Illustration 1 | g00521135 |
Governor Servo (FUEL ON Direction) (A) Oil inlet (B) Oil outlet (C) Oil passage (D) Oil Passage (E) Engine oil (F) Drain oil (G) FUEL ON direction (1) Valve (2) Piston (3) Cylinder (4) Cylinder sleeve (5) Clevis for fuel injector rack control linkage |
The components of the governor servo are cylinder (3) (part of governor rear housing), cylinder sleeve (4), piston (2), and valve (1). When the governor moves in the FUEL ON direction, valve (1) moves to the left. As valve (1) moves to the left oil outlet (B) opens and oil passage (D) closes. Oil pressure from oil inlet (A) pushes piston (2) and clevis (5) to the left. Oil behind the piston flows through oil passage (C) and around valve (1). The oil then flows into oil outlet (B).
Illustration 2 | g00521182 |
Governor Servo (Balanced Position) (A) Oil inlet (B) Oil outlet (C) Oil passage (D) Oil passage (E) Engine oil (1) Valve (2) Piston (3) Cylinder (4) Cylinder sleeve (5) Clevis for fuel injector rack control linkage |
When the governor spring and flyweight forces are balanced and the engine speed is constant, valve (1) stops moving. Oil pressure from oil inlet (A) pushes piston (2) until oil passage (D) is opened. Oil now flows through oil passage (D) along valve (1), and out through oil outlet (B). With no oil pressure on the piston, piston (2) and clevis (5) stop moving.
Illustration 3 | g00521184 |
Governor Servo (FUEL OFF Direction) (A) Oil inlet (B) Oil outlet (C) Oil passage (D) Oil passage (E) Engine oil (H) FUEL OFF direction (1) Valve (2) Piston (3) Cylinder (4) Cylinder sleeve (5) Clevis for fuel injector rack control linkage |
When the governor moves in the FUEL OFF direction, valve (1) moves to the right. The valve closes oil outlet (B) and opens oil passage (D). Oil under pressure from oil inlet (A) is now on both sides of piston (2). The surface area on the left side of the piston is greater than the surface area on the right side of the piston. Therefore, more force is exerted on the left side of the piston so piston (2) and clevis (5) move to the right.