3-2
The main hydraulic circuit consists of suction circuit, delivery circuit, return circuit and drain circuit.
The hydraulic system consists of one main pump, one control valve, one swing motor, four cylinders
and two travel motors.
The swash plate type variable displacement axial piston pump is used as the main pump and is
driven by the engine at ratio 1.0 of engine speed.
1. SUCTION AND DELIVERY CIRCUIT
To cylinders
To motors
To hydraulic oil tank
Hydraulic oil tank
Main control valve
Main pump
GROUP 2 MAIN CIRCUIT
The pumps receive oil from the hydraulic tank through a suction filter. The discharged oil from the
pump flows into the control valve and goes out the tank ports.
The oil discharged from the main pump flows to the actuators through the control valve.
The control valve controls the hydraulic functions.
The return oil from the actuators flows to the hydraulic tank through the control valve and the oil
cooler.
To oil cooler
Suction filter
3-02 (140-7 TIER)