Hydraulic transmission may refer to various transmission methods for transferring engine power to drive wheels, using hydraulic fluid: *

Diesel-hydraulic transmission A diesel locomotive is a type of railway locomotive in which the power source is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the driving whee ...

, used in railway locomotives *

Hydrostatic transmission A continuously variable transmission (CVT) is an automated transmission that can change through a continuous range of gear ratios, typically resulting in better fuel economy in gasoline applications. This contrasts with other transmissions tha ...

, using hydraulic motors to convert the fluid energy into rotary propulsion * , using hydraulic rams acting on a swashplate or crank to convert the fluid pressure into rotation *

Hydrokinetic transmission A torque converter is a device, usually implemented as a type of fluid coupling, that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the ...

, involving one or more torque converters; commonly used in railway locomotives * Hydraulic

automatic transmission An automatic transmission (AT) or automatic gearbox is a multi-speed transmission (mechanics), transmission used in motor vehicles that does not require any input from the driver to change forward gears under normal driving conditions. The 1904 ...

s in automobiles manufactured in the mid-20th century, with trade names such as "Hydromatic"

See also