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How did James Watt's flying-ball governor regulate steam-engine speed?
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Six simple machines for transforming energy into work.
James Watt’s flying-ball governor regulated the speed of a steam engine by utilizing centrifugal force as a form of negative feedback control.1
The device consisted of weighted balls attached to a vertical spindle by hinged arms, which were mechanically coupled to the engine's output shaft. The mechanism functioned as follows:1
- Speed Increase: As the engine's rotational speed increased, centrifugal force caused the weighted balls to move outward.21
- Valve Regulation: This outward motion was transmitted to a valve that reduced the supply of steam being fed to the engine.21
- Speed Reduction: By restricting the steam flow, the engine's speed was effectively lowered, maintaining a constant operating level.21
Conversely, if the engine's load increased and its speed dropped, the balls would move inward, allowing more steam to enter and increasing the engine's power. This elegant design eliminated the need for manual human intervention to regulate engine speed.21