fluid drive

noun Automotive.

1. a power coupling for permitting a smooth start in any gear, consisting of two vaned rotors in a sealed casing filled with oil, such that one rotor, driven by the engine, moves the oil to drive the other rotor, which in turn drives the transmission.

noun

1. a type of coupling for transmitting power from the engine of a motor vehicle to the transmission, using a torque converterAlso called: fluid coupling, fluid clutch, fluid flywheel