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DISTRIBUTION SYSTEMS - PRIMAR Y HYDRAULIC POWER SYSTEM
delivery When this pressure reaches - bar ( 340 - 390 psi ) the pump enters its low pressure standby This occurs almost instantly and makes engine starting easier
Pressure / flow delivery and compensation
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When oil required the flow controlled the dif ference pressure opposite ends the compensator
When a control valve pressure the outlet the piston pump drops slightly Spring and signal line pressure shift the flow compensator spool away from the spring allowing oil from the control piston drain past the spool and the oil drains out the control piston, the swash plate angle increases and pump flow rises until the flow demand has been The flow from the pump determined the size the orifice the control valve which being This orifice created limiting the main valve spool travel within the control
When a control valve oil pressure the circuit being supplied increases its operating This pressure transmitted through the sensing line the spring end the compensator
Increased flow demand
When additional control valve pressure drops slightly the pump pressure The sator spool moved and allows the oil behind the control piston drain The swash plate moves and pump flow increases until the extra demand for flow has been
Pressure the pump outlet increases until - bar ( 340 - 390 psi ) above the signal line This pressure increase moves the pump compensator spool against the allowing suf ficient flow past the spool the control piston. This action the piston moves the swash plate a position where increased flow maintained and the pressure
Decreased flow demand
When flow demand pump pressure increases until the pump outlet pressure exceeds the signal line sure more than 23.527.0 bar ( 340 - 390 psi ) The flow compensator spool moves down allow some oil flow into the pump control This action the piston destrokes the pump against the spring and reduces pump flow
When pump flow falls match the reduced the dif ference pressure sensed the opposite sides the compensator spool returns 23.527.0 bar ( 340 - 390 psi ) . The compensator spool moves and blocks f the passage the control which locks the swash plate that pumping
High pressure standby
The hydraulic system protected limiting its maximum pressure 202 - 203 bar ( 2930 - 2950 psi ) through a signal relief This protection for when a hydraulic cylinder reaches the end its stroke when unconnected remote valve
NOTE: Hitch system pressure not limited a signal relief Hitch system maximum pressure limit 224 bar ( 3250 psi )
When system pressure reaches the setting the high pressure compensator the pump high pressure pensator spool shifts against its allowing the full pump pressure applied the pump control This destrokes the pump very rapidly from full stroke almost zero (within 8 The swash plate lizes provide just suf ficient flow make for internal
The pump remains the high pressure standby mode until the valve operation returns neutral. When this occurs, signal line feed from the valve cut Signal pressure drops because the drain orifice plug passage open the pump case When there signal line the pump immediately returns a low pressure standby
