Bearing Replacement - COOK PLC Installation, Operation And Maintenance Manual

Relubrication Intervals
Up to and
Including 184T
Service
1800
Conditions
Over
RPM
1800
and
RPM
Less Less
Standard 3 yrs. 6 months 2 yrs. 6 months
Severe 1 yr. 3 months
Motors are provided with a polyurea mineral oil NGLI #2
grease. All additions to the motor bearings are to be with
a compatible grease such as Exxon Mobil Polyrex EM and
Chevron SRI.
The above intervals should be reduced to half for vertical
shaft installations.
Motor Services
Should the motor prove defective within a one-year pe-
riod, contact your local Loren Cook representative or your
nearest authorized electric motor service representative.
Changing Shaft Speed
All belt driven fans with motors up to and including 5HP
(184T max) are equipped with variable pitch pulleys. To
change the fan speed, perform the following:
1. Loosen setscrew on driver (motor) pulley and remove
key, if equipped.
2. Turn the pulley rim to open or close the groove facing.
If the pulley has multiple grooves, all must be adjusted
to the same width.
3. After adjustment, inspect for proper belt tension.
Speed Reduction
Open the pulley in order that the belt rides deeper in the
groove (smaller pitch diameter).
Speed Increase
Close the pulley in order that the belt rides higher in the
groove (larger pitch diameter). Ensure that the RPM lim-
its of the fan and the horsepower limits of the motor are
maintained.
Pulley and Belt Replacement
1. Remove pulleys from their respective shafts.
2. Clean the motor and fan shafts.
3. Clean bores of pulleys and coat the bores with heavy oil.
4. Remove grease, rust or burrs from the pulleys.
5. Remove burrs from shaft by sanding.
6. Place fan pulley on fan shaft and motor pulley on its
shaft. Damage to the pulleys can occur when exces-
sive force is used in placing the pulleys on their re-
spective shafts.
7. Tighten in place.
8. Install belts on pulleys and align as described in Belt
and Pulley Installation.

Bearing Replacement

The fan bearings are pillow block ball bearings. Bearings
should be replaced individually for each side of fan.
An emery cloth or file may be needed to remove imper-
fections in the shaft left by the setscrews.
1. Remove belts.
2. If replacing drive side bearing, mark location of pulley
and remove.
3. Mark bearing location on bearing support and loosen
bearing hold down bolts.
PLC IO&M
Nema Frame Size
213T-365T 404T and Larger
1800
Over
RPM 1800 RPM
1800
and and Less
RPM
1 yr. 3 months
1 yr. 3 months 6 months 1 month
4. Support the shaft to remove weight from bearing.
5. Remove anti-corrosion coating from the shaft with a
suitable degreaser.
6. Remove the bearing from the shaft using a bearing
Over
puller. If a bearing puller is not available, tap on the
1800
RPM
bearing with a wood block and hammer to remove it.
7. Smooth and clean the shaft and bearing bore thoroughly.
8. Place the bearings into position making sure they are
not on a worn section of the shaft. Tapping the inner
ring face with a soft driver may be required.
Do not hammer on the housing.
9. The outer ring of the bearing is spherical and swivels
in the housing to compensate for misalignment. Se-
cure hold-down bolts, but do not fully tighten.
10. Align the setscrews on the bearings and tighten one
setscrew on each bearing.
11. Rotate the shaft to allow the bearing outer rings to find
their center of free movement.
12. Tighten hold-down bolts to proper torque as shown in
the Recommended Torque chart.
13. Turn the shaft by hand. Resistance should be the same
as it was before hold-down bolts were fully tightened.
14. Tighten bearing setscrews to specified torque (see
Recommended Torque chart).
15. Re-install the pulley and adjust the belt tension. Refer
to Belts and Pulley Installation.
16. Repeat the process for opposite bearing.
17. Adjust the belt tension.
18. Test run and retighten all setscrews and bolts. Trim
balance as necessary (.0785 in/sec max.).
After 24 hours of operation, retighten the setscrews to
the appropriate torque. This assures full locking of the in-
ner race to the shaft. Make sure the socket key or driver is
in good condition with no rounded corners. The key should
be fully engaged in the setscrew and held squarely to pre-
vent rounding out of the setscrew socket when applying
maximum torque.
Maximum Class Speeds of PLC
Size
120
135
150
165
180
195
210
225
245
270
300
330
365
402
445
490
540
600
660
730
6
Class 1 Class 2
4165 4768
3642 4137
3232 3669
2800 3289
2532 2980
2291 2722
2103 2504
1939 2317
1759 2112
1527 1895
1346 1685
1276 1558
1144 1392
1091 1286
965 1149
885 1031
782 929
738 843
650 753
576 658
Class 3
-
-
-
-
4101
3682
3333
3062
2732
2400
2233
1984
1772
1604
1484
1306
1190
1084
959
834
B51023-002