What’s the difference between windup and backlash?

In this excerpt from a recent webinar with Robert Watkins, VP of Sales for Ruland Manufacturing, we learn about the key differences between windup and backlash. Watkins also touches on how to help deal with both. Here is what he had to say:

Windup is often confused with backlash; they are not the same. Backlash refers to power transmission error while windup is position error without torque error. All couplings have wind up. A windup failure occurs when a coupling with too much or too little windup is selected.

Backlash is actual clearance in the coupling itself, where there’s space between the spider and the jaws in a jaw type coupling. There is actually clearance there, which is error.

Some couplings do have windup or cushioning. A good example is spider couplings. With the spider of the different hardnesses of material, there’s no error, there’s no space between the spider and the hubs of the jaw but it does dampen, it does compress and that is wind up. It’s not an error, you wind up a spider coupling and that spider compresses. It rebounds, retains the torque and again that is not an error, its dampening or cushioning.

Ruland
www.ruland.com