transmission fluid coupling process

What is the process fluid coupling drive it? Here, I will briefly explain.
Fluid coupling transmission efficiency is equal to the output shaft speed ratio of the input shaft speed. General Hydraulic hose fittings coupling normal operating conditions when the speed ratio above 0.95 can obtain higher efficiency. Hydraulic coupling due to the characteristics of the working chamber and the pump wheel, turbine shapes differ. It generally rely on natural body heat, does not require external cooling supply. Transmission fluid coupling process can be seen as the process together.