Influence of Paper-Based Friction Material Visco-Elasticity on the Performance of a Wet Clutch

Friction performance of paper-based materials for wet clutches in automotive automatic transmissions is influenced by the entire structure of the material, which is characterized by a combination of porosity and visco-elasticity. In the clutch plate engagement process, the coefficient of friction is higher when the porosity of the material is higher.

In this paper, visco-elasticity of the material was measured by a testing apparatus which was originally designed and built. It has become clear that the compressive visco-elastic deformation increases as the porosity becomes higher.

The relationship between the compressive visco-elastic deformation of the material and the friction torque curve of the clutch plate was also analyzed. It was found that the friction torque curve of a clutch plate is influenced by the visco-elasticity of the material as well as the porosity.