PIN AS 1468003 - Caterpillar

Glossary
arcinga discharge of electricity across a gapaccelerationrate at which speed increasesbusan electrical conductorcomparelook at for differencescrankingrotation of the engine by the starter motorcircuitconnected electric componentsdeactivatestop a functiondecelerationrate at which speed decreasesde-energizedpower offenergizedpower onfailsafecircuit that gives protectionhertzcycles per secondhuntspeed changeshydra-mechanicalhydraulically controlled mechanical actioninverselythe opposite of directlyisochronousdesired engine speed does not change because of a change in loadjumperelectrical connectionkilowattmeasure of electric poweroverspeedengine speed higher than rated speedoverridecause normal electrical signals to be cancelednonparallelsingleparalleledelectrically connected together to drive a common loadparallelingall positive poles are connected to one conducter and all negative poles are connected to another conductorproportiona ratioproportionaltwo factors that have a constant ratiopotentiometerelectric component that has variable resistancerampcircuit that controls movement from one level to anotherresponsetime and stability characteristic of a change in output sensing phasingmeasurement and comparison of output with other units in the systemshortany connection between two or more electrical components that is not desiredshieldingsteel braid for protection of a wiresharingtwo or more engines used to drive a common loadspeed droopno load engine rpm minus full load rpmstandbyready for use during an emergencytransferchange from one to anotherWoodward PSG Governors
SCHEMATIC OF LATEST PSG GOVERNOR
1. Return spring. 2. Output shaft. 3. Output shaft lever. 4. Strut assembly. 5. Speeder spring. 6. Power piston. 7. Flyweights. 8. Needle valve. 9. Thrust bearing. 10. Pilot valve compensating land. 11. Buffer piston. 12. Pilot valve. 13. Pilot valve bushing. 14. Control ports. A. Chamber. B. Chamber.Introduction
The Woodward PSG (Pressure compensated Simple Governor) can operate as an isochronous or a speed droop type governor. It uses engine lubrication oil, increased to a pressure of 175 psi (1200 kPa) by a gear type pump inside the governor, to give hydra/mechanical speed control.Pilot Valve Operation
The fuel injection pump camshaft drives a governor drive unit. This unit turns pilot valve bushing (13) clockwise as seen from the drive unit end of the governor. The pilot valve bushing is connected to a spring driven ballhead. Flyweights (7) are fastened to the ballhead by pivot pins. The centrifugal force caused by the rotation of the pilot valve bushing causes the flyweights to pivot out. This action of the flyweights changes the centrifugal force to axial force against speeder spring (5). There is a thrust bearing (9) between the toes of the flyweights and the seat for the speeder spring. Pilot valve (12) is fastened to the seat for the speeder spring. Movement of the pilot valve is controlled by the action of the flyweights against the force of the speeder spring.The engine is at the governed (desired) rpm when the axial force of the flyweights is the same as the force of compression in the speeder spring. The flyweights will be in the position shown. Control ports (14) will be closed by the pilot valve.Fuel Increase
When the force of compression in the speeder spring increases (operator increases desired rpm) or the axial force of the flyweights decreases (load on the engine increases) the pilot valve will move in the direction of the drive unit. This opens control ports