Fluid Coupling is a mechanism which helps in transferring the rotational force from one axis to another axis. The axis can be termed as transmitted and receiving axis. The transfer is done with the help of an accelerated or decelerated fluid (oil). The acceleration of load to the maximum and the starting of the motor nearly free of load are done by the fluid coupling.
The machines that use fluid couplings consist of two rotating surfaces known as impeller and runner. The fluid is used to control the speed. Both impeller and runner contain the fluid. The fluid flow with high velocity and impinges the runner blades which in turn powers up impeller and runner bladed rotors. This transfers the energy from the high velocity fluid to the runner and the fluid leave at the low velocity.
The applications of this can be seen in:
- Industrial or Marine machine drives
- Variable speed operation in the power transmission systems
- Conveying systems
- Processing drives