Drive sheave replacement, Bearing maintenance, Important – Greenheck EQB (479049) User Manual
Page 7
Mixed Flow Inline Fan
7
loose or too tight) or misaligned sheaves. Abnormally
high belt tension or drive misalignment will cause
excessive bearing loads and may result in failure of
the fan and/or motor bearings. Conversely, loose belts
will cause squealing on start-up, excessive belt flutter,
slippage and overheated sheaves. Either excessively
loose or tight belts may cause fan vibration.
1. Belts tend to stretch after a period of time. They
should be checked periodically for wear and
tightness. When replacing belts, use the same
type as supplied with the unit.
2. Matched belts should always be used on units with
multi-groove pulleys.
3. For belt replacement, loosen the tensioning device
enough to allow removal of the belt by hand. Do
not force belts on or off. This may cause cords to
break, leading to premature belt failure. Do not
install new belts on worn sheaves. If the sheaves
have grooves worn in them, they must be replaced
before new belts are installed.
4. Once installed, adjust belts as shown in
“Prestart-up Checks”.
Drive Sheave Replacement
Drive components supplied by Greenheck Fan Corp.,
have been carefully selected for this unit’s specific
operating condition. Changing drive components
could result in unsafe operating conditions which may
cause personal injury or failure of fan components.
1. Remove the protective coating from end of the fan
and motor shafts using mineral spirits or another
similar solvent. Check to ensure that the shaft is
free of nicks and burrs. Remove old sheaves.
2. Slide sheaves on shafts. Do not drive sheaves on
as this may result in bearing damage.
3. Align fan and motor sheaves with a straight-edge
or string and tighten.
4. Place belts over sheaves. Do not pry or force belts,
as this could damage the cords in the belts.
5. Adjust the tension until the belts appear snug. Run
the unit for a few minutes (refer to unit start-up
section) and allow the belts to “set” properly.
6. With the fan off, adjust the belt tension by moving
the motor plate; Belts are adjusted by raising or
lowering the motor plate. When in operation, the
tight side of the belts should be in a straight line
from sheave to sheave with a slight bow on the
slack side.
Bearing Maintenance
The bearings for Greenheck fans are carefully
selected to match the maximum load and operating
conditions of the specific class, arrangement and
fan size. The instructions provided in this manual
and those provided by the bearing manufacturer will
minimize any bearing problems. Bearings are the
most critical moving part of the fan. Therefore, special
care is required when mounting them on the unit and
maintaining them.
IMPORTANT
Lubricate bearings prior to periods of extended
shutdowns or storage and rotate shaft monthly to
aid in preventing corrosion. If the fan is stored more
than three months, the bearings should be purged
with new grease prior to start-up.
TABLE 4
Grease Manufacturers
Mobil Oil Corporation
Mobilith SHC 220
Mobilith AW2
Shell
Shell Alvania #2
Texaco, Inc.
Texaco Multifak AFB2
Texaco Premium RB
Exxon
Exxon Unirex N2
Refer to Tables 3 and 4 below and the manufacturer’s
instructions for grease types and intervals for various
operating conditions. Never mix greases made with
different bases. This will cause a breakdown of the
grease and possible failure of the bearing.
NOTE: Suggested initial greasing interval is based
on 12 hour per day operation and 150º F. (66ºC)
maximum housing temperature. For continuous
(24 hour) operation, decrease greasing interval
by 50%. If unusual environment conditions exist
(extreme temperature, moisture or contaminants)
more frequent lubrication is required.
1. If possible, relubricate with grease while in
operation without endangering personnel.
2. Ball bearings (operating): Relubricate until clean
grease is seen purging at the seals. Be careful not
to unseat the seal by over lubricating.
3. Ball bearings (idle): Add one to two shots of grease
up to 2 inch (51 mm) bore sizes, and four to five
shots of grease above 2 inch (51 mm) bore sizes
with hand grease gun.
4. Adjust lubrication frequency based on condition of
purged grease.
5. A high quality lithium base grease conforming to
NLGI Grade 2 consistency, such as those listed in
Table 4, should be used.
TABLE 3
Recommended Fan Bearing Lubrication Schedule (in Months)
Fan
RPM
Bearing Bore
- Dimensions in inches
(mm)
1
⁄
2
- 1
1
1
⁄
8
- 1
1
⁄
2
1
5
⁄
8
- 1
7
⁄
8
1
15
⁄
16
- 2
3
⁄
16
2
7
⁄
16
- 3
3
3
⁄
16
- 3
1
⁄
2
3
15
⁄
16
- 4
1
⁄
2
(13-25) (29-38) (41-48) (49-56) (62-76) (81-89) (100-114)
To 250
6
6
6
6
6
5
4
500
6
6
6
5
4
3
3
750
6
5
4
3
3
2
2
1000
6
4
3
2
2
1
1
1250
5
3
2
1
1
0.5
0.5
1500
5
2
1
1
0.5
0.5
0.25
2000
5
1
1
0.5
0.25
0.25
0.25
2500
4
0.5
0.5
0.25
0.25
0.25
3000
4
0.5
0.25
0.25
0.25
®