It had been initial introduced in 1939 for vehicles. It consists of the fluid coupling and three planetary gears. They collectively make 3 forward and a person reverse velocity. There's no clutch for engagement and disengagement with the engine. Torque converter does precisely the same perform which the clutch https://gearbox70233.full-design.com/the-smart-trick-of-gearbox-that-no-one-is-discussing-76202353