What environmental factors influence coupling selection?

Understanding the myriad environmental variables a coupling might encounter is crucial during early the design stages of your motion system. We spoke with Bobby Watkins from Ruland Manufacturing to help us identify some of the environmental consideration design engineers should keep in mind. He gives a few real-world examples to explain.

“Environmental considerations include temperature, moisture, chemicals, vacuum — all important things to consider at the time of selection. What are we dealing with in all these different issues? For example, in one situation, an aerospace customer was using a coupling to control aperture on a telescope. They needed a coupling that could survive the vibration of an actual spacecraft during takeoff. Other factors included handling the vacuum of space, extreme temperatures, and no outgassing. In this case, we went to 316 stainless steel Oldham hubs and a special non-outgassing PEEK Oldham insert.

In another application example, we were looking into an autoclave’s environment. A Medical customer required a coupling in an autoclave. They needed a coupling that could survive high temperatures for short intervals. We originally selected a bellows, but again the temperature in the autoclave exceeded the temperature capability of the epoxy and the solution to this was again an Oldham with a PEEK disk. The disk not only does not outgas, but it could also withstand high temperature.

Ruland
www.ruland.com