Effects of Groove Orientation on Hydrodynamic Behavior of Wet Clutch Coolant Films

Abstract

A steady-state Reynolds type equation with inertia consideration is solved numerically for a coolant film entrapped between a grooved separator-friction plate pair of a multidisk wet clutch arrangement at a particular instant of the disengaged state. Straight grooves with rounded, trapezoidal, and V-section at different angular orientations are considered and the effects of their geometry and orientation on viscous torque, flow rate, and axial force are presented. Among the profiles studied, the rounded one is found to be better. Grooves inclined with the flow direction cause less viscous torque and, hence, less power loss. The choice of orientation angle, β, to give a maximum outflow or inflow may be helpful for cooling by better convection. For wider radial span and large number of grooves, the minimum operating gap ratio is suggested to be around 2.0. Inertia effects may shift the optimum orientation angle by as much as 10 deg, even at a moderate value of gap Reynolds number.