Accumulators (Hydraulic & Pneumatic)

Hydraulic accumulator is an accessory of a hydraulic system.
A hydraulic accumulator is a pressure storage reservoir in which a non-compressible hydraulic fluid is held under pressure by an external source.
The external source can be a spring, a raised weight, or a compressed gas. An accumulator enables a hydraulic system to cope with extremes of demand using a less powerful pump, to respond more quickly to a temporary demand, and to smooth out pulsations. It is a type of energy storage device.

1. ACCUMULATORS
1Maintainer
Mohammad Azam Khan
M. Tech.
Industrial & Production

2. ACCUMULATOR
2Maintainer Mohammad Azam Khan
•Hydraulic accumulator is an accessory of a hydraulic system.
•Ahydraulicaccumulatorisapressurestoragereservoirinwhicha
non-compressiblehydraulicfluidisheldunderpressurebyan
externalsource.
•The external source can be a spring, a raised weight, or a compressed
gas. An accumulator enables a hydraulic system to cope with
extremes of demand using a less powerful pump, to respond more
quickly to a temporary demand, and to smooth out pulsations. It is a
type of energy storage device.

3. TYPES OF HYDRAULIC
ACCUMULATOR
3Maintainer Mohammad Azam Khan
•The function of hydraulic accumulator is to store pressurizedoil.
•Types:
–Weighted accumulator
–Spring loadedaccumulator
–Gas-charged accumulator

4. WEIGHT LOADED
ACCUMULATOR
4Maintainer Mohammad Azam Khan
•This is the oldest type of accumulator. This consist of a vertical,
heavy steel cylinder which incorporates a piston with packing to
prevent leakage.
•A dead weight is attached to the top of the piston.
•The force of gravity of the dead weight provides the potential energy
in the accumulator.
•The main disadvantages of this of accumulator is its large size
and heavy weight makes it unsuitable for mobile equipment.

5. WEIGHT LOADED
ACCUMULATOR
5Maintainer Mohammad Azam Khan
Theweight-loadedtype is historically the oldest type ofaccumulator.
It consists of a vertical heavy wall steel cylinder, which incorporates a
piston with packing to prevent leakage (Figure 7.14). A deadweightis
attached to the top of the piston.

6. SPRING LOADED
ACCUMULATOR
6
•A spring loaded accumulator is
similar to the weight loaded
type, except that the piston is
preloaded with a spring.
Maintainer Mohammad Azam Khan

7. TYPES
7
•The three types of gas-charged accumulators are bladder, piston and
diaphragm.
Maintainer Mohammad Azam Khan

8. DIAPRAGMTYPE
8Maintainer Mohammad Azam Khan

9. BLADDERTYPE
9Maintainer Mohammad Azam Khan
•Themostpopularoftheseis
thebladdertype.Bladder
accumulatorsfeaturefast
response(lessthan25
milliseconds),amaximumgas
compressionratioofaround
4:1andamaximumflowrate
of15liters(4gallons)per
second.

10. ACCUMULATOR
10Maintainer Mohammad Azam Khan