COOK VCR - Manual (Page 5)

5
Maximum RPM
Replacing Pulleys and Belts
a. Clean the motor and fan shafts.
b. Loosen the motor plate mounting bolts to relieve the
belt tension. Remove the belt.
c. Loosen the pulley setscrews and remove the pulleys
from the shaft.
If excessive force is required to remove the pulleys, a
three-jaw puller can be used. This tool, however, can
easily warp a pulley. If the puller is used, inspect the
trueness of the pulley after it is removed from the
shaft. The pulley will need replacement if it is more
than 0.020 inch out of true.
d. Clean the bores of the pulleys and place a light coat of
oil on the bores.
e. Remove grease, rust and burrs from the pulleys.
f. Place fan pulley on the fan shaft and the motor pulley
on the motor shaft. Damage to the pulleys can occur
when excessive force is used in placing the pulleys on
their respective shafts.
g. After the pulleys have been correctly placed back onto
their shafts, tighten the pulley setscrews.
Belt and Pulley Installation
Belt tension is determined by
the sound of the belts when the
fan is first started. The belts
will produce a loud squeal,
which dissipates after the
fan is operating at full
capacity. If belt tension is
too tight or too loose,
lost efficiency and
damage can occur.
Do not change the
pulley pitch diameter
to change tension. The
change will result in a different
fan speed.
a. Loosen motor plate adjustment bolts
and move motor plate so that the belts easily slip into
the grooves on the pulleys. Never pry, roll, or force the
belts over the rim of the pulley.
b. Slide the motor plate back until proper tension is
Size
VCR VCR-HP
VCR-XP
Standard Reinforced Standard Reinforced
100 2002 -
120 1671 -
135 1574 -
150 1520 - 1952 -
165 1295 - 1728 - 2508
180 1546 - 1829 - 2396
195 1353 - 1570 - 2100
210 1227 - 1626 - 2126
225 1086 - 1435 - 1879
245 901 - 1185 1234 1616
270 766 - 1025 1049 1656
300 837 877 980 1046 1391
330 716 748 830 912 1182
365 624 659 735 872 1132
402 539 560 -
445 463 473
490 360 403
OFFSET ANGULAR OFFSET/ANGULAR
A
W
X
Y
Z
B
CENTER
DISTANCE
(CD)
GAP GAP
reached. For proper tension, a deflection of approxi-
mately 1/4” per foot of center distance should be
obtained by firmly pressing the belt. Refer to Figure 1.
c. Lock the motor plate adjustment bolts in place.
d. Ensure pulleys are properly aligned. Refer to Figure 2.
Pulley Alignment
Pulley alignment is adjusted by loosening the motor pul-
ley setscrew and by moving the motor pulley on the motor
shaft.
Figure 2 indicates where to measure the allowable gap
for the drive alignment tolerance. All contact points (indi-
cated by WXYZ) are to have a gap less than the tolerance
shown in the table. When the pulleys are not the same
width, the allowable gap must be adjusted by half of the dif-
ference in width. Figure 3 illustrates using a carpenter’s
square to adjust the position of the motor pulley until the
belt is parallel to the longer leg of the square.
Figure 2
1 foot
1/4 inch
Figure 1
Center Distance
Maximum
Gap
Up thru 12” 1/16”
12” up through 48 1/8”
Over 48” 1/4”
Figure 3