It takes more than just specifying size, speed rating, and torque range to assess the right coupling for an application. One of the most important factors is a coupling’s operating environment. The conditions a coupling will face can have a drastic impact on efficiency and service life. To learn more about a few environmental consideration basics, we asked Robert Watkins, VP of Sales for Ruland Manufacturing, for a few specific examples. Here is what he had to say.
For environmental considerations, we have temperature, moisture, chemicals and vacuum. These all need to be taken into consideration when selecting a coupling.
Example Number 1. I had an Aerospace customer using a coupling to control aperture on a telescope. They needed a coupling that could survive the vibration of takeoff, the vacuum of space, and extreme temperatures. The solution for this application was an oldham coupling with stainless hubs and a PEEK insert which is a special material we use on our oldham couplings that have extreme temperature capability and does not outgas.
Number 2. A medical customer required a coupling in an autoclave. They needed a coupling that could survive high temperatures for short intervals. The originally selected bellows coupling failed due to epoxy. Our bellows couplings have an epoxy so if you do exceed the temperature limit you will soften the epoxy and get a coupling failure. An oldham with a PEEK disc was a good choice for this solution as well.