Rockwell Automation 7000A PowerFlex Medium Voltage AC Drive (A Frame) - ForGe Control - Manual (Page 109)

Rockwell Automation Publication 7000A-UM200C-EN-P - June 2014 109
Component Definition and Maintenance Chapter 3
Installation of Impeller Assembly onto Motor Shaft
The fan impeller is held onto the motor shaft with a split tapered bushing. This
bushing is positioned on the motor shaft and through the center of the impeller.
Cap screws, when tightened to 10.2 N•m (7.5 lb•ft), lock the bushing onto the
motor shaft and the impeller to the bushing.
The bushing barrel and the bore of the impeller are tapered which assures
concentric mounting and keeps the impeller running evenly.
The cap screws, when tightened, lock the bushing in the impeller and over the
motor shaft.
The bushing is split down the middle, so that when the locking cap screws force
the bushing into the tapered bore in the impeller assembly, the bushing will grip
the shaft with a positive clamping fit.
The impeller and bushing assembly have keyways that line up with the shaft and
are held in place with compression.
To Assemble:
1. Make sure the shaft and keyway are clean and smooth. Clean the shaft and
bore with rubbing alcohol or non oily solvent. Check the key size with
both the shaft and bushing keyways.
2. Put the cap screws through the clearance holes in the bushing and put the
bushing loosely into the impeller, lining up the screws with the threaded
holes on the impeller hub.
3. Start the cap screws by hand, turning them just enough to engage the
threads. Do not use a wrench at this time. The bushing should be loose
enough in the impeller to move freely.
4. Slide the impeller and bushing assembly onto the motor shaft, ensuring the
same distance from the end of the shaft to the bushing as in step 1 of
impeller removal.
5. Fit the key into keyway. Do not force impeller and bushing onto shaft. If
they do not fit easily, check the shaft, bushing and key sizes.
6. Tighten the cap screws progressively with a wrench. Do this evenly as
though mounting an automobile wheel. Turn one a quarter turn, then the
next a quarter turn, then go back and turn the other a quarter turn and so on.
Torque to 10.2 N•m (7.5 lb•ft).
7. Peen the end of the motor shaft at the keyway with a chisel or center punch
to prevent the key from falling out of position.
IMPORTANT Do not press, drive or hammer the bushing into the bore.