I would like to use a small hydraulic pump [ John S. Barnes , model #
5490] as a motor to drive a water pump. This appears to be a simple
pump, no piston, and I was wondering if there is any check valve
inside and if I need to be concerned about rotation?
I assume this is a gear pump? If so, it should work as a
motor with pressure applied to what was the output port; in
other words you're reversing the flow thru the pump,
turning it into a motor.
Whether it will tolerate being reversed by pressurizing the
other port depends on the actual construction of the pump.
The usual problem with this arrangement is that the shaft
seal may be subjected to high pressure, and it may not be
up to the job. I'm not real familiar with the construction
of gear pumps, so that may or may not be an issue. (Or this
may not be a gear pump at all.)
I think it is a gear pump. The ports are on the side and when I open
them up I can see a gear on the shaft and then another gear right
under it meshing with it. The situation is identical for each port. I
don't see any kind of check valve in either ports.
The check valves if it has them will be in the seal drain. Some
pumps are made to run either direction in this case there will be two
check valves for the seal drain so that high pressure isn't applied to
the seal. If the pump was just made to be turned one direction only
then there will only be one seal drain port and it will be on the
suction side of the pump. You might be able to see the seal drain hole
in the main ports but often the only way to see them is to take the
Well the ones that I have seen are simply spring loaded ball check
valves built into the casting. But in truth I've not seen that many
with that feature. I've seen a lot of pumps that are for one rotation
only (often with different sized ports) and these don't need the check
Could a hydraulic pump/motor and variable pressure accumulator be used to
collect the energy of descent of a bicycle and rider, and then by
cross-valving, propel them up the other side?
How much might such a system weigh, assuming a pump about 4 inches diameter and
5 inches long, chain driven from the rear wheel, and an accumulator of 100
cubic inches capacity?
What efficiencies might obtain in such a configuration?
I note that for reference, of 100% potential energy at the top of a say 200
foot hill, coasting to terminal speed, some 10% remains as kinetic energy at
the bottom. The rest warms great volumes of air by minute fractions of a degree
I seek to capture this energy and use it to light my cigarettes. :)
Doug Goncz ( ftp://users.aol.com/DGoncz/ )
Student member SAE for one year.
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