InsaneHydraulics - Sergiy Sydorenko © 2009-2011 All Ridghts Reserved
About a month ago a reader from the US sent me an email that made my
jaw drop - in his letter John described an emergency repair performed on
the main pump of his Koehring 6611 excavator,
and now I am officially declaring that this overhaul is, by far, the
baldest and most insane pump repair I've ever seen or heard of in my
entire career!
One of the pistons of the main double pump lost a slipper,
and since an overhaul estimate was fourteen grand in parts alone, the
quick, cheap and, I must say, most ingenious solution was - to open a
thread in the damaged barrel bore and plug it with a threaded piece of
rod!
And it worked! Like a charm it did! Obviously the flow
pulsation during high regimes was present, so after 30 hours of
operation a bladder accumulator
was installed in the P line, which took care of 90 percent of the noise
and vibration. Last time I heard from the man the excavator had done
eight more hours of service since the accumulator introduction. I don't
know if the machine is still working, but I do hope the man contacts me
if his unconventional creation fails!
I was honest with John when I told him that, although I
found the idea of solving a damaged bore problem by plugging it a
brilliant avant-garde invention I would never think of, the unit
wouldn't last long, because when an axial piston pump wears down to the
point where piston shoes start slipping off of the pistons - there isn't
much you can do to make it last longer without replacing old parts with
new ones. It's amazing that the pump didn't disintegrate when the
slipper came off in the first place (apparently the machine was stopped
just in time)!
In any case - everybody should know that it is possible
to make an axial piston pump work with one of the barrel bores plugged -
and for this radical discovery alone the man deserves praise and
standing ovation! Unfortunately there are no pictures of the plugged
bore, so these few pics John took to identify the parts are the only
images there are.
To all regular IH readers - take this knowledge, and use it wisely... To John - I truly wish your pump last for at least ten thousand hours!!!
