Hydraulic system 5.7
Dipper arm check valve (load retaining valve) • Rod side dipper arm cylinder A pilot-operated load retaining valve is used to prevent spool leakage, which allows the cylinder to retain its home position. Retracting the dipper arm The oil opens the check valve and flows to the rod side of the dipper arm cylinder. Extending the dipper arm The load on the check valve is reduced by means of the pilot control line and a piston (return to tank). This allows the base side oil to flow back via the check valve.
dr1
Rod side dipper arm
pc1
Line Dipper arm 2
A5 B5 pb5
Joystick control
pb9 pa5
P1
T1
pa9
5-18
918170/AP0905
