Hydraulic Fluid Calculations

Pump useful output power = pressure rise x volumetric flowrate (all in compatible units).

Do you know the displacement per rev of the pump? I think you will need that info.

What does the nameplate say?

Greg

If memory serves me correctly, hydaulic horsepower expressed in terms of flow in GPM and pressure in PSI is: Horsepower = (PSI X GPM)/1714. This is theoretical, and does not account for losses which may be 30% additional or so.

Berniek

Hydraulic Motors: H.P.= torque output (inch pounds) x RPM /63025; solve for torque.

Once you solved the Torque you can solve for displacment by Torque= PSI x Displacment (cu. Inch per rev) / (2 x 3.14)

Once you have displacement in cu. Inch per rev, mult displacement times the rpm you want at the motors then divide by 231 will convert the cubic inches into gpm.

Hydraulic Pumps: H.P. = PSI x GPM / 1714 x Pump Eff.

Remember, it will take more h.p. in then you will get at the motor shaft out.

It will make a big difference on input based on how you plumb the motors; series or parallel.

1 H.P. = 550 ft.lbs / sec.

Work done per engine = 56 x 550 ft.lbs = 30800 ft lbs / sec.

Assume Mech. Eff. = 0.8 ; Hydraulic Efficiency = 0.7

Actual work done on the fluid = 30800 x 0.8 x 0.7 = 17248 ft.lbs./sec. = 206976 in. lbs. / sec.

Assume Pressure in psi = p ; displacement in in³ = d

work done = p x d x 2000 / 60 in. lbs. / sec.

equating the two expressions for work done

we get p x d = 206976 x 60 / 2000 = 6210 in. lbs. / stroke

There are two variables p and d. You must know one of the variables to decide the other.

If p = 40 psi then d = 6210 / 40 = 155 in³

Rate of flow = 155 x 2000 / 1728 = 180 Cubic ft. per min.

Kash,

Very well depicted you must be a teacher. I had to copy this info for further refrence myself.

Thanks

All hydraulic motors have a rating:

IE: GPM at xxxPSI = xxx RPM / xxx TORQUE.

If you do not have it go to the manufactures web site and get it!

Then you will know what the flow and pressure requirements are that YOU need.

To solve any problem you first have to identify the problem.