Daewoo Solar 420LC-V, Manual

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S0703010K
Page 3
Accumulator
GENERAL DESCRIPTION
The accumulator is a gas-charged storage
device designed to hold a reserve quantity of
hydraulic fluid under pressure. Accumulators are
used in hydraulic circuits in much the same way
that condensers (or capacitors) are used to
collect, store and maintain electrical charge in a
circuit.
In a hydraulic circuit, minor variations or lags in
pump output that might otherwise cause
unsteady or irregular operation are made up
from the supply of pressurized oil in the
accumulator.
Accumulators are solidly constructed to resist the high operating pressures of the fluids they contain. There
are only three main moving parts: a plug at the top allows pre-charging or expelling gas from the
compressible, pre-charged upper chamber; a valve assembly at the bottom of the accumulator for passing
hydraulic fluid in and out, and an elastic diaphragm to separate the two chambers. The flexible diaphragm
changes shape to conform to the changing pressures and volumes of the two fluids in the upper and lower
chambers.
There are six possible positions the diaphragm
can be in and they are as follows:
1. With no gas charge in the upper chamber
0 bar (0 psi, empty) and no oil in the
bottom 0 bar (0 psi, dry) the elastic
diaphragm hangs loosely.
2. When the pre-pressure charge of gas
(usually nitrogen) is introduced through the
port at the top of the accumulator, the
diaphragm expands to maximum size. The
valve button in the center of the diaphragm
pushes into the fluid opening in the bottom
chamber, sealing off the lower valve. If the
pressure of the gas charge exceeds
system oil pressure, no fluid enters the
accumulator. The button also keeps the
diaphragm from protruding into the lower
valve opening.
Reference
Number
Description
1 Screw Plug
2 Steel Pressure Vessel
3 Diaphragm
4 Fluid Valve
1
2
3
4
ARS1790L
Figure 1
1
2 3
6 5
4
Nitrogen
ARS1800L
Pressure Fluid
Figure 2