FUEL SYSTEM
SYSTEMS OPERATION
TM 5-3805-263-14&P-2
changes. The dashpot has cylinder (1), piston (2).
dashpot spring (3), needle valve (5) and check valve
(6). Piston (2) and spring seat (4) are fastened to
dashpot spring (3).
When the governor spring and flyweight forces are
balanced and the engine speed is constant, valve (1)
stops moving. Pressure oil from oil inlet (A) pushes
piston (2) until oil passages (C and D) are opened.
Oil now flows through oil passage (D) along valve (1)
and out through oil outlet (B). With no oil pressure
on the piston. the piston and fuel rack (5) stop
moving.
When the governor moves in the FUEL OFF dir-
ection, valve (1) moves to the right. The valve closes
oil outlet (B) and opens oil passage (D). Pressure oil
from oil inlet (A) is now on both sides of piston (2).
The area of the piston is greater on the left side than
on the right side of the piston. The force of the oil is
also greater on the left side of the piston and moves
the piston and fuel rack (5) to the right.
Dashpot
The dashpot helps give the governor better speed
control when there are sudden speed and load
When the governor moves toward FUEL ON,
spring seat (4) and piston (2) move to the right. This
movement pulls oil from oil reservoir (7) through
check valve (6) and into cylinder (1).
When the governor moves toward FUEL OFF,
spring seat (4) and piston (2) move to the left. This
movement pushes oil out of cylinder (1). through
needle valve (5) and into oil reservoir (7).
If the governor movement is slow. the oil gives no
restriction to the movement of the piston and spring
seat. If the governor movement is fast in the FUEL
OFF direction, the needle valve gives a restriction to
the oil and the piston and spring seat will move
slowly.
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