HYDRAULIC, PNEUMATIC, ELECTRICAL, ELECTRONIC SYSTEMS - PRIMARY HYDRAULIC POWER SYSTEM
Limiting Maximum System Pressure To limit the maximum output pressure of the piston pump under normal operating conditions, a pressure compensating valve, located adjacent to the flow compensator valve, is incorporated in the swash plate control circuit. This valve limits the pressure to 190 bar (2755 psi) and operates as follows: As the pressure in gallery D increases to 205 bar (2973 psi) the pressure compensator valve spool moves against the valve return spring and opens gallery D to gallery C. The pressure in gallery D is now applied to the servo piston which changes the swash plate angle to reduce pump output to minimum flow. This operating mode is referred to as high pressure standby. If the pressure in gallery D for some reason exceeds the setting of the pressure compensating valve there is a system safety valve set to 245 bar (3553 psi) to prevent consequential damage that may occur due to excessive pressures. The Low-Pressure Priority Valve will continue to sense the changes in system pressure to regulate the low-pressure system to 17 bar (247 psi). 1 3 5 7 9
Electro Hydraulic Remote (EHR) Valve Load Sensing Line from EHR Valve Load Sensing Line from EDC Valve Load Sensing Line from Trailer Brake Valve Flow Compensating Valve 22 bar (319 psi)
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Variable Displacement Pump Assembly Steering System Supply oil Charge Pressure Bypass Valve 3 bar (44 psi) Main Intake Filter Vacuum Switch Low Temperature Switch 40 °C (104 °F) Charge Pressure Filter
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Main System Relief Valve 245 bar (3553 psi) Low Pressure Regulating Valve Trailer Brake Valve End Plate with Pressure Regulator Valve for Supply to EHR Pilot Line 20 - 22 bar (290 319 psi) Low pressure Supply to Transmission clutches, Four Wheel Drive, Differential Locks, PTO clutch and PTO Brake
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Low Pressure Pilot Line for EHR Control Spool Electronic Draft Control (EDC) Valve Lift Ram Load Sensing Shuttle Valves Pressure Compensating Valve 205 bar (2973 psi) Low Charge Pressure Warning Switch Steering Pump Supplementary lube valve 0.8 bar (12 psi) Main Intake Filter Charge Pump Charge Pressure Filter Dump Valve 6 bar (87 psi) Trailer Brake Valve Outlet Low Pressure Relief Valve 30 bar (435 psi) Low Pressure Regulating Valve Assembly High Pressure Supply to Front Suspension or Mid Mount Remotes, where fitted
System Pressure 205 bar (2973 psi)
Return To Reservoir
Standby Pressure 22 bar (319 psi)
Steering Circuit
Control Pressure
Low Pressure 17 bar (247 psi)
Charge Pressure 3 bar (44 psi)
Trapped Oil
Suction
Lubrication Oil
MAXXUM-T3-DRAFT 02/11/2011
A.10.A / 76