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MECHANICAL
GOVERNORS.-A mechanical governor (fig. 9-26, view A) controls the speed of
the engine by virtue of the spring-balanced position of the flyweights.
When the load is decreased or removed from the engine (such as when a
clutch is disengaged) and the speed exceeds its former balanced setting,
the increased speed of the flyweights develops a greater centrifugal
force that upsets the former flyweight spring balance. A new balance is
achieved by the weights as they move outward and further compress the
spring. Any movement of the flyweights is reflected in a vertical change
in position of link A. When the load is increased on the engine, as in
view B of figure 9-26, the fuel that is injected will be inadequate for
the increased load and the engine will slow down. The centrifugal force
of the flyweights will then decrease and permit the former balanced
spring force to move link A down until the new flyweight position again
is balanced by the spring. You should note that the linkage movement
causes an increase in fuel when the load is increased and a decreased
supply of fuel as the load is reduced. From this discussion, it is
evident that the mechanical governor controls the fuel supply by virtue
of the flyweight position |
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