INFLUENCE OF SPATIAL HEAT FLUX DISTRIBUTION ON TEMPERATURE FIELD IN A DRY CLUTCH DURING A LAUNCH MANOEUVRE

The tribological contact under sliding condition in clutch facing surfaces during engagement manoeuvres is strongly affected by heat transfer occurring in the system. The frictional forces acting on contact surfaces produce mechanical energy losses which are converted in heat with ensuing temperature increase. In this paper, in order to estimate the error due by neglecting the effective spatial distribution of heat flux the Authors explored the thermal generation in a dry clutch architecture during a vehicle launch manoeuvre. The results of the longitudinal vehicle dynamics have been used in a FEA to evaluate how the spatial distribution of heat flux influences the temperature field of contact surfaces. To this aim, simulations obtained by considering the same engagement manoeuvre but under different hypothesis, i.e. linearly dependable with disc radius and uniform heat flux have been compared. The results showed that the estimated thermal field in dry clutch components changes by varying hypothesis. In particular, in the first case the interface temperature is higher than the second one and the difference could grow with repeated engagements leading to underestimate the thermal stress of clutch components. In such a way, this paper aims at providing useful references to design and control engineers in order to improve the dry-clutch transmissions performances