Disc couplings are an excellent choice when selected for the proper application. We asked Bobby Watkins of Ruland Manufacturing to give us some insight on general coupling selection. The following is an excerpt from the disc coupling section of his Webinar, Master Coupling Selection: A Guided Journey by Bobby Watkins. Specifically, Watkins covers different styles of disc couplings and which to select for different applications.
There are a few different options for this. There is an electrically isolating type available, that centerpiece assembly that’s sitting in between the discs, which kind of holds the whole assembly together. We can do that in a non-metallic material, which we’d give you again some low voltage electrical isolation if required.
Some of the drawbacks. Complicated assembly increases cost. There’s a good amount of work to putting one together. There’s a lot going on there. If you take a look at it, you’ve got your two hubs, you’ve got your center member assembly. You’ve got sets of wafers on either side. It’s a relatively complicated design, if you will. Rivets are sometimes used to join hubs to disc, causing excess wear on the disc springs, reducing coupling life. Basically, steel washers or wafers, and then wafers are riveted together or screwed together into that center member and into the hub.
Over time, the hole where the rivet or the screw goes to can oval out over repeated use. When that hole, the hole’s oval out, now you’ve got some slop in the coupling. You’ve got some error because of the oversized holes where the rivets go through and again, the potential is there for you to be making bad product because you’ve got an error in your coupling but you’re still connected. It’s still running. Again, great coupling, great characteristics, probably a good idea to have a maintenance, not a maintenance program but a replacement program. Who knows? Every couple of years, every three years. It depends on the application where you just go in and replace it.