The
following is an interesting article about a problem that has a great
potential for damaging equipment that utilizes dual hydraulic cylinders
that must act together.
Problem:
A dump truck owner noticed that his truck bed wasn't raising evenly.
One cylinder was not extending as far as the other, placing a lopsided
load on the truck. He inspected the cylinders and other components
for leaks and damage, but no problems were found. Because the lopsided
bed was becoming a safety hazard, the owner removed it from the
service and replaced the cylinder that was not fully extending.
Over time, though, the problem, reoccurred.
Solution:
Add check valves to the flow divider circuit.
Flow dividers donít operate at 100 percent efficiency, regardless
of manufacturer. In this application, the divider was operating
at 98% efficiency. This meant that only one cylinder was extending
fully. The other was extending to 98 percent of its total stroke,
an acceptable amount in most applications. But because the cylinder
strokes were never equalized, the second cylinder extended less
and less with each subsequent actuation.
The system needed a way to equalize the cylinder strokes after each
actuation. The Gresen distributor recommended installing check valves
in the cylinder return lines. This allowed the cylinders to bottom
out on the return stroke, equalizing the system and curing the problem.
We can
order and install the proper parts for your equipment that will
prevent potential damage.
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