Torque Transmission Characteristics of Automatic Transmission Wet Clutches: Experimental Results and Numerical Comparison

Abstract

A test rig has been designed to quantify the torque transmission characteristics of wet clutches. This apparatus is presented and its features discussed. A comparison is made between the torque measurements from the test rig and simulations using a previously developed mathematical model. Results are given for a variety of operating conditions. The data presented here validate the computational model as an accurate tool for wet clutch design and analysis. Important results include accurate torque transfer prediction capabilities, with the limiting factor being precise knowledge of the sliding friction coefficient μc. Another important conclusion of the work is that torque transfer during a single engagement event can be adequately predicted using the isothermal model presented here. The simplicity of the isothermal model, along with its computational efficiency, makes it attractive for wet clutch torque transfer prediction and wet clutch design.