Hydraulic Formulas -Motors

HydraulicPump. Formulas andEfficiency.

Effo= Overall Efficiency(Power, KW)Effv=Volumetric Efficiency(Flow, LPM)Effm=Mechanical Efficiency(Torque, Nt-m)QReal= QTheoreticalXEffoTInput= TTheoretical/EffmHPInput= HPTheoretical/Effo

HydraulicAccumulatorFormulas.

Boyle Law, Isothermal change of state of gases.(The change in the gasvolumetakes place soslowlythat there is sufficient time for the complete exchange of heat between the N2 and the exterior. At constant temperature)P1x V1= P2x V2Where:P1= Initial GasPressure(Psia)V1= Initial Gas Volume (in3)P2= Final Gas Pressure (Psia)V2= Final Gas Pressure (in3)Psia = Psig + 14.7 psiAdiabatic change of state of gases.(The change in the gas volume takes place sorapidly that the temperature of the N2 also changes)P1x (V1)n= P2x (V2)nWhere:n = Molar specific heat ratio for N2(Nitrogen) = 1.4

Finding the size of the accumulator needed:Adiabatic change ( fast charge & discharge)P1= Gas Pre-chargeV =V1-V2= Available Volume for DischargeP2= Maximum System pressuren = 1.4 forN2V1= [P2/P1]1/1.4xV2

ReservoirFormulas.RESERVOIRVOLUME:

RECTANGULAR RESERVOIR VOLUMEROUND RESERVOIR VOLUME

VOL(Gals)=L(in) xD(in) x0.785xH(in) / 231VOL(Gallons)=D2(in2) x0.785xH(in) / 231

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COOLING CAPACITY OF THE TANK:

RECTANGULAR RESERVOIRROUND RESERVOIR

SURFACE AREA(ft2)= ASURFACE AREA(ft2)= A

2 xL(ft) xD(ft) + 2 xL(ft) xH(ft) + 2 xD(ft) xH(ft)1.5708 xD2(ft2)+ 3.1416 xD(ft) xH(ft)

TD(oF) =Temperature Differencebetweensurrounding Air and Oil inside.

COOLING POWER(HP) = 0.001 xTDxACOOLING POWER(HP) = 0.001 xTDxA

Formulas applied to Cylinders.Double Acting Cylinders.For Single acting Cylinders, use "Going OUT" Formulas.

Formulas applied to Cylinders.Double Acting Cylinders.For Single acting Cylinders, use "Going OUT" Formulas.