# Formula for Acceleration Torque - Objects in Rotary Motion

T_a   = (WK^2DeltaRPM)/(307t)

Enter Variables

• Rotational inertia of object,   WK^2   = lbs.-ft.^2
• Change in rot. speed,   DeltaRPM   = rpm
• Time period to accelerate,  t  = sec.
• Acceleration Torque, Rotary Motion,   T_a   = ft.-lbs.
• • For solid screw shaft, use   WK^2 = 1/8   WD^2, where W = weight of screw (lbs.), D = diameter of screw(ft.)
• † Formulas for acceleration torque and acceleration force are average values only for the time period values used. Actual peak torques and peak forces to accelerate can be several order of magnitude greater than formula values for short periods of time. The shorter the acceleration time period the greater actual peak values will exceed formula values. This can be important to designers when sizing drives and drive components.