flyball governor

A flyball governor is a machine component that automatically maintains the rotary speed of an engine or prime mover within set limits, regardless of the load. It works by using centrifugal force.

The governor has a pair of masses, typically balls, that rotate with the engine. Springs or the weight of the balls provide a controlling force. If the engine speed increases, the balls move outward, which in turn adjusts a valve to reduce the fuel or working fluid supplied to the engine, thereby decreasing its speed. Conversely, if the load increases and the speed drops, the balls move inward, opening the valve to supply more fuel and increase the speed. This mechanism is crucial for regulating the performance of various engines and turbines.1