Hydraulic Schematic - Doosan Power Train D50S-5 Specifications Systems Operation Testing & Adjusting Disassembly & Assembly

Hydraulic Schematic

(1) RELIEF VALVE. (2) INCHING VALVE. (3) ACCUMULATOR VALVE. (4) SOLENOID VALVE.
(1) RELIEF VALVE
◆ FUNCTION
To maintain constant pressure in the CONTROL
VALVE, preventing excessive rise or fall of
pressure, and supply oil to TORQUE
CONVERTER.
Power Train
◆ OPERATION
The oil from the PUMP is fed to VALVE via "A."
As pressure rises, the oil through "A" overcomes
the spring force and pushes SPOOL to left.
When the SPOOL is pushed to left by oil
pressure, "A" and "B" are connected and the oil
from "A" enters TORQUE CONVERTER through
"B" and pressure falls.
When the pressure fell, PISTON returns reducing
the inflow to the TORQUE CONVERTER, raising
pressure again. The minimum pressure is
maintained by the repeated operation of the
SPOOL.
In the event that the pressure is keep rising when
oil flows to TORQUE CONVERTER, SPOOL is
pushed to right, and at the preset pressure, the
oil entered through "A" is drained through "C"
preventing the pressure rise higher than the
preset value.
18 System Operation