Does a standard GM Power Steering pump put out enough pressure to drive say
a ram in a hydraulic press? If so, what HP motor would be needed to drive
the pump? Pulley ratio? Anyone been there done that? :-)
I know the ZF pump in my older BMW is considered bad if it can't make better
than 1400 PSI with the pressure gauge stuck right on the output.
ZF made the power steering in lots of different cars, so it is possible that
there is one of those in a GM car.
-- Joe
--
Joseph M. Krzeszewski Mechanical Engineering and stuff
snipped-for-privacy@wpi.edu Jack of All Trades, Master of None... Yet
MileMarker hydraulic winches run off the power steering pump of the
vehicle... there is some flow & pressure information listed that should give
some idea of what a stock pump is capable of:
The reservoir volume will generally be quite small unless you fab up a new
tank...........
Unless you are using double acting cylinders, you will need to take this
into consideration.
As to horsepower, IIRC, that is an energy / time measurement, one horse can
do the same work as two, it just takes a longer time is all--this is where
your pulley ratio comes into play.
I built a tubing bender for square tubing with a power steering pump
from a ford truck. It uses a 2.5" cylinder and will bend up to 2"x2"
HSS into a 90 degree bend. After that it slips the belt and stalls the
pump. Not bad for free. I run it with a 1/2hp 1825 rpm electric motor
at about a 1:1 ratio. The resevoir may have to be enlarged to move a
bigger ram. They develop enough pressure but they are not that fast.
Let's see, 2.5" cylinder, 8" stroke takes about 6 seconds to extend.
Should put it in the range of 1.7 gpm.
Jason Marshall
A company makes a hydraulic powered winch for vehicles. I considered
getting one for my old '82 Chevy Diesel 1/2 ton, but didn't. They
tapped off the high pressure line on the power steering pump and ran a
winch rated at 12,000 lbs, if I recall correctly.
Since the pumps run a single v-belt, the power is less than 10 hp.
Remember, the pressure may be high, but the volume is limited. you
need to think about your application requirements.
Paul
Marty Escarcega wrote in article
...
When I was a kid - some 35-40 years ago - we used to use an Oldsmobile P/S
pump to run a snowplow lift cylinder on a pickup truck.
There were a number of snowplows out there with a hand-pump hydraulic unit
similar to a bottle jack or Porta-Power that we would convert for a few
dollars.
The Olds P/S pump developed 1300 p.s.i. and did a very adequate job.
OTOH - my Pro-Tools tubing bender uses a foot-pedal-operated,
air-over-hydraulic pump that develops 20,000 p.s.i.
You should be able to come up with something in between for your purposes.
Use "mechanical advantage" that hydraulics can offer. 1300 p.s.i. applied
to one-square-inch of piston area will result in 1300 pounds of force from
that piston.
The same 1300 p.s.i. applied to a two-square-inch piston area will result
in 2600 pounds of output force.
Etc, etc, etc.....
Of course, twice as much fluid will be required to move the two-square-inch
piston the same distance as the one.
Bob Paulin - R.A.C.E.
Chassis Analysis Services
[posted and mailed]
snipped-for-privacy@mb.sympatico wrote in
news: snipped-for-privacy@4ax.com:
Very cool. Might you have pictures or a sketch of your design? My
intention is to make the hydraulic unit portable, in otherwords be able
to move it from my Hossfeld style bender to the hydraulic press.
Would be interested in seeing what you did for the design of your bender.
Perhaps you can take some photos and post them in the RCM Drop Box?
Thanks
Marty
On Mon, 23 Feb 2004 13:33:07 GMT, Marty Escarcega
vaguely proposed a theory
......and in reply I say!:
Depends what you mean.
I was under the impression that steering stuff puts out 1000-1500 PSI,
whereas "hydraulic cylinders" a la FELs etc use 2000-3000 PSI.
I also thought that jacks, and cylinders in porta powers are rated for
much higher pressures, to keep size down for a given push.
For instance a 10 tonne porta power has a cylinder that is about
_maybe_ 1 1/4 inches in diam. This equates to around 8000 PSI to get
10 tonne. 10,000 PSI rating comes to mind for these machines.
On the other hand the jack in a 12-tonne press is maybe 2.25" diam.
This brings it back down to the 2500-3000 PSI mark. **************************************************** sorry
.........no I'm not!
remove ns from my header address to reply via email
Spike....Spike? Hello?
Power steering pumps can span a big range from as low as 800 PSI up to
3000 PSI . It is real easy to tell the high pressure ones as they look
like reg hydralic pumps . Had a high pressure one on an 86 Chev 4X4
dually . It blew hoses real regularly and also powered the power brake
unit . It is not hard to up the pressure on the reg style though .
On Tue, 24 Feb 2004 00:58:06 -0800, Ken Cutt
vaguely proposed a theory
......and in reply I say!:
OK. Interesting. I suppose press work is not exactly heavy-duty. BUt
you are placing the pump under pressures it was not meant for.
Anyway, thanks for that.
**************************************************** sorry
.........no I'm not!
remove ns from my header address to reply via email
Spike....Spike? Hello?
Most power steering pumps have spring loaded valves to prevent over
pressurization.
The intermitent duty of press work should be no bother to the pump.
Besides, they are everywhere and cheap. If it dies, it dies.
Ron Thompson
Was On the Beautiful Mississippi Gulf Coast,
Now On the Beautiful Florida Space Coast, right beside the Kennedy Space Center,
USA
formatting link
The ultimate result of shielding men from the effects of folly is
to fill the world with fools.
--Herbert Spencer, English Philosopher (1820-1903)
On Tue, 24 Feb 2004 13:54:20 -0600, Ron Thompson
vaguely proposed a theory
......and in reply I say!:
The whole point of the posted site was to "adjust" the valve with
washers to cause vast overpressure. That was my concern. **************************************************** sorry
.........no I'm not!
remove ns from my header address to reply via email
Spike....Spike? Hello?
Heh, heh! I haven't done it to a power steering pump but my
buddies did it to an engine oil pump. Any idea what 200 psi does
to the average screw-on oil filter? Especially with the hood off
to NOT contain the resulting spray? You should have seen the
looks on their faces. LOL!
Old Nick wrote:
On Wed, 25 Feb 2004 00:30:30 -0600, Roy J
vaguely proposed a theory
......and in reply I say!:
Old diesel sump oil?
**************************************************** sorry
.........no I'm not!
remove ns from my header address to reply via email
Spike....Spike? Hello?
On Wed, 25 Feb 2004 20:32:44 GMT, snipped-for-privacy@hotmail.com (Roy) vaguely
proposed a theory
......and in reply I say!:
I couldn't find any mention of hydro pumps and motors etc. Can you
give us a lead which susbtitle?
TIA
**************************************************** sorry
.........no I'm not!
remove ns from my header address to reply via email
Spike....Spike? Hello?
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