Transient Frictional Temperature Variations of SSP and DSP Wet Friction Pads by Repeated Engagement Using Slipping Modes

Wet clutch systems are widely used in modern automobile systems including clutch packs in automatic transmissions, other take-off devices in hybrid powertrains, and 4 WD couplings in drivelines. The torque transfer performance of clutch pads is correlated to the friction abruptly decreased by frictional heat; therefore, they need a fast cooling mechanism. The wet, double side plate (DSP) clutch pack is the most common type of wet clutch pack, and its configuration is similar to that of a single side plate (SSP). Regarding the sustainability of clutch pads against thermal load, there is no difference between SSP and DSP clutch packs. However, it is recommended that devices for higher thermal loads be designed in the shape of an SSP clutch pack. We compared and verified thermal load capacities of SSP and DSP clutch packs of same sizes via thermal analysis under repeated loading conditions. Axisymmetric modeling of wet clutch packs is used with velocity—frictional coefficient variations, a repeated engagement process, and lubricant supply rate conditions. Wet clutch packs for high thermal loads are in demand in modern automobile powertrain systems, and the computational results of this work can guide appropriate designs for wet clutch applications under intense thermal operating conditions.