Stability of Governors

A governor is said to be stable when for every speed within the working range there is a

 

Definite configuration i.e. there is only one radius of rotation of the governor balls at which the governor is in equilibrium. For a stable governor, if the equilibrium speed increases, the radius of governor balls must also increase.

 

Note : A governor is said to be unstable, if the radius of rotation decreases as the speed increases.