electric driven ps pump ???

[artm]

This may sound stupid but what the heck...

is it practical to fit a battery driven ps pump? The thinking is obvious - to run a hydraulic winch off it. Even better, assuming the power requirement is met, would be to refit the existing pulley with a custom one having a clutch which can run off the battery when the engine's dead.

Seems that a motor running on several 10's of amps should do it instead of 100's for an electric winch.

Stupid???

[BarryO]

Seems that a motor running on several 10's of amps should do it instead of 100's for an electric winch.

From a conservation of enargy perspective, I don't see how this would work. How could 10's of amps all of a sudden do the work of 100's a amps? The hydrp winch would have to run very much slower than the electric winch.

[artm]

Well, as I see it...

1. much of the work of the electric winches is dissipated as heat due to the inefficiency of the system.

2. in a hydraulic setup you have the motor requiring about 2 amps, the engine running at idle - say 750 rpm - and driving the pump which does the majority of the work. That's the point of hydraulics. It generates much less heat which is easily dissipated, by the way, by the pump casing and the fluid.

So you can have a large amount of power driving an inefficient motor as in an electric setp or a small amount of electric power and a large amount of hydraulic power as in a hydraulic setup.

It seems possible to find a motor using 50 amps to run at 750rpm.

Of course, I could be wrong...but I hope not.

[Roadsiderob]

Art,
My day job involves working on forklifts...including electric models where they use electric motors to drive hydraulic pumps. As such, I am familiar with the size of electric motors required to drive even a small hydraulic pump. There are 2 problems with what you propose. First, the motors they use for this sort of thing are not small or light. I replaced an auxiliary pump motor yesterday and the motor weighed in at about 40 pounds and was 8 inches in diameter and 12 inches long. The power cables to these motors are the same as you would power an electric winch with. Secondly, 50ish amps may be realistic at 36volts or 48volts, but not at 12volts. I think that you would be looking at closer to 150-200amps.
There is no free lunch...until the Mr. Fusion becomes a reality.
Rob Dassler

[Buckon37s]

[QUOTE=artm]This may sound stupid but what the heck...QUOTE]

Your totally right, this does sound stupid :lol But really, like Rob got into a little, it will not even come close to working for tons of reasons. And, all that work for a hydra winch would not be worth it even if you could bend Gods laws.

[artm]

Check this out:

http://ca.autos.yahoo.com/030820/11/ugrz.html

"...TRW did make some systems in the early 80's, such as the Fiero that used an electric motor to drive the hydraulic power steering pump".

That sounds interesting! The research continues.

Follow-up Post:

More...


http://www.uccc.co.uk/when/hycwps.htm

" Electric Power Steering was first introduced in the mid 1970s"

http://www.classicperform.com/

"Electric Steering Pump"

http://www.mazdausa.com/MusaWeb/displayPage.action?pageParameter=perSteering

"The Electro-Hydraulic Power Assist Steering (EHPAS) System retains the hydraulics but is instead driven from an electric pump, mechanically independent of the engine."


Perhaps not so stupid after all.

[Mike Hippert]

Just a thought but how about a PTO driven pump off of the T-case?

http://www.4wdworld.com.au/products/maxidrive/hydraulicunit.htm

[artm]

The point is to run a winch without engine power. If this can be done with only 150A then why bother with an electric winch?

[Mike Hippert]

Hmmm, if you could get it to work at 150 amps 2 or 3 batteries would be dead real fast. Heav you seen the size of the batteries used on a forklift. They are like 300 lbs, and they don't last that long either if you are running the pump allot. You guys know that MileMarker also make a winch that runs off a small engine?

http://www.winchesplus.com/selfcontainedwinch.htm

[flippedrover]

Holy crap. Kind of cool in an overkill way too heavy way.

[evilfij]

Subarus had an electric P/S pump however the system will be less efficient that a pure electric system.

[Buckon37s]

OKay, I've been giving this some thought and I know how you can make this work. Two words, Cold Fusion.....

[artm]

I hoped that with a few amps the hydraulic part would be up to the task Doesn't look like it's possible so...

time to let go of the dream.