How to Prevent Damage to Your Servo When Removing a Coupling
Posted by Michael Norman on Fri, Oct 02, 2009 @ 02:57 PM
The Coupling on your motors shaft needs to be removed or put back on. You grab a hammer and some prybars....
First off, put the hammer and the prybars back. Your servo has very sensitive feedback sensors installed in the motor. These devices are attached directly to the shaft and are easily damaged. Any hammering could break the glass of an encoder. Prying on the coupling could also break glass or drive the rotor of a resolver into the servomotors endbell destroying it. In order to remove your coupling easily, there are a few things to evaluate about it.
Are there any setscrews or bolts on the end of the shaft. Take the time to clean the coupling and look. If you find one setscrew there are probably more. Pulling the coupling off of the shaft without removing setscrews will damage the shaft.
Does your coupling have threaded holes that can be used as backdrives? Many couplings have compression rings that can be pushed apart using the backdrive holes. This will allow you to pull the coupling off by hand.
Use a puller, not prybars. Using a puller will move the coupling in relation to the shaft. Prybars will pull the shaft and the coupling away from the motor possibly damaging the bearings and/or feedback. If you put alot of force on the puller and the coupling still will not budge then try adding some quick heat to the coupling. If you can heat the coupling before the shaft the expansion will help free the coupling.
These are some tips to remove a coupling from the shaft while minimizing possible damage to your servomotor.