Doosan 5001, Инструкция по эксплуатации

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SP000031
Page 9
Swing Motor
Makeup Check Valve
A makeup check valve is installed to compensate for the lack of
supply line oil to prevent cavitation due to the lack of oil being
supplied when the motor turns faster than the expected oil flow
rate to the inlet of the swing motor.
When an excavator suddenly stops swinging, and supply oil
stops flowing to the inlet port of the swing motor, the swing
motor will try to turn a little further due to inertia force. When this
happens, the makeup check valve opens and supplies oil to the
inlet port while the pressure in the inlet port is lower then the oil
waiting in the makeup check valve port.
Operation of Time Delay Valve
Capacity of a driving motor depends on the angle of the swash
plate (16) which is controlled by the tilting valve.
External Pilot Pressure: When Pi = 0 (Large Tilt Angle)
The high-pressure oil acting on the motor comes to act on the
port P of the tilting valve with the high-pressure select function
built in the valve casing. The high-pressure oil flows into the port
Sb as the spool assembled in the tilting switching part sticks to
the plug by spring. This high-pressure oil applies pressure on
the chamber A through the valve casing and the channel A' of
the shaft casing from the port Sb. Oil in the chamber B comes to
flow into the drain line through the channel B °Ê Sa. The tilting
piston moves to the right side by high-pressure oil and the
swash plate moves to and stops at a position where it sticks to
the stopper on the basis of the rotation center, '0'.
Operation of Swing Reactionless Valve
Brake is applied to the lateral port, as the motor receiving pump
action has two ports blocked when a rotating device of hydraulic
motor starts or stops rotating parts by controlling switching
valves. While rotating parts stop operation due to this brake
pressure, 4 or 5 inversions take place. The anti-inversion valve
blocks both ports during ordinary operation but bypasses some
blocked pressure oil to a reverse port for a certain period in case
of inversion to ensure the increase of pressure in the motor and
the decrease of inversion.
FG001324
Figure 5
34, 35
FG001326
Figure 6
FG001327
Figure 7