Abstract
Modern automatic transmission requires high torque capacity, enhanced shift comfort and extended service life within a limited transmission space. Clutches take most of the space in automatic transmission and, therefore, they must be designed very compactly. With required torque capacity for each clutch, selection of proper return and cushion spring types is one of the few alternatives for design engineers for further space savings. The authors investigated various spring types used as clutch return and cushion springs and demonstrated influence of various spring types on transmission length, weight and cost. Simulation and test had conducted to study spring types influence on shift quality. Its effects on transmission efficiency and vibration were also reviewed.