improve our understanding ofCPS complexity and how we can deal with it. We investigate facets of CPScomplexity and the limitations of Collaborating Information Processing Systems(CIPS) in dealing with those facets. By CIPS we refer to teams of humans andcomputer-aided engineering systems that are used to develop CPS. Furthermore,we specifically analyze characteristic differences among software and physicalparts within CPS. The analysis indicates that it will no longer be possible to relyonly on architectures and skilled people, or process and model/tool centeredapproaches. The tight integration of heterogeneous physical, cyber, CPS components,aspects and systems, results in a situation with interfaces and interrelationseverywhere, each requiring explicit consideration. The role of modelbasedand computer aided engineering will become even more essential, anddesign methodologies will need to deeply consider interwoven systems andsoftware aspects, including the hidden costs of software.

Place, publisher, year, edition, pages
Switzerland: Springer, 2018
Keywords
cyber-physical systems, complex systems, complexity, complexity management, systems engineering, software engineering
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:kth:diva-236313 (URN)10.1007/978-3-319-95246-8_27 (DOI)2-s2.0-85052709637 (Scopus ID)978-3-319-95245-1 (ISBN)978-3-319-95246-8 (ISBN)
Note

QC 20181019

Available from: 2018-10-17 Created: 2018-10-17 Last updated: 2019-05-03Bibliographically approved
Andersson, K., Hagnestål, A. & Sellgren, U. (2018). Design of a flexible chain for winch based point absorbers. In: Proceedings of NordDesign: Design in the Era of Digitalization, NordDesign 2018: . Paper presented at 13th Biennial NordDesign 2018.
Open this publication in new window or tab >>Design of a flexible chain for winch based point absorbers
2018 (English)In: Proceedings of NordDesign: Design in the Era of Digitalization, NordDesign 2018, 2018Conference paper, Published paper (Refereed)
National Category
Ocean and River Engineering
Identifiers
urn:nbn:se:kth:diva-240563 (URN)2-s2.0-85057143261 (Scopus ID)
Conference
13th Biennial NordDesign 2018
Note

QC 20190107

Available from: 2018-12-19 Created: 2018-12-19 Last updated: 2019-04-09Bibliographically approved
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
Sellgren, U. & Williamsson, D. (2018). Modularisation and product description: a review and a focused case.
Open this publication in new window or tab >>Modularisation and product description: a review and a focused case
2018 (English)Report (Other academic)
Abstract [en]

This technical report contains the results from the first step of a Ph.D. project in the field of modularisation and product description, conducted by the author at Scania CV AB in Södertälje and at KTH Royal Institute of Technology in Stockholm.Scania is one of the leading truck, bus and engine manufacturers in the world and is today a part of the Volkswagen (VW) Group AG, which is one of the world’s largest vehicle manufacturing groups. Scania has a successful history in vehicle modularisation and claims it is one of the most important reasons why they are a leading company today. Scania also has a unique way of describing the modular product in their generic product structure, in order to efficiently describe the many product variants. However, the Scania product has over the last years been developed into a mechatronic product with embedded software in focus, demanding the product description as well as the modularisation methodology to support this new dimension. Collaboration within the Volkswagen group also makes it even more important to understand and explain “The Scania Way” of modularising and describing the product.The purpose of the study presented in this technical reports was to investigate the present state at Scania, concerning product architecting, modularisation, product description and configuration. Hence, this report contains a literature review, a case study based on semi-structured interviews, as well as an architecture analysis of some main Scania components. The analysed main components were chosen to both include mechanical, electrical and software disciplines, in order to highlight some of the challenges when modularising and describing a high-performing product configured from heterogeneous technologies that are developed and managed multidisciplinary. Another purpose of the report was to answer the research questions; what is the present state at Scania, regarding product architecture and management of product data? And what are the unique properties in the modular product architecture at Scania and how are they used, developed and maintained?The result of the analysis indicates that the nomenclature needs to be further defined at Scania, preferably with a definition which is consistent in order to reduce the risk of confusion and design mistakes during future collaborations. Scania strives to maximise the number of product variants (external variety), while keeping the number of technical solutions low (internal commonality). Hence, a structured methodology which supports the development of the product architecture is clearly needed at Scania, in order to make future collaborations as efficient and successful as possible, and to control the increasing technical complexity in the future Cyber-Physical Systems. Finally, configuration rules are identified to be highly important in order to successfully realise a modular product architecture, since the architecture normally will not be fully uncoupled. A drawback with this approach is that the solution space (i.e. all valid configurations) becomes extremely hard to identify, therefore an advanced product description methodology is essential.

