Exam Question

### (a) Operation of a Mechanical-Hydraulic Main Engine Governor
A mechanical-hydraulic governor is a speed-sensing and actuating device that automatically controls the engine's fuel supply to maintain a set speed under varying load conditions. Its operation is based on balancing the centrifugal force of rotating flyweights against the force of a pre-compressed speeder spring.
#### Principle of Operation
The core principle involves a direct relationship between engine speed and the position of rotating flyweights. The centrifugal force generated by these flyweights is proportional to the square of the rotational speed ($$ F_c \propto \omega^2 $$). This force is used to control a hydraulic pilot valve, which in turn directs high-pressure oil to a power piston (servo motor). The power piston provides the significant force required to move the engine's fuel pump racks.