Twin City Fan & Blower 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.
Impeller and Shaft Maintenance
The buildup of material on axial flow impellers 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 impeller. This material can
come off in large chunks, throwing the impeller out of balance.
Clean the impeller and, on vaneaxial fans, the turning vanes; when
appropriate, apply new coatings.
If the impeller is removed for any reason, make sure that it
is securely attached to the shaft before restarting the fan. If the
impeller 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
7⁄811⁄2 850 71
11⁄811⁄813⁄41550 130
13⁄813⁄82 1700 141
15⁄815⁄821⁄42800 233
17⁄817⁄821⁄23900 325
21⁄821⁄823⁄45300 440
23⁄823⁄83 5600 470
27⁄827⁄831⁄26600 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
Figure 3. Solid Pillow Block Spherical Roller Bearing
Relubrication Schedule
*Suggested lubrication interval under continuous operation in adverse loading or with
elevated temperatures. For operation less than 24 hours per day or under ideal conditions,
lubrication frequency may be reduced. Relubricate while running, if safety 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 lithium-base grease having rust inhibitors and
antioxidant additives, and a minimum oil viscosity of 500 SUS at 100°F (38°C). Some
greases having these properties are:
Shell - Gadus S2 V100 2 Mobil - Ronex MP
Mobil - Mobilith SHC100 Mobil - Mobilith SHC220
2. Lubricate bearings prior to extended shutdown or storage and rotate shaft monthly
to aid corrosion protection.
3. Any lubrication requirements noted on the general assembly drawing supersede
requirements found here.
Fans with Unit Roller Bearings
Relubrication Schedule (Weeks)*
Spherical Roller Bearing - Solid Pillow Blocks
Shaft DIA Speed (RPM)
500 1000 1500 2000 2500 3000 3500 4000 4500
1⁄2" thru 17⁄16"
(13 – 35) 644211110.5
111⁄16" thru 23⁄16"
(40 – 55) 4 2 1.5 1 0.5 0.5 0.5 0.5 0.5
27⁄16" thru 37⁄16"
(60 – 85) 3 1.5 1 0.5 0.5 0.25 0.5 – –
315⁄16" thru 415⁄16"
(100 – 125) 2.5 1 0.5 0.25 – – – – –
WARNING
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 set screws for tightness and rotate
impeller by hand to make sure it has not moved in transit.
*Suggested lubrication interval under continuous operation in adverse loading or with
elevated temperatures. For operation less than 24 hours per day or under ideal conditions,
lubrication frequency may be reduced. Relubricate while running, if safety 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 lithium-base grease having rust inhibitors and
antioxidant additives, and a minimum oil viscosity of 500 SUS at 100°F (38°C). Some
greases having these properties are:
Shell - Gadus S2 V100 2 Mobil - Ronex MP
Mobil - Mobilith SHC100 Mobil - Mobilith SHC220
2. Lubricate bearings prior to extended shutdown or storage and rotate shaft monthly to
aid corrosion protection.
3. Any lubrication requirements noted on the general assembly drawing supersede
requirements found here.
Fans with Ball Bearings
Relubrication Schedule (Weeks)*
Ball Bearing Pillow Blocks
Shaft DIA Speed (RPM)
500 1000 1500 2000 2500 3000 3500 4000 4500
1⁄2" thru 111⁄16"
(13 – 45) 665332221
115⁄16" thru 27⁄16"
(50 – 60) 654221111
211⁄16" thru 215⁄16"
(65 – 75) 5432111––
37⁄16" thru 315⁄16"
(90 – 100) 4 3 2 1 1 – – – –
