HYDRAULIC, PNEUMATIC, ELECTRICAL, ELECTRONIC SYSTEMS - PRIMARY HYDRAULIC POWER SYSTEM
Generating Low Pressure Standby Low pressure standby is the system pressure 21 bar (305 psi), maintained by the hydraulic pump when high pressure hydraulic circuits are not being operated. Control of the swash plate, which regulates the output of the variable displacement piston pump, is achieved by the flow and pressure compensating valves located on the top of the pump. When the engine is first started, the swash plate return spring positions the swash plate for maximum output of the pump. During engine start up, Low Standby Pressure has not yet been generated by the pump and the flow compensating valve spool is held to the right by spring pressure. The position of the spool prevents oil pressure generated by the pump, being applied through gallery D to the swash plate servo piston through gallery "C". The swash plate consequently remains in the maximum flow position until the piston pump has developed standby pressure. 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)
2 4 6 8 10
11 13 15 17 19 21
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
12 14 16 18 20 22
23 25 27 29
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
24 26 28 30
31
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 / 68