Coupling smooths packer's pick-and-place motion (sidebar)

Regarding the servo-driven motion, Stan Johnson, Schneider Packaging’s vice president of engineering says, “this combination of horizontal and vertical motions, especially at high speeds, can be very damaging to the system’s timing belt. We needed to position a coupling between the case packer servo motor and the speed reducer/timing belt that would provide the horizontal linear motion and compensate for backlash and any offset between motor and speed reducer. “We considered bellows-type couplings, but ruled them out as they were too ‘mushy’ for this application. We needed ‘torsional’ rigidity in our design connection to eliminate any possibility of backlash that could affect the servo control.” Even a little “play” such as an extra ½ degree rotation in a rotary system, he adds, translates to “a lot of motion” in a linear system. Thus, the Zero-Max coupling provides the accurate motion transfer required.