Hydraulic Formulas – FluidPower.Pro

Hydraulic Pump[ + ]
		Imperial	Metrical
Flow Rate	##Q=\frac{disp\cdot n\cdot E_{v}}{K\cdot 100}##	#Q# – Flow, gpm #disp# – Displacement, in.cu. #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 231	#Q# – Flow, lpm #disp# – Displacement, cm³ #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 1000
Displacement	##disp=\frac{Q\cdot K\cdot 100}{n\cdot E_{v}}##	#disp# – Displacement, in.cu. #Q# – Flow, gpm #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 231	#disp# – Displacement, cm³ #Q# – Flow, lpm #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 1000
Leakages (drain flow)	##Q_L=\frac{disp\cdot n\cdot (100-E_{v})}{K\cdot 100}##	#Q_L# – Drain Flow, gpm #disp# – Displacement, in.cu. #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 231	#Q_L# – Drain Flow, lpm #disp# – Displacement, cm³ #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 1000
Required Torque to provide the given pressure	##T=\frac{disp\cdot p\cdot100}{2\cdot \pi\cdot E_m}##	#T# – Torque, lb.-in. #disp# – Displacement, in.cu. #p# – Pressure, psi #E_{m}# – Mechanical Efficiency, %	#T# – Torque, Nm #disp# – Displacement, cm³ #p# – Pressure, MPa #E_{m}# – Mechanical Efficiency, %
Provided Pressure based on torque from engine	##p=\frac{2\cdot \pi\cdot T\cdot E_m}{disp\cdot100}##	#p# – Pressure, psi #T# – Torque, lb.-in. #disp# – Displacement, in.cu. #E_{m}# – Mechanical Efficiency, %	#p# – Pressure, MPa #T# – Torque, Nm #disp# – Displacement, cm³ #E_{m}# – Mechanical Efficiency, %
Power provided to the system	##P=\frac{Q\cdot p}{K}##	#P# – Power, hp #Q# – Flow, gpm #p# – Pressure, psi #K# = 1714	#P# – Power, kW #Q# – Flow, lpm #p# – Pressure, MPa #K# = 60
Power required from the engine	##P_{in}=\frac{Q\cdot p\cdot100}{K\cdot E}##	#P_{in}# – Power, hp #Q# – Flow, gpm #p# – Pressure, psi #E# – Overall Efficiency, % #K# = 1714	#P_{in}# – Power, kW #Q# – Flow, lpm #p# – Pressure, MPa #E# – Overall Efficiency, % #K# = 60
Efficiency	##\frac E{100}=\frac{E_v}{100}\cdot\frac{E_m}{100}##	#E# – Overall Efficiency, % #E_v# – Volumetric Efficiency, % #E_m# – Mechanical Efficiency, %	#E# – Overall Efficiency, % #E_v# – Volumetric Efficiency, % #E_m# – Mechanical Efficiency, %
Hydraulic Motor[ + ]
		Imperial	Metrical
Required Flow to provide the given rpm	##Q=\frac{disp\cdot n\cdot100}{K\cdot E_v}##	#Q# – Flow, gpm #disp# – Displacement, in.cu. #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 231	#Q# – Flow, lpm #disp# – Displacement, cm³ #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 1000
Displacement to provide the given rpm	##disp=\frac{Q\cdot K\cdot E_{v}}{n\cdot 100}##	#disp# – Displacement, in.cu. #Q# – Flow, gpm #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 231	#disp# – Displacement, cm³ #Q# – Flow, lpm #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 1000
Leakages (drain flow)	##Q_L=\frac{disp\cdot n\cdot(100-E_v)}{K\cdot E_v}##	#Q_L# – Drain Flow, gpm #disp# – Displacement, in.cu. #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 231	#Q_L# – Drain Flow, lpm #disp# – Displacement, cm³ #n# – Rotational speed, rpm #E_{v}# – Volumetric Efficiency, % #K# = 1000
Output Torque based on the motor inlet pressure	##T=\frac{disp\cdot p\cdot E_m}{2\cdot \pi\cdot100}##	#T# – Torque, lb.-in. #disp# – Displacement, in.cu. #p# – Pressure, psi #E_{m}# – Mechanical Efficiency, %	#T# – Torque, Nm #disp# – Displacement, cm³ #p# – Pressure, MPa #E_{m}# – Mechanical Efficiency, %
Required Pressure to provide the given torque	##p=\frac{2\cdot \pi\cdot T\cdot100}{disp\cdot E_m}##	#p# – Pressure, psi #T# – Torque, lb.-in. #disp# – Displacement, in.cu. #E_{m}# – Mechanical Efficiency, %	#p# – Pressure, MPa #T# – Torque, Nm #disp# – Displacement, cm³ #E_{m}# – Mechanical Efficiency, %
Power from the hyd. system	##P=\frac{Q\cdot p}{K}##	#P# – Power, hp #Q# – Flow, gpm #p# – Pressure, psi #K# = 1714	#P# – Power, kW #Q# – Flow, lpm #p# – Pressure, MPa #K# = 60
Power provided to the consumer	##P_{out}=\frac{Q\cdot p\cdot E}{K\cdot 100}##	#P_{out}# – Power, hp #Q# – Flow, gpm #p# – Pressure, psi #E# – Overall Efficiency, % #K# = 1714	#P_{out}# – Power, kW #Q# – Flow, lpm #p# – Pressure, MPa #E# – Overall Efficiency, % #K# = 60
Efficiency	##\frac E{100}=\frac{E_v}{100}\cdot\frac{E_m}{100}##	#E# – Overall Efficiency, % #E_v# – Volumetric Efficiency, % #E_m# – Mechanical Efficiency, %	#E# – Overall Efficiency, % #E_v# – Volumetric Efficiency, % #E_m# – Mechanical Efficiency, %