Governors Types, Working, Performance
Flywheel which minimizes fluctuations of speed within the cycle but it cannot
minimize fluctuations due to load variation. This means flywheel does not exercise any control over
the mean speed of the engine. To minimize fluctuations in the mean speed which may occur due to
load variation, the governor is used. The governor has no influence over cyclic speed fluctuations
but it controls the mean speed over a long period during which load on the engine may vary. When
there is a change in load, variation in speed also takes place then-governor operates a regulatory
control and adjusts the fuel supply to maintain the mean speed nearly constant. Therefore, the
governor automatically regulates through linkages, the energy supply to the engine as demanded by
variation of the load so that the engine speed is maintained nearly constant.
Governor is a device which used in an engine to maintain the mean speed of the engine by controlling the
flow of fuel with respect to load on the engine.
It means that, if the load on the engine increases, then it requires more fuel to supply & in another
case when the load on the engine decreases, then it requires less amount of fuel to be supplied.
Function Of Governor:
• The function of the governor is to increase the supply of working fluid going to the prime
mover when the load on the prime-mover increases and to decrease the supply when the load
decreases so as to keep the speed of the prime-mover almost constant at different loads.
• The Governor mechanism is used to regulate the mean speed of an engine, when there are
variations in the load e.g. when the load on an engine increases, its speed decreases,
therefore it becomes necessary to increase the supply of working fluid. On the other hand,
when the load on the engine decreases, its speed increases, and thus less working fluid is
required.
• The governor automatically controls the supply of working fluid to the engine with the
varying load conditions and keeps the mean speed within certain limits.
• Figure shows an illustrative sketch of a governor along with linkages which regulates the
supply to the engine. The governor shaft is rotated by the engine.
• If the load on the engine increases the engine speed tends to reduce, as a result of which
governor balls move inwards. This causes the sleeve to move downwards and this
movement is transmitted to the valve through linkages to increase the opening and, thereby,
to increase the supply.
• On the other hand, a reduction in the load increases engine speed. As a result of which the
governor balls try to fly outwards. This causes an upward movement of the sleeve and it
reduces the supply.
• Thus, the energy input (fuel supply in IC engines, steam in steam turbines, water in
hydraulic turbines) is adjusted to the new load on the engine. Thus the governor senses the
change in speed and then regulates the supply.
• Due to this type of action, it is a simple example of a mechanical feedback control system
which senses the output and regulates input accordingly.
CLASSIFICATION OF GOVERNORS
• The broad classification of the governor can be made depending on their operation.
