Hydraulic basics. Can someone steer me?

[tedzap]

I have a press and a tube bender which use air over hydraulic cylinders. I am thinking about building a diy iron worker out of a vintage plate shear which would also use hydraulic power. Could I use an electric hydraulic pump to power multiple devices? There is a local selling the pump from a dock lift, would this be a good candidate?

guess I am looking for cliffs notes regarding hydraulic power units.

thanks in advance.

 

[u3b3rg33k]

if you want to select a power unit, and you're not ordering out of the book for your tool from the manufacturer, at a minimum you need to know how much pressure you need, how much flow, and if you need directionals.

if you know exactly what you need, you can find one on ebay for a song. I picked up a used power unit with a piston pump for less than the price the pump lists for.

 

[tedzap]

It looks like the pump is model P1AAN2022. The only thing I have found is greek to me. Can anyone put these specs into english for a layman? Does this give me the pressure and flow capacity?


Elektropumpe 220/380V, 50Hz, 1,1kW, 6-polig Motor:1,1KW,230/400V,50Hz BG90,B3/B5, n= 910U/min, von AC-Motoren GmbH Hydr.-Zahnradpumpe P1AAN2022FL20A01N vg=22,87cm³/U, Qmax=20,8l/min Pumpenträger PK200/3/3, Kupplung Rotex19 (dm 24/15,875)

 

[txvwnut]

It looks like that pump is a 5gpm pump which for moving a hydraulic cylinder would probably be adequate depending on how large the cylinders are and how fast you want them to move. You can operate multiple machines from one pump but not all at the same time unless your supply pump is large enough to handle it.

 

[seber]

Translation
Electric pump 220/380V, 50Hz, 1.1kW, 6-pole Motor: 1.1KW, 230/400V, 50Hz BG90, B3/B5, n= 910rpm, from AC-Motoren GmbH Hydraulic gear pump P1AAN2022FL20A01N vg=22.87cm³/rev, Qmax=20.8l/min Pump housing PK200/3/3, Rotex19 coupling (dm 24/15.875)

 

[tedzap]

I found another specification chart. Is this reasonable for pushing cylinders of the size I am looking at? Thanks.

spec chart for P1AAN2022 - page 15




Capacity 22.87 cm3/t

Peak pressure 175 bar (2500 psi)

Max working
Pressure 150 bar (2175 psi)

Max speed 3500 rpm

Flow @
1500rpm 34.2 lpm (9 gpm)

@ 3500rpm 79.8 lpm (21 gpm)

Power absorbed
@ 1000 rpm
and 100 bar 4.48 kw (6 hp)

Absorbed Torque
@ 100 bar 42.78 N-m (31.5 ft-lbs)

 

[Shoreline_]

What cylinder and how many of them?

 

[PCustoms]

@tedzap what is your location?

 

[tedzap]

I am in Roanoke, Virginia. I don't have the cylinders yet, they will be acquired to convert from air/hydrauilic cylinders.

 

[Shoreline_]

I am in Roanoke, Virginia. I don't have the cylinders yet, they will be acquired to convert from air/hydrauilic cylinders.

Weeeeelllll how much tonnage do you want and whats the dimensions of your lever arm or are they direct acting?

 

[Firebrick43]

A 6 pole 50hz motor is going to turn around 1000 rpm on 60hz and give you around 6 Gpm.

Not going to set any speed records but will work

You need to decide if 2500 psi is sufficient. It’s an ok pressure but you will need to use larger cylinders to get your desired tonage

Say you want your cylinder to achieve 20 tons at 2500 psi it would take a 4.5” cylinder to achieve that and have a 8” extend time of 5.3 secs or 1.5” per second

Increasing the cylinder to 6” diameter increases tonnage to 35 tons of force but increases time to extend 8” to 10 seconds

 

[Shoreline_]

Exactly. I went through this with our shop owner back when we wanted to build our own. Then it was a rabbit hole. Like lets find a 100 ton setup, cut the end off and have a prefill valve. Then use small cylinder to raise and lower the ram. Oy vey. We just ended up with a used dake.

 

[u3b3rg33k]

Exactly. I went through this with our shop owner back when we wanted to build our own. Then it was a rabbit hole. Like lets find a 100 ton setup, cut the end off and have a prefill valve. Then use small cylinder to raise and lower the ram. Oy vey. We just ended up with a used dake.

better to get a variable piston pump with a torque limiting valve. moves fast then throttles back displacement when it's time for pressure. quiet, too.

like a PVP16 CONTROL OPTION “H”
of course that pump probably costs more than the whole press.

I managed to replace a 6hp motor+pump combo with a 2HP motor+pump combo by only having it do what I needed (pressure compensated) instead of pouring over a relief 24/5.

 

[Shoreline_]

better to get a variable piston pump with a torque limiting valve. moves fast then throttles back displacement when it's time for pressure. quiet, too.

like a PVP16 CONTROL OPTION “H”
of course that pump probably costs more than the whole press.

Youd think right? The amount of hp to send down a ram like 7" in diameter as fast as we wanted was like a 50hp motor. Faster with a prefill valve and positioning cylinders and a lot smaller pump. We also couldve used proportional spools but mimicking how the big presses do it made more sense.

 

[u3b3rg33k]

Youd think right? The amount of hp to send down a ram like 7" in diameter as fast as we wanted was like a 50hp motor. Faster with a prefill valve and positioning cylinders and a lot smaller pump. We also couldve used proportional spools but mimicking how the big presses do it made more sense.

I got u!

https://www.ebay.com/itm/226132227295