Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Optimization of synchronizer cone angle with regards tomanufacturing tolerances of cone roundness and cone angle
KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).ORCID-id: 0000-0002-6644-7441
KTH, Skolan för industriell teknik och management (ITM).ORCID-id: 0000-0002-9857-8091
KTH, Skolan för industriell teknik och management (ITM), Maskinkonstruktion (Inst.).ORCID-id: 0000-0002-2578-9453
(engelsk)Manuskript (preprint) (Annet vitenskapelig)
Abstract [en]

The effects from manufacturing tolerances on the maximum focal temperature has been investigated by transient thermomechanical simulations. Both relative cone angle and cone out-of-roundness for molybdenum and carbon fiber reinforced polymer (CFRP) synchronizers were evaluated. It was shown that cone out-of-roundness significantly increase the focal contact temperature for that specific cone, but has little impact on the opposing cone. Two populations of measured synchronizers were evaluated, and it was shown that the maximum focal surface temperature can be decreased in almost all tolerance cases by introducing a relative angle between the cones.

HSV kategori
Identifikatorer
URN: urn:nbn:se:kth:diva-237232OAI: oai:DiVA.org:kth-237232DiVA, id: diva2:1258165
Merknad

QC 20181112

Tilgjengelig fra: 2018-10-24 Laget: 2018-10-24 Sist oppdatert: 2022-09-09bibliografisk kontrollert
Inngår i avhandling
1. Towards model-based development of heavy truck synchronizers
Åpne denne publikasjonen i ny fane eller vindu >>Towards model-based development of heavy truck synchronizers
2018 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Gear shifts are becoming more and more important as engines are adapted to low speed and high torque working conditions. Synchronizers are key components for successful gear shifts. To adapt the synchronizers to future engines and thus new working conditions, improved development tools are needed. This thesis includes a comprehensive gear shift and synchronizer frame of reference section with detailed explanations of how a synchronizer works. The thesis also presents two types of numerical models that enable design analyses of the synchronization process.

Fluid-structure interaction models were used to simulate oil evacuation between the synchronizer cones to assess the synchronizer performance during the pre-synchronization phase. For the main synchronization phase, thermomechanical finite element models were used to simulate the transient temperature in the synchronizer contact surfaces. To verify and validate the thermomechanical simulations, both bulk and surface temperature measurements were used, as well as a qualitative comparison of the position of initial wear marks relative to the position of high surface temperature areas in the simulation. The validated thermomechanical model was used to predict failure in molybdenum coated synchronizers. It was shown that the simulated temperature is a better predictor of synchronizer failure than the commonly used parameters “synchronization energy” and “synchronization power”.

A methodology to develop friction models based on sliding speed, contact pressure and surface temperature was developed, and applied for a molybdenum coated synchronizer.

To allow for improved accuracy of carbon fiber reinforced polymer (CFRP) lined synchronizer simulations, material data for a CFRP friction lining was estimated with different test methods. A contact surface temperature threshold where a reduction in coefficient of friction, accelerated wear and formation of hot spots starts was identified.

To reduce the maximum surface temperature, a relative angle between the cone contact surfaces can be introduced. The optimum relative cone angle was determined based on measured geometric deviations for a population of manufactured synchronizers. It was shown that there is an optimum relative cone angle that significantly can reduce the maximum surface temperature during synchronization.

sted, utgiver, år, opplag, sider
KTH Royal Institute of Technology, 2018. s. 94
Serie
TRITA-ITM-AVL ; 2018:51
Emneord
synchronization, synchronizers, gear shift, gearbox
HSV kategori
Identifikatorer
urn:nbn:se:kth:diva-237235 (URN)978-91-7873-002-5 (ISBN)
Disputas
2018-11-22, Gladan (B319), Brinellvägen 85, holm, 10:00 (engelsk)
Opponent
Veileder
Forskningsfinansiär
VINNOVA, 2112-04619
Tilgjengelig fra: 2018-10-24 Laget: 2018-10-24 Sist oppdatert: 2022-09-09bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Person

Häggström, DanielSellgren, UlfBjörklund, Stefan

Søk i DiVA

Av forfatter/redaktør
Häggström, DanielSellgren, UlfBjörklund, Stefan
Av organisasjonen

Søk utenfor DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric

urn-nbn
Totalt: 52 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf