Optimum Design of Front Cover Taper Angle in Torque Converter by Finite Element Method

Since torque converter slip in the coupling range has long been recognized as a source of power loss, numerous lock-up clutch system of torque converter has been investigated. The lock-up clutch in the torque converter improves fuel economy by eliminating torque converter slip at high speed range. Besides, lock-up function at low speed is necessary for better fuel economy. But, when the lock-up is engaged at low speed, NVH problem takes place due to shudder, friction characteristics, and so on. In addition, for more frequent lock-up operations, we need more durable torque converter lock-up clutch system. Front cover taper angle in the torque converter, friction material, contact surface roughness, and damper characteristics are important design parameters for improving NVH and drivability. Particularly, front cover taper angle in the torque converter should be determined on the basis of the surface pressure between front cover and friction Material. In this study the pressure distribution of the contact surface is investigated by finite element method. Moreover, we propose design optimization method for torque converter taper angle.