Accumulators And Gas Bottles
In operation, hydropneumatic accumulators use compressed gas to apply force to hydraulic fluid.
Piston accumulators have a
cylindrical body, sealed by a gas cap
and charging valve at the gas end,
and a hydraulic cap at the fluid end.
A lightweight piston separates the
gas and hydraulic sides. This design
offers high efficiency and flexibility
in most applications due to availability
in a wide range of sizes. Application
advantages include:
- High flow rates.
- Wide temperature range.
- High compression ratios.
- Withstands off-road abuse.
- Almost unlimited size and
mounting possibilities.
- Works well with gas bottles.
Bladder accumulators feature
a nonpleated, flexible rubber bladder
housed within a steel shell. The
open end of the bladder attaches to
the precharging valve at the gas end
of the shell. A poppet valve, normally
held open by spring pressure,
regulates fluid flow through the hydraulic
port. Application advantages
include:
- Suitable for most applications.
- Dirt tolerant.
- Quick response.
- Works well with water and
low-lubricity fluids.
Gas bottles are pressurized metal
cylinders that connect to the gas side
of an accumulator with metal tubing.
Thus, gas bottles can mount some
distance away from the accumulator
and in any orientation offering
flexibility to the machine designer.
They work by increasing the gas
capacity of small accumulators, in
many instances letting the combination
replace larger accumulators.
This tends to reduce costs, save
space and weight, and require lessexpensive
seals. An added advantage
is that gas bottles seldom require
maintenance.