Hydraulic Motor Calculations

Displacement from Measurements (inches)

Theoretical cubic inches displacement per shaft revolution (C.I.R)?
Formula: 6*W*(2*D-L)*(L-D)/2 = CIR

GPM of Flow Needed for Fluid Motor Speed

Example: How many GPM are needed to drive a 3.75 cubic inch motor at 1500 rpm?
Formula: Motor Displacement x Motor RPM / 231 = gpm

Fluid Motor Speed from GPM Input

Example: How fast will a 3.75 cubic inch motor turn with 24.35 gpm input?
Formula: 231 x GPM / Fluid Motor Displacement = RPM

Fluid Motor Torque from Pressure and Displacement

Example: How much torque does a 2.5 cubic inch motor develop at 2000 psi?
Formula: PSI x Motor Displacement / (2 x Π) = torque in inch pounds

Fluid Motor Torque from Horsepower and RPM

Example: How much torque is developed by a motor at 12 horsepower and 1800 rpm?
Formula: Horsepower x 63025 / RPM = torque in inch pounds

Fluid Motor Torque from GPM, PSI and RPM

Example: How much torque does a motor develop at 1500 psi, 1200 rpm with 10 gpm input?
Formula: GPM x PSI x 36.77 / RPM = torque in inch pounds