Aerovent IM-101 - Manual

©1997 Aerovent
V-Belt Drive
Proper alignment and balance of the V-belt is as important as
a well-balanced impeller. To insure smooth fan operation, the
following should be checked:
1. Fan and motor sheave must be in axial alignment. Shafts
are parallel in both the vertical and horizontal planes
(Figure 1).
2. Fan motor sheave must be in radial alignment. When
sheaves are of equal width, align with straightedge (Figure
1a). When sheaves are of unequal width, align center of
sheaves (Figure 1b).
3. Sheaves must have no noticeable eccentricity.
4. Belts must have the proper tension. Belts either too loose
or too tight cause vibration and excessive wear (Figure 2).
See IM-100 for belt tension adjustment procedure.
5. After proper installation of drives, recheck complete
assembly for smoothness of operation. Recom-
mended vibration limits shown on page 2 of IM-100.
Alignment
Flexible Couplings
Direct-coupled fans, which are received factory assembled, on
a common base plate, are accurately aligned before shipment.
However, base plates are flexible to some extent and therefore
must not be relied upon to maintain the factory alignment.
Realignment is necessary after the fan has been leveled, grout-
ed, and the foundation bolts tightened. Also, check lubricant,
where applicable, following manufacturer’s recommendations
for type and amount of lubricant.
For field installation, the coupling should be mounted as
follows:
1. Remove dirt or rust from fan and motor shafts and coat
with grease or oil for ease of mounting.
2. Check fan and fan shaft alignment, making sure that bear-
ings are secure. Mount fan shaft coupling half flush to end
of shaft and secure.
3. Mount motor shaft coupling half flush to end of shaft and
secure.
4. Move motor into position, with the coupling faces sepa-
rated by the coupling manufacturer’s specified gap.
5. With a straightedge, tapered wedge, or a feeler gauge, check
for parallel and angular alignment (Figure 2a).
6. Align the shafts until a straightedge appears to be parallel
to the shafts. Repeat at three additional points at approxi-
mately 90° from each other (Figure 2b). Recheck hub sepa-
ration gap.
7. For more accurate alignment, use a dial indicator clamped
on one hub. With the dial button resting on the other hub,
rotate the hub on which the indicator is clamped and
observe the indicator reading. Take readings at four loca-
tions, 90° apart. With correct alignment, the faces of the
couplings should be parallel within .002".
8. Once proper alignment is assured, secure the motor, exam-
Figure 1
Figure 1a Figure 1b
Figure 2
Figure 2a Figure 2b
General Installation, Operation and Maintenance Instructions For Aerovent Products
IM-101
June 1997