Are you curious to know about fluid coupling? You want to understand its details and designing. Then this discussion is certainly for you. This hydrodynamic device is used for transmitting rotating mechanical power. Automobile transmissions use it as a mechanical clutch alternative. It finds its application in industrial machine and marine drives where there is variable operation of speed. It is also used in situations where the start-up is controlled without power transmission system’s shock loading.
The fluid coupling contains three components besides hydraulic fluid. Firstly, there is housing which is also called the shell. It contains the turbines and fluid. Then you will find two turbines that are components similar to fan. One of them is connected to input shaft and is called impellor, input turbine or primary wheel. The other is connected to output shaft, and is known as output turbine, runner or secondary wheel.
There is a prime mover that is typically an electric motor or internal combustion engine. It rotates the driving turbine. The motion of the impellor imparts both rotational and outwards linear motion to fluid.
The pump directs hydraulic fluid. Due to its shape the flow is in direction of output turbine. Any angular velocities difference of input and output stage causes net force on output turbine. This results in a torque. Due to this, it rotates in the direction of the pump.
The fluid motion is toroidal in nature that travels in only one direction. If difference in angular velocities at input and output is present then there is circular component in motion. If input as well as output stages possess same angular velocities then net centripetal force is not there. The fluid motion is co-axial and circular with the rotation axis. As a result, the fluid flow from first turbine to the second is absent.
