A "Sleeve Coupling" is pretty straight forward, if you look at the picture above. Some instances refer to this coupling as a "Muff Coupling" or maybe a "Split Muff Coupling", probably referring to the shape of the coupling in comparison to a "Muff" used to keep one's hands warm in colder climates. In either case, it is basically a piece of round steel stock, (maybe even considered a pipe) bored to some internal dimension (as necessary), usually having a keyway cut, then the sleeve is cut in half and bolts (or in this case) cap screws bored and threaded to hold the two halves together. In smaller units, the method of "attachment" to the shafts may simply be an "Allen Set Screw". Usually that set screw is positioned over the keyway so that it tightens onto the key to hold it in place, also. If we talk about REALLY SMALL sleeves, they may only have the set screw and rely totally on that object to transmit the torque as well as hold the coupling in place. In this case we're talking here about "micro" or "mini-fractional" horsepower motors and equipment. That's it!
And while this is the simplest of "Sleeve Couplings", there are certainly modifications and hybrids that do the same thing but with somewhat different characteristics. One thing that all of them will have in common is that they are part of the "Rigid Coupling" family. When this coupling is bolted together around two mating shafts, there isn't any room for flexibility and/or misalignment. Transmission of power is 100% with no loss due to friction or flexing of the torsional member... 'cause there simply isn't any! Based on the fact that angular and parallel alignment is a REAL issue, we definitely recommend Laser Alignment or expert dial indicator alignment of equipment at installation.
A final note on the "Sleeve Coupling" has to do with a hybrid that we find in numerous pieces of equipment requiring repair. Specifically, the shaft coupling on hoist motors designed by Reuland on various manufacturer's hoists and cranes. This coupling is a "Sleeve" but rather than being split, and having a smooth (or keyed) bore, this "Sleeve Coupling" is "splined" it's entire bore length. Again, this is just an example of a hybrid on a specific application.
A.R.&E. can assist you in the proper selection of any application requiring a "Sleeve Coupling". So give us a call.