8. TRAVEL FORWARD AND REVERSE OPERATION R/G R/G Ps Ps Pm1 Pm2 Pm2 Pm1 P2 P1 T1,T2 T1,T2 P2 P1 Pn2 Pn1 D B A C DR P Rs CK1 NRV1 Pk BC COMP.
NRV2 B5 S/Motor DB Pc5 Pd5 D5 C5 A5 Pb5 SRG ARG C4 OPTION-B BUCKET CK2 Pa5 (RG) SGo Dr SH PG DR3 Pc4 D4 1 REGENERATIION CUT Pa4 Pb4 B4 Au Dr(R7) Pd4 0 Pc4 0 ARM1 OPTION-A BREAKER Pc4 2 DR2 Pc3 Pa2 1 ARM2 Pd4 Pb3 1 GB GA B(CW) Mu A(CCW) C2 D2 V3 BOOM2 Pb2 1 B2 A2 Pd2 Pc2 SWING BOOM1 P02 DR1 Pa2 Pb2 0 0 Pc1 D1 C1 Patt B1 A1 Pb1 P01 DR0 Pd1 TRAVEL (LEFT) TRAVEL (RIGHT) Pa1 Ptr STRAIGHT TRAVEL T1 P2 P1 Pu MRV SWING ARM BUCKET BOOM TRAVEL (2) (4) (3) (1) (3) (1) (2) (4) Psv A B D E G F H J SH Pd1 Pc1 Pb1 Pa1 (1) (2) (3) (4) a2 a1 A1 A2 a4 Pd2 Pc2 Pc4 0 Pa2 0 Pb2 0 T P Pd4 0 Pa5 Pb5 Dr#,dr#,R# Pm1 (Pump) Pm2 (Pump) Pk (T/Joint) A1 A2 Pi1 (Fl,MCV) Pi2 (Fr,MCV) Pm1 Pm2 A1 A2 ACC P2 P3 P4 PG(S/Motor) Po1(MCV) M a3 T(dr2) T T P1 Dr B1 B3 A3 When the travel levers are pushed forward or reverse position, the travel spools in the main control valve are moved to the forward or reverse travel position by the pilot oil pressure from the remote control valve.
The oil from the both pumps flows into the main control valve and then goes to the both travel motors through the turning joint. The return oil from both travel motors returns to the hydraulic oil tank through the turning joint and the travel spools in the main control valve. When this happens, the machine moves to the forward or reverse. D21073HS16 3-20