Pulley Alignment - COOK TMX Installation, Operation And Maintenance Manual

Inlet Duct Turns
For ducted inlets, allow at least three effective wheel di-
ameters between duct turns or elbows and the fan inlet.
Correct
Incorrect
Inlet Duct Turns
Discharge Duct Turns
Where possible, allow three duct diameters between duct
turns or elbows and the fan outlet.
Discharge Duct Turns
Wheel-to-Inlet Clearance
The correct wheel-to-inlet clearance is critical to proper
fan performance. This clearance should be verified before
initial start-up since rough handling during shipment could
cause a shift in fan components. Refer to wheel/inlet draw-
ing below for correct overlap.
Adjust the overlap by loosening the wheel hub and mov-
ing the wheel along the shaft to obtain the correct value.
Trim balance as necessary following procedure (0.150 in/
sec max).
A uniform radial gap (space between the edge of the
cone and the edge of the inlet) is obtained by loosening the
inlet cone bolts and repositioning the inlet cone.
Wheel/Inlet Overlap
SEE DETAIL A
TMX IO&M
MIN
3 DIA
Correct
MIN
3 DIA
Incorrect
Size Overlap
(inches)
90
120
135
150
165
OVERLAP
180
RADIAL
202
GAP
225
245
270
300
330
DETAIL A
Belt and Pulley Installation
Belt tension is determined by the sound the belts make
when the fan is first started. The belts will produce a loud
squeal which dissipates after the fan is operating at full ca-
pacity. 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. This will result in a different fan speed.
1. Loosen motor plate adjustment bolts and move motor
plate in order that the belts can easily slip into grooves
on pulleys. Never pry, roll or force the belts over the
rim of the pulley.
2. Adjust the motor plate until proper tension is reached.
For proper tension, a deflection of approximately 1/4"
per foot of center distance should be obtained by firm-
ly pressing the belt. Refer to Figure 3.
3. Lock the motor plate adjustment nuts in place.
4. Ensure pulleys are properly aligned. Refer to Figure 4.

Pulley Alignment

Pulley alignment is adjusted by loosening the motor pul-
ley setscrew and by moving the motor pulley on the motor
shaft.
Tolerance
Center
Distance
Up through 12" 1/16"
12" through 48" 1/8"
Over 48"
Figure 4
Figure 4 indicates where to measure the allowable
gap for the drive alignment tolerance. All contact points
(indicated by WXYZ) are to have a gap less than the
5/32
tolerance shown in the table.
3/16
When the pulleys are not the same
3/16
width, the allowable gap must be
7/32
7/32
adjusted by half of the difference
7/32
in width. Figure 5 illustrates using
1/4
a carpenter's square to adjust the
9/32
position of the motor pulley until the
5/16
5/16
belt is parallel to the longer leg of
3/8
the square.
13/32
3
Figure 3
OFFSET ANGULAR
A
W
Max.
Gap
1/4"
CENTER
X
DISTANCE
(CD)
Y
Z
B
OFFSET/ANGULAR
GAP GAP
B51108-003