Evaluation of synchronizer loading parameters and their ability to predict failure

Abstract

Molybdenum coated gearbox synchronizers are tested in a μ-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.

Keywords

Sliding friction sliding wear boundary lubrication synchronizer gear shift temperature

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References

Socin RJ and Walters LK. Manual transmission synchronizers. SAE paper 680008, 1968.

Christoffer U. Efficient synchroniser for comfort and performance increase of manual and dual clutch transmissions. In: 15th international Congress and expo, CTI symposium, automotive transmissions, HEV and EV drives, Berlin, Germany, 5–8 December 2016.

Häggström D. On synchronization of heavy truck transmissions. Licentiate thesis, KTH Royal Institute of Technology, Sweden, 2016.

Zagrodzki

. Thermoelastic instability in friction clutches and brakes–transient modal analysis revealing mechanisms of excitation of unstable modes. Int J Solids Struct 2009; 46: 2463–2476.

Häggström D, Stenström W, Sellgren U, et al. Parameter study of the thermomechanical performance of heavy duty synchronizers. In: 15th international VDI Congress – drivetrain for commercial vehicles 2015, VDI-Berichte 2256, Friedrichshafen, Germany, 16–17 June 2015, pp.597–620. Düsseldorf: VDI-Verlag.

Burton

. Thermal deformation in frictionally heated contact. Wear 1980; 59: 89–96.

Johnsson

. Contact mechanics, Cambridge: Cambridge University Press, 1985.

Back O. Basics of synchronizers. Available at: https://www.hoerbiger.com/upload/file/2013_basicsofsynchronizers.pdf (2013, accessed 17 November 2016).

Hoerbiger. Hoerbiger hs90 sinter-layer. Available at: http://www.hoerbiger.com/upload/file/hoerbiger-hs90-sinter-friction-lining_en.pdf (accessed 16 November 2016).

10.

Palhares FT, Kohtes P and de Aguiar Vendrasco A. FPS – friction pad system. SAE paper 2010-36-0455, 2010.

11.

O’Connor BM, Van Mullekom J, Gahagan M, et al. Influence of additive chemistry on manual transmission synchronizer performance. SAE paper 2002-01-1697, 2002.

12.

Dhanal YV and Jadhav YM. Simulation of clutch inertial effects on gear shifting, synchronizer capacity and accelerated testing of synchronizers. SAE paper 2013-01-2807, 2013.

13.

Diehl. Synchronizer rings – precision parts for the automotive industry. Available at: http://www.diehl.com/fileadmin/diehl-metall/dlc/Diehl_Metall_Schmiedetechnik/Synchronizer_Rings_Brochure_2014.pdf (2014, accessed 16 November 2016).

14.

CEC L-66-99. Evaluation of the synchromesh endurance life using the FZG SSP 180 synchromesh test rig.

15.

Manoz Kumar T, D’mello S and Pattabiraman V. Optimization of synchronizer of a typical 5-speed manual shift synchromesh transmission using statistics-based simulation techniques. SAE paper 2006-32-0069, 2006.

16.

Razzacki ST and Hottenstein JE. Synchronizer design and development for dual clutch transmission DCT). SAE paper 2007-01-0114, 2007.

17.

Zhigang Z, Xiaohui S and Dong G. Dynamic Temperature Rise Mechanism and Some Controlling Factors of Wet Clutch Engagement. Mathematical Problems in Engineering 2016; 12: 1–12.

18.

Nilsson

Isaksson

Prakash

. Effects of area ratio and nature of surfaces on scuffing in lubricated contacts. Proc IMechE, Part J: J Engineering Tribology 2009; 223: 445–455.

19.

Kinugasa

Ishii

Shozaki

et al.

Thermal analysis of the synchronizer friction surface and its application to the synchronizer durability improvement. JSAE Review 1999; 20: 217–222.

20.

Spreckels M. Einfluss der Temperaturverteilung auf das tribologische Verhalten von Synchronisierungen. PhD Thesis, University of Hannover, Germany, 2001.

21.

Neudörfer S. Thermomechanische Einflüsse auf die Tribologie von Synchronisierungen. PhD Thesis, University of Hannover, Germany, 2008.

22.

Häggström D, Stenström W, Sellgren U, et al. A verified and validated model for simulation-driven design of heavy duty truck synchronizers. In: ASME 2015 power transmission and gearing conference, Boston, MA, 2–5 August, paper no. DETC2015-47318.

23.

Häggström

Nyman

Sellgren

et al.

Predicting friction in synchronizer systems. Tribol Int 2016; 97: 89–96.

24.

SK Hydroautomation. Test Rigs. Available at: https:// www.sk-hydroautomation.de/index.php?id=pruefstaende (2007, accessed 9 April 2014).

25.

ISO 25175-2:2012. Geometrical product specifications (GPS) – surface texture: Areal – part 2: Terms, definitions and surface texture parameters.

26.

Schnittger J and Folkesson A. Temperaturförlopp i maskinelement. In: Funktionsanalys och optimering i maskintekniken. Stockholm: Department of Machine Design, KTH Royal Institute of Technology, 1998. pp.65–70.