7. COMBINED ARM AND TRAVEL OPERATION ARM CYLINDER BUCKET CYLINDER BOOM CYLINDER SWING MOTOR TRAVEL MOTOR pc1 pa5 (34,2) pa9 pb8 (34,1) P2 pa11 pa8 TURNING JOINT pc7 A7 B7 pc2 pb3 pb7 pa3 pa7 B6 pc6 A6 PT PS P1 P2 PH PA PP PS SH A1 A2 FRONT PUMP REAR PUMP PILOT PUMP HYDRAULIC TANK 900L3HC26 When the arm and travel functions are operated simultaneously, the arm spools and travel spools in the main control valve are moved to the functional position by the pilot oil pressure from the remote control valve and the straight travel spool is pushed to the right by the oil pressure from pilot pump.
The oil from the A1 pump flows into the travel motors through the LH travel spool of the left control valve and the RH travel spool of the right control valve via the straight travel spool. The oil from the A2 pump flows into the arm cylinders through the arm 1 spool and arm 2 spool via the parallel and confluence oil passage. The arm is operated and the machine travels straight. 3-28 ps1 pa11 DR1 pc1 B5 A5 pb9 pb5 pa PO B4 A4 B B1 A A1 DR7 pc7 A3 B3 pb3 ARM1 5 OPTION pb9 ARM2 B8 A8 BUCKET DR2 pc2 p BOOM2 SWING TRAVEL-LH