Publisher
p. 77
Series
TRITA-ITM-AVL ; 2018:5
Keywords
Modularisation, Product Description, Module, Product Structure, Product Architecture
National Category
Other Mechanical Engineering
Research subject
Machine Design
Identifiers
urn:nbn:se:kth:diva-236093 (URN)
Note

QC 20181019

Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2019-02-22Bibliographically approved
Williamsson, D., Sellgren, U. & Söderberg, A. (2018). Product Architecture Transition in a Modular Cyber-Physical Truck. In: ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference: . Paper presented at 38th Computers and Information in Engineering Conference. ASME Press, Volume 1A, Article ID DETC2018-85364.
Open this publication in new window or tab >>Product Architecture Transition in a Modular Cyber-Physical Truck
2018 (English)In: ASME 2018 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, ASME Press, 2018, Vol. Volume 1A, article id DETC2018-85364Conference paper, Published paper (Refereed)
Abstract [en]

A modular product architecture is a strategic means to deliver external variety and internal commonality. In this paper, we propose a new clustering based method for product modularization that integrates product complexity and company business strategies. The proposed method is logically verified by a studied industrial case, where the architecture of a heavy truck driveline is analyzed in terms of how it has evolved over a couple of decades, due to changed business strategies and the evolution of new technology. The presented case indicates that the new methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company-specific strategies. Furthermore, the case study clearly shows that the business strategic reasons for a specific architecture can be found by analyzing how sensitive the clusters are to changes in the module drivers.

Place, publisher, year, edition, pages
ASME Press, 2018
Keywords
Business Strategy, Clustering, Complexity, DSM, Integrated Modularization, MFD, Product Architecting
National Category
Other Mechanical Engineering
Research subject
Machine Design
Identifiers
urn:nbn:se:kth:diva-244470 (URN)10.1115/DETC2018-85364 (DOI)2-s2.0-85056863711 (Scopus ID)9780791851722 (ISBN)
Conference
38th Computers and Information in Engineering Conference
Available from: 2019-02-21 Created: 2019-02-21 Last updated: 2019-02-22Bibliographically approved
Williamsson, D., Sellgren, U. & Söderberg, A. (2018). Product architecture transition in an evolving multi-brand organisation. In: Proceedings of International Design Conference, DESIGN: . Paper presented at 15th International Design Conference, DESIGN 2018; Dubrovnik; Croatia; 21 May 2018 through 24 May (pp. 929-940). Glasgow
Open this publication in new window or tab >>Product architecture transition in an evolving multi-brand organisation
2018 (English)In: Proceedings of International Design Conference, DESIGN, Glasgow, 2018, p. 929-940Conference paper, Published paper (Refereed)
Abstract [en]

A modular architecture is a strategic means to deliver external variety and internal commonality. A methodology for product modularization that integrates complexity and strategies is proposed and logically verified with an industrial case from the heavy truck business area. The case study indicates that the new methodology is capable of identifying and proposing reasonable module candidates that address product complexity as well as company specific strategies.

Place, publisher, year, edition, pages
Glasgow: , 2018
Keywords
Product architecture, Design Structure Matrix (DSM), Variant management, Characteristics and properties
National Category
Other Mechanical Engineering
Research subject
Machine Design
Identifiers
urn:nbn:se:kth:diva-244469 (URN)10.21278/idc.2018.0366 (DOI)2-s2.0-85054955972 (Scopus ID)9789537738594 (ISBN)
Conference
15th International Design Conference, DESIGN 2018; Dubrovnik; Croatia; 21 May 2018 through 24 May
Note

QC 20190316

Available from: 2019-02-21 Created: 2019-02-21 Last updated: 2019-03-06Bibliographically approved
Organisations

Search in DiVA

Show all publications