Was (wer) ist power off - definition
![A PTO (in the box at the bottom) in between the [[three-point hitch]] of a tractor.](https://commons.wikimedia.org/wiki/Special:FilePath/A Tractor's rear.jpg?width=200 "A PTO (in the box at the bottom) in between the [[three-point hitch]] of a tractor.")
![Yellow shaft provides PTO drive to a [[flail mower]] on this [[International Harvester]] tractor](https://commons.wikimedia.org/wiki/Special:FilePath/International Harvester Cub Tractor (1963).jpg?width=200 "Yellow shaft provides PTO drive to a [[flail mower]] on this [[International Harvester]] tractor")
![Rear crossbar with PTO hydraulic connectors and coupling on a [[Unimog]] 421](https://commons.wikimedia.org/wiki/Special:FilePath/Unimog-1980-05.jpg?width=200 "Rear crossbar with PTO hydraulic connectors and coupling on a [[Unimog]] 421")
![Shutdown options have been moved from a separate dialog box to the [[start menu]], in [[Windows Vista]] and later versions of Microsoft Windows. The above is from [[Windows 7]].](https://commons.wikimedia.org/wiki/Special:FilePath/Shutdown Options 7.png?width=200 "Shutdown options have been moved from a separate dialog box to the [[start menu]], in [[Windows Vista]] and later versions of Microsoft Windows. The above is from [[Windows 7]].")
![[[Windows 10]] power menu, opened from the [[Start Menu]]](https://commons.wikimedia.org/wiki/Special:FilePath/Windows 10 power menu.png?width=200 "[[Windows 10]] power menu, opened from the [[Start Menu]]")
![[[Windows XP]] shutdown dialog box](https://commons.wikimedia.org/wiki/Special:FilePath/Windows XP Shutdown.png?width=200 "[[Windows XP]] shutdown dialog box")
Wikipedia
A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine.
Most commonly, it is a splined drive shaft installed on a tractor or truck allowing implements with mating fittings to be powered directly by the engine.
Semi-permanently mounted power take-offs can also be found on industrial and marine engines. These applications typically use a drive shaft and bolted joint to transmit power to a secondary implement or accessory. In the case of a marine application, such shafts may be used to power fire pumps.
In aircraft applications, such an accessory drive may be used in conjunction with a constant speed drive. Jet aircraft have four types of PTO units: internal gearbox, external gearbox, radial drive shaft, and bleed air, which are used to power engine accessories. In some cases, aircraft power take-off systems also provide for putting power into the engine during engine start. See also Coffman starter.
Also, in wave energy technology to harness the ocean wave energy, the power take-off systems are used. The working principle can vary and be classified as a direct mechanical drive system, hydro turbine transfer system, hydro motor system, pneumatic air turbine transfer system, and direct electrical drive system.
