The Effect of Separator Flatness on the Performance and Durability of Wet Friction Clutches

The automatic transmission clutch represents a complex system involving critical interactions between the separator plates, fluid, operating conditions and friction material. This paper focuses on the effect of separator plate flatness on the performance and durability of two friction materials on an SAE #2 machine.

The data from this study shows that flat separator plates yield higher dynamic coefficients and lower wear when compared to non-flat plates. These effects were obtained for separator plates with peak-to-peak departure from flatness values between approximately .08mm and .25mm.

In addition, other variables such as material elastic modulus, separator plate thickness, and material operating pressure were studied. The use of soft friction materials to improve performance with non-flat reaction plates was quantified.