Calculating hydraulic pressure, help.

[rijidij]

I'm looking at building a small hydraulic press brake for my workshop, hopefully using parts I already have.
I have a cylinder with a 4" bore and a pump as in the picture. I've tried to find details of this pump online without success. Can anyone tell from the numbers on the pump what the capacity of the pump is, and then how to calculate the pressure on the cylinder.

Thanks for any help.

Cheers Murray

https://www.aulro.com/afvb/images/imported/2017/09/942.jpg

[rijidij]

I do have another pump which is physically larger.
The only markings on it are some numbers stamped into the housing.
2-115-A
846
731
V752https://www.aulro.com/afvb/images/imported/2017/09/941.jpg

[workingonit]

Have you seen this? I'm guessing from the chart the model is 16. Looks like pressure stuff further down in article. Pressure seems to be determined by the strength of the motor driving it.

http://uk.rs-online.com/webdocs/002f/0900766b8002f92e.pdf

[Dorian]

Hi Murry
Let me know if i'm telling you what you already know. My hydraulic guy tells me the PDF is about right, its for a different series pump, however except for the 22 the numbers should be the same.

With your small pump you've have a 16 cc/rev, a standard motor (3 phase) should spin at 1500 rpm ish giving you 24l/min.
From the Mr Google Hydraulic Formulas - Berendsen Fluid Power (http://www.berendsen.com.au/resources/hydraulic-calculators/hydraulic-formula-calculator/)
Rearranging the formula Pressure (bar) = Power (Kw) x 600 / Flow (L/Min)

if you've got a 1kw motor it's going to stall ( or you need to set your relief at ) at 25 bar or 367 PSI (14.7 PSI to 1 bar)
4 inch cylinder is going to give you 4600lb ( 2150kg ) on the backside of the ram.

Hope this helps and my calc's are right

Cheers Glen

[Rick1970]

^^ this sounds about right without doin the calcs.

Work out what sort of cylinder force and speed you need at the pressbrake, then work back from there. Pump/motor sizing is the last part. You have 3-phase available?

[justinc]

^^ this sounds about right without doin the calcs.

Work out what sort of cylinder force and speed you need at the pressbrake, then work back from there. Pump/motor sizing is the last part. You have 3-phase available?

^^^^^

Jc

[roverrescue]

Murray
Amongst the jibberish there are some links and maths in this thread

Largeish Hydraulic Press Build (https://www.aulro.com/afvb/projects-and-tutorials/185119-largeish-hydraulic-press-build.html)


Since that thread I've made a 1200mm wide press brake that uses commercial tooling
I only have one upper and lower die but use different size angle for wid lower dies


But FYI running a chingaling 5hp single phase 2800rpm motor to a 6cc/rev gear pump
To a similar hydraulic ram I can press brake the following...

4mm Al full width 1200mm

5mm steel ~400mm width
8mm steel ~100mm width
10mm steel not quite