ROD AS 2157457 - Caterpillar

Illustration 10 g01108229
Governor Servo (Balanced Position) (1) Valve (2) Piston (3) Cylinder (4) Cylinder sleeve (5) Fuel rack (A) Oil inlet (C) Oil outlet (D) Oil passage (E) Oil passage (H) Low oil pressureWhen 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 (D) and (E) are opened. Oil now flows through oil passage (E) along valve (1) and out through oil outlet (C). With no oil pressure on the piston, the piston and fuel rack (5) stop moving.
Illustration 11 g01108239
Governor Servo (Fuel off position) (1) Valve (2) Piston (3) Cylinder (4) Cylinder sleeve (5) Fuel rack (A) Oil inlet (C) Oil outlet (D) Oil passage (E) Oil passage (F) Engine oil pressure (I) Fuel off positionWhen the governor moves to the FUEL OFF Position, valve (1) moves to the right. The valve closes oil outlet (C) and opens oil passage (E). Pressure oil from oil inlet (A) is now on both sides of piston (2). The area on the left side of the piston is larger. The area on the right side of the piston is smaller. Similarly, the force of the oil is greater on the left side of the piston. This moves the piston and fuel rack (5) to the right.Dashpot
Illustration 12 g01108251
Dashpot (FUEL ON Position) (1) Check valve (2) Oil reservoir (3) Needle valve (4) Cylinder (5) Piston (6) Dashpot spring (7) Spring seat (A) Oil reservoir (B) Fuel on positionWhen there are sudden vehicle speed and load changes, the dashpot helps the governor with better speed control. The dashpot contains the following components:
Check valve (1)
Needle valve (3)
Cylinder (4)
Piston (5)
Dashpot spring (6)
Spring seat (7) When the governor moves toward the FUEL ON position, spring seat (7) and piston (5) move to the right. This movement pulls oil from oil reservoir (2) through check valve (1) and into cylinder (4).
Illustration 13 g01108273
Dashpot ( FUEL-OFF Position) (1) Check valve (2) Oil reservoir (3) Needle valve (4) Cylinder (5) Piston (6) Dashpot spring (7) Spring seat (A) Oil reservoir (C) Fuel off position (D) Low oil pressureWhen the governor is moved to the Fuel-Off position, the spring seat (7), and piston (5) are moved to the left. This movement pushes oil out of cylinder (4), through needle valve (3), and into oil reservoir (2) .If the governor movement is slow, the oil provides no restriction to the movement of the piston and spring seat. When the governor is moved quickly to the FUEL-OFF position, the needle valve gives a restriction to the oil. The piston and the spring seat will move slowly. Fuel Ratio Control
Illustration 14 g01108286
Fuel Ratio Control (1) Inlet air chamber (2) Diaphragm