Power take-off: Difference between revisions

A '''power take-off''' (PTO) is a spinning shaft, usually on a [[tractor]] or [[truck]] that can be used to provide power to an attachment or separate machine. It is designed to be easily connected and disconnected.

The PTO and its associated shafts and [[universal joint|U-joints]]s are a common cause of trauma in farming and industry. When a piece of clothing, which can be as small as a single thread, touches a spinning part it can be pulled around the part. The clothing and the person wearing it are instantaneously pulled into the shaft resulting in loss of a limb or death. Some implements do use metal guards to try to keep a person from becoming entangled in a PTO shaft, but even with guards people need to exercise caution around PTO shafts when they are plugged into a tractor.

Agricultural PTOs are [[standardisation|standardized]] in dimensions and speed. The original specification calls for operation at 540 rpm. Two newer specifications, supporting higher power applications, operate at 1000 rpm[[Rpm]] and differ in shaft size. The larger shaft has 21 splines, while the smaller has 20. All three types rotate clockwise when viewed from the implement.