Pump size,
Pump size,
(OP)
I need to calculate how large a hydraulic pump ( GPM @ 3000 psi ) I can run with a 75 BHP engine... what's the formula?
Also, would like to know how to caculate the BHP for hydraulic motors given cu.in./rev.,psi,gpm,rpm, and torque (in/lb).
Hope you can help, thanx bunches,
webbfoot
Also, would like to know how to caculate the BHP for hydraulic motors given cu.in./rev.,psi,gpm,rpm, and torque (in/lb).
Hope you can help, thanx bunches,
webbfoot





RE: Pump size,
bhp=Q*P/1714*E
where:
Q= flow rate
P=disch. press.
E=pump eff. as decimal
As for the motor appl. check with motor manufacturers via the web.
Hope this helps.
saxon
RE: Pump size,
bhp=2*pi*N*T/33000
where pi=3.1415926
N=shaft rotation rpm
T=torque ft-lbs
saxon's formula also applys to other pumps but that the pressure (psi) is normally replaced by head (ft) multiplied by specific gravity of fluid so that:
bhp=Q*H*sp/3960*E
RE: Pump size,
D=(2Pi.T)/P
P=(2Pi.T)/D
T=(PD)/2Pi.
Where D = Displacement in in3
T = Torque in lb–ins
P = Pressure in PSI
Pi = 3.1416
Or HP (output) = (Flow x PSI x et)/ 1714
Et = total eff which is mechanical eff. plus volumetric eff.
Ev varies with:
Higher with low pressures and falls with increase pressure
Highest at max speed
Em varies with:
Higher at low speed because of less friction
Higher at higher pressures because of better lubrication
Starting torque may be as high as 60% of running torque