Fan speed, Replacement, Changing fan speed – COOK SQI User Manual

Page 5: Pulley and belt replacement, Bearing replacement, Wheel replacement, Maximum rpm

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5

Changing Fan Speed

All belt driven fans with motors up to and including 5 HP

are equipped with variable pitch pulleys.

a. Loosen setscrew on motor pulley.
b. Open or close the groove facing to change the pitch

diameter.

Speed Reduction - Open the pulley in order that the

belt rests deeper in the groove.

Speed Increase - Close the pulley in order that the

belt rests higher in the groove. Ensure RPM limits
of the fan and the horsepower limits of the motor
are maintained.

c. Retighten pulley setscrew on one of the flat areas of

the motor shaft.

d. After the adjustment is made, check for proper belt

tension. See the Belt and Pulley Installation section.

Pulley and Belt Replacement

a. Remove pulleys from their respective shafts.
b. Clean the motor and fan shafts.
c. Clean bores of pulleys and coat the bores with heavy

oil.

d. Remove grease, rust, or burrs from the pulleys and

shafts.

e. Remove burrs from shaft by sanding.
f. Place fan pulley on fan shaft and motor pulley on its

shaft.

NOTICE! Do not hammer the pulleys onto the shafts
because this may damage the bearings.

g. Tighten in place.
h. Install belts on pulleys and align as described in the

Belt and Pulley Installation section.

Bearing Replacement

The SQI-B fan bearings are pillow block ball bearings.

a. Remove outer access door.
b. Remove bolts/screws to inner housing access doors.

Open and remove the inner access door to reveal
bearings.

c. Remove the old bearing.
d. Remove any burrs from the shaft by sanding.

Maximum RPM

SQI-B

Size

Maximum RPM

SQI-HP

Size

Maximum RPM

90

3341

135

2624

120

2966

150

2692

135

2460

165

2687

150

2209

180

1958

165

2158

195

1901

180

1814

210

1702

195

1590

225

1797

210

1417

245

1775

225

1490

270

1525

245

1485

300

1271

270

1244

330

1208

300

1041

365

1000

330

992

402

995

365

833

402

714

e. Slide new bearings onto the shaft to the desired loca-

tion and loosely mount bearings onto the bearing sup-
port. Bearing bolts and setscrews should be loose
enough to allow shaft positioning.

f. Correctly position the wheel and tighten the bearing

bolts securely to the bearing plate.

g. Align setscrews bearing to bearing and secure tightly

to the shaft.

NOTICE! Never tighten both pairs of setscrews

before securing bearing mounting bolts. This may
damage the shaft.

h. Inspect the wheel position again. If necessary, read-

just by loosening the bearing bolts and setscrews and
repeat from step e.

Wheel Replacement

a. Drill two 1/4” diameter holes, 180

 apart centered

approximately between the shaft and the outside
diameter of the hub, 3/8” to 1/2” in depth.

b. Tap 1/4” holes to 5/16” thread with a 5/16” hole tap.

Do not drill or tap greater than recommended.

c. Screw the puller arms to the full depth of the threads

into the tapped holes. Align center of the puller with
the center of the shaft. Ensure all setscrews in the
hub, normally two, are fully removed.

d. Slowly remove wheel from the shaft.

Recommended Puller

Lisle No. 45000 Sterling Wheel Puller. This puller is avail-

able at most automotive parts retail outlets.

Above - Drilled hole placement.

Right - Wheel puller.

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