Twin City Engineering Supplement ES-191
3
Bearing Lubrication
Proper lubrication of belt drive bearings helps assure
maximum bearing life. All fans are equipped with decals
indicating relubrication intervals for normal operating
conditions. However, conditions at every installation are
different and the frequency of relubrication should be
established accordingly. Figure 2 shows the relubrication
schedule for ball bearings. Figure 3 shows the
relubrication schedule for solid pillow block spherical
roller bearings.
Lubrication intervals should be doubled on fans with
vertical shafts.
On high moisture applications, the relubrication
frequency may need to be doubled or tripled to
adequately protect the bearings. Carefully replace the
joint sealant under the bearing access cover whenever
the bearings on high moisture fans are serviced.
Observation of the condition of the grease expelled
from the bearings at the time of relubrication is the best
guide as to whether regreasing intervals and the amount
of grease added should be altered.
Greases are made with different bases. There are
synthetic base greases, lithium base, sodium base, etc.
Avoid mixing greases with different bases. They could
be incompatible and result in rapid deterioration or
breakdown of the grease.
All bearings are filled with a lithium based grease
before leaving the factory. When the fans are started,
the bearings may discharge excess grease through the
seals for a short period of time. Do not replace the initial
discharge because leakage will cease when the excess
grease has worked out. Bearings have a tendency to
run hotter during this period and should not be a cause
for alarm unless it lasts over 48 hours or gets very hot.
When relubricating, use a sufficient amount of grease
to purge the seals. Rotate bearings during relubrication
where good safety practice permits.
Propeller and Shaft Maintenance
The buildup of material on axial flow propellers can
adversely affect fan performance. While fans that handle
clean, fresh air seldom need cleaning, occasionally
check fans used for industrial purposes for material
buildup on the propeller. This material can come off
in large chunks, throwing the propeller out of balance.
Clean the propeller and, on vaneaxial fans, the turning
vanes; when appropriate, apply new coatings.
If the propeller is removed for any reason, make sure
that it is securely attached to the shaft before restarting
the fan. If the propeller is attached to the shaft by
means of a Trantorque
®
bushing, use the tightening
torque values shown in Table 1.
Table 1.
TRANTORQUE
®
SHAFT
SOCKET
TORQUE
TORQUE
SIZE
DIA.
SIZE
(IN. LBS.)
(FT. LBS.)
7
⁄
8
7
⁄
8
1
1
⁄
2
850
71
1
1
⁄
8
1
1
⁄
8
1
3
⁄
4
1550
130
1
3
⁄
8
1
3
⁄
8
2
1700
141
1
5
⁄
8
1
5
⁄
8
2
1
⁄
4
2800
233
1
7
⁄
8
1
7
⁄
8
2
1
⁄
2
3900
325
2
1
⁄
8
2
1
⁄
8
2
3
⁄
4
5300
440
2
3
⁄
8
2
3
⁄
8
3
5600
470
2
7
⁄
8
2
7
⁄
8
3
1
⁄
2
6600
550
Note: These torque values are to be obtained with a calibrated torque
wrench. DO NOT apply any lubricant to any part of the Trantorque
®
hub. DO NOT use an anaerobic thread adhesive such as Loctite
®
on
the threads.
Figure 2. Ball Bearing Relubrication Schedule
1. This equipment must not be operated without proper guarding of
all moving parts. While performing maintenance be sure remote
power switches are locked off. See AMCA Publication 410 for
recommended safety practices.
2. Before starting: Check all setscrews for tightness, and rotate wheel
by hand to make sure it has not moved in transit.
*Suggested initial greasing interval: Rotate bearings during relubrication
where good safety practice permits until some purging occurs at seals.
Adjust lubrication frequency depending on condition of purged grease.
Hours of operation, temperature, and surrounding conditions will affect
the relubrication frequency required.
1. Lubricate with a high quality NLGI No. 2 or No. 3 multipurpose
ball bearing grease having rust inhibitors and antioxidant additives.
Some greases having these properties are:
Shell - Gadus S2 V100 2 Mobil - Mobilith AW2/Mobilith SHC100
Gulf - Gulfcrown No. 2
American - Rykon Premium 2
2. Lubricate bearings prior to extended shutdown or storage and
rotate shaft monthly to aid corrosion protection.
WARNING
Relubrication Schedule (Months)*
Ball Bearing Pillow Blocks
Speed (RPM)
500 1000 1500 2000 2500 3000 3500 4000 4500
Shaft DIA
1
⁄
2
" thru 1
11
⁄
16
"
6
6
5
3
3
2
2
2
1
1
15
⁄
16
" thru 2
7
⁄
16
"
6
5
4
2
2
1
1
1
1
2
11
⁄
16
" thru 2
15
⁄
16
"
5
4
3
2
1
1
1
3
7
⁄
16
" thru 3
15
⁄
16
"
4
3
2
1
1
1
Figure 3. Solid Pillow Block Spherical Roller Bearing
Relubrication Schedule
1. This equipment must not be operated without proper guarding of
all moving parts. While performing maintenance be sure remote
power switches are locked off. See AMCA Publication 410 for
recommended safety practices.
2. Before starting: Check all setscrews for tightness, and rotate wheel
by hand to make sure it has not moved in transit.
*Suggested initial greasing interval: Rotate bearings during relubrica-
tion where good safety practice permits until some purging occurs at
seals. Adjust lubrication frequency depending on condition of purged
grease. Hours of operation, temperature, and surrounding conditions
will affect the relubrication frequency required.
1. Lubricate with a multipurpose roller bearing NLGI No. 2 having rust
inhibitors and antioxidant additives, and a minimum oil viscosity of
500 SSU at 100ºF. Some greases having these properties are:
Shell - Gadus S2 V100 2 Mobil - Mobilith AW2/Mobilith SHC100
Texaco - Premium RB2
American - Rykon Premium 2
2. Lubricate bearings prior to extended shutdown or storage and
rotate shaft monthly to aid corrosion protection.
WARNING
Relubrication Schedule (Months)*
Spherical Roller Bearing - Solid Pillow Blocks
Speed (RPM)
500 1000 1500 2000 2500 3000 3500 4000 4500
Shaft DIA
1
3
⁄
16
" thru 1
7
⁄
16
"
6
4
4
2
1
1
1
1
1
⁄
2
1
11
⁄
16
" thru 2
3
⁄
16
"
4
2
1
1
⁄
2
1
1
⁄
2
1
⁄
2
1
⁄
2
1
⁄
2
1
⁄
2
2
7
⁄
16
" thru 3
7
⁄
16
"
3
1
1
⁄
2
1
1
⁄
2
1
⁄
2
1
⁄
4
1
⁄
4
3
15
⁄
16
" thru 4
15
⁄
16
" 2
1
⁄
2
1
1
⁄
2
1
⁄
4
