Komatsu PC500LC-10R Shop Manual page 358

COMPONENT PARTS OF TRAVEL SYSTEM
OPERATION OF SAFETY VALVE OF TRAVEL MOTOR
Both directions (when pressure in chamber (MB) increases during turn to right)
1.
The check valve of the counterbalance valve closes cham-
ber (MB) in the outlet circuit when the machine stops trav-
eling (or travels downhill).
2.
The pressure on the outlet (MB) side increases since the
motor continues rotation because of inertial force.
3.
When this pressure increases above the set pressure, the
force of "Circular area difference between (D1) and (D2) x
Pressure" compresses spring (2).
4.
The pressurized oil moves poppet (1) to the left and flows
into chamber (MA) in the circuit on the opposite side.
Both directions (when pressure in chamber (MA) increases during turn to left)
1.
The check valve of the counterbalance valve closes cham-
ber (MA) in the outlet circuit when the machine stops trav-
eling (or travels downhill).
2.
The pressure on the outlet (MA) side increases since the
motor continues rotation because of inertial force.
10-264
10 STRUCTURE AND FUNCTION
PC500LC-10R
AEP20521
AEP20522
AEP20523