TRAVEL CIRCUIT OPERATION OVERLOAD RELIEF VALVE TRAVEL MOTOR DEVICE RH LH Dr Ps Ps Dr MB REG MA MB REG MA VA(FW) VB(BW) VB(FW) VA(BW) COUNTER BALANCE VALVE C A D B Dr P Pk TO/FROM MAIN CONTROL VALVE 260L3HC16A Valves are provided on travel motors to offer the following functions. 1) COUNTER BALANCE VALVE When stopping the motor of slope descending, this valve to prevent the motor over run. 2) OVERLOAD RELIEF VALVE Relief valve limit the circuit pressure below 350 kgf/cm 2 (4980 psi ) to prevent high pressure generated at a time of stopping the machine. Stopping the motor, this valve sucks the oil from lower pressure passage for preventing the negative pressure and the cavitation of the motor.
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