In the power transmission field, research aims to find a compromise between achieving high engine performance and low fuel consumption. Devices that allow power to be transmitted in rotary motion by varying the relative angular speed between the prime mover and the transferor mostly use constant transmission ratios, such as gearboxes, or continuous transmission ratios based on friction principles, such as belts, or hydraulic fluids. These last include the hydraulic torque converter, which allows power to be transferred from a mover, which may be an internal combustion engine or an electric motor, to a transferor, increasing the torque acting on the latter.