Rockwell Automation 7000 PowerFlex Medium Voltage AC Drive (B Frame) - Classic Control - Manual (Page 349)

Component Definition and Maintenance 6-59
7000 “B” Frame 7000-UM150I-EN-P – June 2013
Impeller Maintenance (cont.)
1. Record the distance from the end of the motor shaft to the
bushing. The new impeller must be installed in the same
location. Failure to do so will result in gaps between the
impeller and the intake ring resulting in loss of air flow, or
rubbing of the impeller against the inlet ring or motor assembly
during operation.
2. Remove both capscrews from the bushing. The impeller or
bushing may fall as screws are loosened.
3. Thread the capscrews by hand into the two threaded holes in the
bushing flange.
4. Tighten each bolt part of a turn successively, to push the impeller
off the bushing. Screwing down the capscrews into these holes
will force the bushing away from the impeller hub, releasing the
compression on the shaft. Be careful that the impeller does not
fall as the clamping force is released.
5. Pull the bushing off the shaft and remove the impeller. If the
assembly has been in place for some time, it may be necessary to
use a wheel puller to remove the bushing. Never use a wheel
puller on the impeller.
NOTE: DO NOT LUBRICATE CAPSCREWS, BORE, OR
BUSHING BARREL, AS THIS WILL HINDER CLAMPING
FORCE OF THE BUSHING ON THE SHAFT AND THE
IMPELLER BORE
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. Capscrews, when tightened to 10.2 N-m
(7.5 ft-lbs.), 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 capscrews, 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
capscrews 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.