Using the representative range of sliding friction losses, these curves include double the torque required for acceleration (to compensate for leaving the inlet pressure system on and continuing to power the OHIO OSCILLATOR during deceleration with a throttle discharge) plus the coefficient of friction values indicated. The maximum torque required from the OHIO OSCILLATOR rotary actuator, for moving a weight, is given approximately by the following equation:
(T/W) = 0.3 (R/t)2 + R CfL (I + CfA2)1/2 lb-ft torque/lb weight
Where R is the torque arm length (feet), t is the time for a rotation of 1800 (seconds) CfL and CfA are the coefficents of friction of the moving weight (horizontally) and the torque arm slide (vertically). Although T = lb-ft we have converted the values shown graphically on these curves to lb in of torque per lb of weight moved for the two frictional conditions.
To select the torques required to transfer a 100 lb load a distance of 6 ft in 3 seconds, assuming a coefficient of friction of 0.05, refer to the OHIO OSCILLATOR HARMONIC MOTION TORQUE CURVE for low friction. Reading up from 3 sec to the R = 3 ft (6 ft diameter = 3 ft radius) curve, you then read to the left column to 5.7 lb-in of torque per pound to be moved. Multiply 5.7 x 100 lb = 570 lb-in torque for acceleration, deceleration, and friction. That's very little torque for that much work!
Likewise, moving the same load in one second would require 35 lb-in per lb of load or 3500 lb-in of torque.
Now let us examine the same load, but assuming a cooefficient of friction of 0.25 using the OHIO OSCILLATOR HARMONIC TORQUE CURVE for high friction. Following the same procedure, a speed of 3 seconds requires 13 lb-in per lb of load, or a total of 1300 lb-in of torque, and 1 second requires 40 lb-in per lb of load, or a total of 4000 lb-in of torque.
Note: The foregoing curves were developed from theoretical considerations to illustrate how to select an OHIO OSCILLATOR rotary actuator for a specific application. OHIO OSCILLATOR does not intend, nor do we imply, that these same performance characteristics will prevail in your application, and the curves are to be used as guides only.