electric motor with hydraulic pump?

[lostcause]

i've looked at two stage splitter pumps and they generally give you a "gas engine" size that is recommended to operate them. is this directly proportional to using an electric motor with one, or is there a difference in what will work?

also, are there any electric motor frame types that will hook to a pump in the same fashion as an small engine, such as a bracket and lovejoy style coupler or similar direct drive style?

what i'm looking to reproduce is something like the electric hydraulic powerpacks that are sold, but the ones i have seen are lower power and flow than i am looking for. i'm also not interested in immediate purchase, but just knowing what will work with what, so if i were to come across a suitable used electric motor or pump, then i could pick it up.

it's an indoor application to drive a 5" to 6" diameter, 8" stroke cylinder. i like the idea of the two stage pump as it would give faster lead and return times, but then kick over to the power stage when it hits the load.

 

[LD1]

A search may be your friend. This has been discussed and there are many different opinions as to what will work and what will work but not for long.

This may get you started. http://www.tractorbynet.com/forums/hydraulics/162627-electric-motor-5hp-gas-log-2.html

The question about style of motor though, basically you have two types. A c-face and a base mount. Either of which you will have to make an adapter to bolt it in place. A C-face bolts around the end that the shaft is on in a circular pattern. Base/frame mount has a mount with holes on the side.

 

[Craig Clayton]

To lostcause
I built an electric powered hydraulic wood splitter 20 years ago. On a 4 " cylinder I apply 2000 psi on a hi /low pump. The motor is 2 Hp at 220 volt. Look on Williams hydraulic pumps. My splitter is taken apart at the moment because I do not need it.
Craig Clayton

 

[oldnslo]

i've looked at two stage splitter pumps and they generally give you a "gas engine" size that is recommended to operate them. is this directly proportional to using an electric motor with one, or is there a difference in what will work?

Generally you can use a little smaller electric motor since they are more efficent. formula for figuring HP required is: (GPM x PSI) / (1714 x % efficiency) I typically divide by 1500.

also, are there any electric motor frame types that will hook to a pump in the same fashion as an small engine, such as a bracket and lovejoy style coupler or similar direct drive style?

C-face motors with mounting feet. You can purchase a bell housing from several different sources that will allow you to bolt the pump and motor together using Love Joy type couplings.

Search for Vescor or MacMillian Hydraulics as two sources for the bell housing.

what i'm looking to reproduce is something like the electric hydraulic powerpacks that are sold, but the ones i have seen are lower power and flow than i am looking for. i'm also not interested in immediate purchase, but just knowing what will work with what, so if i were to come across a suitable used electric motor or pump, then i could pick it up.

it's an indoor application to drive a 5" to 6" diameter, 8" stroke cylinder. i like the idea of the two stage pump as it would give faster lead and return times, but then kick over to the power stage when it hits the load.

 

[LD1]

Generally you can use a little smaller electric motor since they are more efficent. formula for figuring HP required is: (GPM x PSI) / (1714 x % efficiency) I typically divide by 1500.

Just to clarify for you, that is the formula for electric motor HP. If a gas motor were to be used, I think it is something like 1.5x or 2x more HP.

Also, if you plan on using a 2-stage pump, you need to figure the HP twice. A 16GPM 2stage pump ISNT 16GPM @ 3000psi.

So for a Haldex 16gpm 2-stage the specs are85% eff)
16 gpm @ 650psi which would require 7.13HP
3.5gpm @ 2500psi which would require 6 HP

So you would need a 7.5HP Motor.

A haldex 11gpm 2-stage (85% aswell)
11gpm @ 650 would require 4.9HP
2.9gpm @2500 would require 4.97 HP

A 5HP motor would work with this pump.

If you get a heavy duty motor with a SF of 1.15 or higher, you could probabally use the 5HP on the 16gpm pump and be fine since it isnt at is max continuously.

A smaller motor than the ones i listed will work, but not last. A motor is rated for how many amps it can pull. A motors locked rotor amp draw is about double that. So it won't stall like a gas motor if you go too small. It will just draw more current than it was designed to. And it will butn up in no time.

 

[lostcause]

great information to digest so far guys. i think i'm going to try to work with a 5hp motor as a maximum & i had been looking at probably the same 11 gpm 2 stage pump.

i've go to do a little more research and see what is used on similar commercial units and see whether i'm going over or coming in about where they are. if i could cut down to a 3hp and get by with a smaller pump, it would give me more motor choices, since the larger you go, the scarcer used motors are, and generally any that size are likely to be 3 phase, and then i'll have to go with a vfd too... one more thing i know nothing about, lol.

 

[LD1]

great information to digest so far guys. i think i'm going to try to work with a 5hp motor as a maximum & i had been looking at probably the same 11 gpm 2 stage pump.

i've go to do a little more research and see what is used on similar commercial units and see whether i'm going over or coming in about where they are. if i could cut down to a 3hp and get by with a smaller pump, it would give me more motor choices, since the larger you go, the scarcer used motors are, and generally any that size are likely to be 3 phase, and then i'll have to go with a vfd too... one more thing i know nothing about, lol.

IMO I would shoot for the 5HP/11gpm combo. On a 4" cylinder they give pretty good cycle times. Any smaller of a pump, the cycle times get a good bit slower.

 

[lostcause]

IMO I would shoot for the 5HP/11gpm combo. On a 4" cylinder they give pretty good cycle times. Any smaller of a pump, the cycle times get a good bit slower.

that was my gut, but i almost think i've seen used industrial units with 3hp motors. i may be way off on the pump too. to be honest, i'm not even sure if a 2 stage pump is a workable design. it just seems logical to me to be able to move the tool up to the work at a good rate of speed, and then have it kick down a gear to do the heavy lifting, so to speak. i need to find a way to get inside a machine to see what makes them tick i guess.

 

[RadarTech]

that was my gut, but i almost think i've seen used industrial units with 3hp motors. i may be way off on the pump too. to be honest, i'm not even sure if a 2 stage pump is a workable design. it just seems logical to me to be able to move the tool up to the work at a good rate of speed, and then have it kick down a gear to do the heavy lifting, so to speak. i need to find a way to get inside a machine to see what makes them tick i guess.

ya know this makes me wonder why we don't see Electrically driven hydraulic top links...

If the spools cost $300 and the hoses cost $50 per..
and the cylinders are the same... why couldn't the electrically driven be cheaper??

J

 

[lostcause]

ya know this makes me wonder why we don't see Electrically driven hydraulic top links...

If the spools cost $300 and the hoses cost $50 per..
and the cylinders are the same... why couldn't the electrically driven be cheaper??

J

older jd gators used linear actuators for the dump body which are really not much more than an electrically driven screw. they look just like a hydraulic cylinder, but i dont think there's any way you can get one to come close to the capacity a straight hydraulic cylinder. with tractors you already have the pump and hydraulics on hand, so that's the easy way to go.

to do electric like i am, it's only the start of the equation. the electric motor drives a hydraulic pump, fueled by a reservoir, into a valve, powering a cylinder. lots more parts and money involved to go electric when you have hydraulic on hand already.