Dynamic load analysis of the lock-up clutch damper spring of automatic transmission

The lock-up clutch of a torque converter is used to enhance the efficiency of the automatic transmission. It is composed of a circumferential friction surface and a torsional damper spring. A damper spring is shocked by the dynamic load transmitted from the engine output shaft and transmission input shaft. The causes of this dynamic load are the engine torque, shifting shock, and impact torque of the driving wheel. Engine shock or shifting shock can be predicted through a performance test. However, the impact of the driving wheel is unpredictable due to the random road conditions. In this study, typical dynamic loading conditions are considered in order to calculate the impact of the damper spring. Quantitative analysis shows that the impact of the driving wheel is 5.8 times that of the engine's exciting torque.