A fluid coupling is used to transmit rotating mechanical power, providing variable speed and controlled soft start-up in machine drives, avoiding shock loading. This makes fluid couplings an ideal alternative to mechanical clutches, as well as for applications such as conveyors and industrial machine drives.
A fluid coupling or hydraulic coupling is a hydrodynamic or 'hydrokinetic' device used to transmit rotating mechanical power. It has been used in automobiletransmissions as an alternative to a mechanical clutch. It also has widespread application in marine and industrial machine drives, where variable speed operation and controlled start-up without shock loading of the power transmission system is essential.
Hydrokinetic drives, such as this, should be distinguished from hydrostatic drives, such as hydraulic pump and motor combinations.