Papar XI (iii) Finite Element Simulation of the Interfacial Contact Behaviour of an Automotive Gearbox Synchroniser

The contact pressure distribution at the cone clutch operating interface of a transmission synchroniser may have a significant effect upon gear shift quality and reliability. Modifications have been made to a standard finite element package to facilitate accurate predictions of such contact pressure distributions. Results illustrating the effect of varying shift lever load;, material properties and cup/cone differential angle are presented for the particular case of a commercial vehicle pin-type synchroniser. Tests have been carried out on production components over a large number of operating cycles to accurately measure wear signatures which, using pin-on-disc wear data, are then converted to pressure distributions. Good agreement between numerical and experimentally-derived interfacial pressures is obtained for certain assumed values of friction material modulus. Additional assumptions in the finite element approach and implications of the results for synchroniser design are discussed.