Title: Thermoelastic behaviour of an automatic transmission clutch with a 'finger' piston involving thermoelastic instability

Authors: Przemyslaw Zagrodzki, Wenping Zhao

Addresses: Raytech Composites, Inc., 731 Tech Drive, Crawfordsville, IN 47933, USA. ' Raytech Composites, Inc., 731 Tech Drive, Crawfordsville, IN 47933, USA; Crane Composites Inc., 21125 Protecta Dr., Elkhart, IN 46516, USA

Abstract: An important practical case of frictionally excited Thermoelastic Instability (TEI) in a wet multidisk friction clutch of an automotive transmission with so-called finger piston is investigated. Advanced finite element model of thermoelastic multi-surface contact problem is used. Theoretical results are verified experimentally. The study shows that finger piston used in transmission clutches can trigger unstable thermoelastic behaviour which leads to severe hot spots. In search for solution to this problem two alternative pack designs were investigated: pack with single-sided friction plates and an inverted double-sided pack. Simulations and experiments consistently show that the two alternative designs effectively mitigate hot spots.

Keywords: friction clutch; multidisk clutch; automatic transmission; thermoelastic instability; hot spots; temperature; stress; finite element method; FEM; vehicle design; finger piston.

DOI: 10.1504/IJVD.2008.021154

International Journal of Vehicle Design, 2008 Vol.48 No.1/2, pp.97 - 113

Published online: 06 Nov 2008 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article