TRANSMISSION AR 1148945 - Caterpillar

Illustration 1 g00520706
Governor Linkage And Fuel Ratio Control Schematic (A) Fuel ON output to rack (B) Fuel ON input from operator (1) Governor output shaft (2) Limit flange (3) Inlet port (4) Fuel ratio control (FRC) (5) Output shaft for FRC (6) Screw for FRC (7) Control lever for FRC (8) Control lever (9) Fulcrum lever (10) Pivot lever (11) Pivot shaft (12) Riser lever (13) Torque cam (14) Torque cam screw (15) Torque cam leverThe governor limits the fuel that is injected into the combustion chamber when the rated load or a lug condition is reached. When this condition occurs, limit flange (2) and governor output shaft (1) contact torque cam lever (15). The torque cam lever pivots and torque cam screw (14) contacts torque cam (13). This position is the maximum FUEL ON position. Unlike the other types of governors, there is no pivoting limit lever. However, if more load is applied to the engine in this condition, engine speed will decrease. This decrease will be felt by the flyweights, causing the riser to rotate riser lever (12) and pivot shaft (11) to a new position. Since torque cam (13) is fixed to pivot shaft (11), different torque characteristics can be achieved by changing the profile on torque cam (13) .The fuel ratio control (FRC) limits the fuel by preventing limit flange (2) from moving toward torque cam lever (15). This is accomplished with control lever (7) for the FRC. As boost pressure increases, control lever (7) for the FRC rotates further. This allows the fuel output to increase. At full boost, limit flange (2) will not be restricted by the fuel ratio control.