It absolutely was initial introduced in 1939 for vehicles. It is made up of the fluid coupling and 3 planetary gears. They collectively make 3 forward and one reverse pace. There is not any clutch for engagement and disengagement in the motor. Torque converter does exactly the same functionality https://gearbox20752.blogsvirals.com/32943199/how-gearbox-can-save-you-time-stress-and-money