GEAR-SUN 2087635 - Caterpillar

Illustration 1 g00520141
Typical governor (A) Pin (B) Shims (1) Governor drive gear (2) Shaft (3) Flyweight carrier (4) Flyweights (5) Riser (6) Low idle spring (7) High idle spring (8) ShaftThe governor senses engine speed from the camshaft through governor drive gear (1). Shaft (2) connects governor drive gear (1) to flyweight carrier (3). As flyweights (4) rotate, a centrifugal force is created. This force is converted to linear motion, moving riser (5) toward low idle spring (6) and high idle spring (7) when the engine speed increases. At the low idle speed, low idle spring (6) exerts an opposite force on riser (5). At higher engine speeds, high idle spring (7) also becomes compressed. When the engine speed decreases, springs (6) and (7) move riser (5) toward flyweights (4). Thus, there is a unique riser position for every engine speed. Because the riser has a unique position for every engine speed, this is a full range rpm governor. The riser position provides the speed position for the rest of the governor.Note: Pin (A), which is located on riser lever (18) engages in riser (5).
Illustration 2 g00520177
Governor Schematic (A) Pin (C) FUEL ON output to fuel rack (D) FUEL ON input from operator (E) Speed increase input from engine (9) Governor output shaft (10) Limit lever setscrew (11) Control lever (12) Fulcrum lever (13) Pivot lever (14) Limit lever (15) Torque cam lever (16) Torque cam (17) Pivot shaft (18) Riser leverAs riser (5) moves, riser lever (18) causes pivot shaft (17) to rotate. Pivot lever (13) rotates with pivot shaft (17). Thus, pivot lever (13) will also have a unique position for every engine speed.The operator selects the desired engine speed with control lever (11). Control lever (11) and governor output shaft (9) are connected by fulcrum lever (12), which is connected to pivot lever (13). This connection provides the operator with direct communication to the governor output. As the engine speed changes, fulcrum lever (12) moves in order to change the output of the governor to a new stable condition. The same condition occurs when the operator changes the position of control lever (11). This process is shown in the following illustrations.
Illustration 3 g00520296
The engine is operating in a stable condition at low idle. (F) Increase of engine speed (G) More fuel (11) Control lever (12) Fulcrum lever (17) Pivot shaft (18) Riser lever (19) Path of fulcrum pin