|
Sr. No. |
Hydropneumatic |
Hydraulic |
Pneumatic |
|
1 |
Resistant
to fluctuating load |
Resistant
to fluctuating load |
Not
resistant to fluctuating load |
|
2 |
High
speed possible |
Speed is
always limited |
Very high
speed possible |
|
3 |
Suitable
for feed movement in machine tool application |
Very
Suitable for feed movement of machine tools |
Unsuitable for feed movement |
|
4 |
Suitable
for low operating pressure may generate medium pressure with
hydropneumatic booster system |
Operating
pressure may be from low to very high |
Operating
pressure is generally 6 bar (g)
|
|
5 |
Uses air
as operating fluid with oil as check medium |
Uses only
oil |
Uses only
air |
|
6 |
Occasional change in oil may be necessary |
Oil is
changed as per schedule |
Does not
arise |
|
7 |
No
hydraulic pump is necessary, small oil reservoir is
sufficient |
Pump is
necessary |
Does not
arise
|
|
8 |
Air
supply is needed |
Does not
arise |
Air
supply is necessary |
|
9 |
System
rigidity is good |
System
rigidity is good |
Rigidity
is poor |
|
10 |
Very low
operating cost |
Moderate
operating cost |
Very low
operating cost |
|
11 |
Control
of cylinder stroke easily attainable and precise |
Very
precise stroke control attainable |
Stroke
control is easy but fluctuation unavoidable |
|
12 |
Simple
maintenance |
Simple
maintenance |
Simple
maintenance |
|
13 |
No
cavitation problem except possibility of air and oil mixing
sometimes |
Cavitation is a big problem to be tackled appropriately |
No such
problem |
|
14 |
Overall
cost is low to moderate |
Overall
cost is moderate to high |
Overall
cost is low |
|
15 |
Weight to
pressure ratio is large |
Weight to
pressure ratio is very small |
Weight to
pressure ratio is large |
|
16 |
Cylinder
cushioning is required |
Cylinder
cushioning may or may not be needed |
Cylinder
cushioning is not needed |
