THEORY OF OPERATION - CONTINUED
HYDRAULIC SYSTEM - CONTINUED
When a constant flow of oil is demanded by steering circuit, supply oil pressure from pump outlet will
increase on right side of flow compensator spool. Pressure on left side of flow compensator spool is sum of
load sensing signal and margin spring pressures. When flow demand is met, flow compensator spool will
meter force on both ends of spool. Once forces become equal on each end of spool, system will stabilize.
Swashplate is held at a relatively constant angle to maintain required flow.
Difference between load sensing signal pressure and supply oil pressure is called margin pressure. Margin
pressure is value of margin spring.
Margin pressure is adjusted by turning adjustment screw on flow compensator spool.