Friction Material for Continuous Slip Torque Converter Applications: Anti-Shudder Considerations

The basic friction material design considerations for continuous slip torque converter clutches are discussed. A bench test method was developed to predict the performance of continuous slip clutches at different temperatures, pressures, and velocities. A test machine which can analyze a full-sized friction plate was also designed.

Two types of shudder exist in continuous slip clutches: “initial shudder” and “long-term shudder”. These shudder phenomena were investigated. The results indicated that the following factors influence the initial shudder: adsorption capability, elasticity, and “damping” properties of the friction materials, as well as the oil temperature and the slipping velocity. The long term durability and shudder resistance were found to be affected by the heat transfer capability and the surface treatment of friction material.