P O W E R T R A N S M I S S I O N P R O D U C T S
G E N E R A L I N F O R M A T I O N
117
G E N E R A L I N F O R M A T I O N
2 0 1 1
T
e c h n i c a l
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n f o r m at i on
B
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n s ta l l at i on
& T
e n s i on i n g
OBJECTIVE:
Goodyear Engineered Products Synchronous timing belts
must be installed and tensioned properly to ensure optimum
performance. Sprocket alignment must be preserved while
tensioning the drive.
Before beginning, inspect the belt for damage and verify that
the sprockets are properly mounted. Refer to sprocket and bush-
ing manufacturer installation procedure. Belts should never be
crimped or bent to a diameter less than the minimum sprocket
diameter, approximately 2.5 inches for 8mm belts and 5 inches
for 14mm belts.
1. Shorten the center distance or release the tensioning idler to
install the belt. Do not pry the belt onto the sprocket. Refer
to the following Center Distance Allowance tables for required
center distance adjustment.
Apply the following center distance allowances for the
Hawk Pd
®
and Falcon HTC
®
. A center distance adjust-
ment, or decrease in center distance, is necessary to install
a belt. In addition, an increase in center distance will be
necessary for proper tensioning. If you install a belt
together with sprockets, allow the following decrease in
center distance for installation and an increase in center
distance for tensioning.
If you install a belt over one flanged sprocket and one
unflanged sprocket with the sprockets already installed
on the drive, allow the following decrease in center dis-
tance for installation and increase in center distance for
tensioning.
Consider the following center distance allowances when
installing Eagle NRG
™
sprockets. Since flanges are not
necessary on Eagle NRG drives, only one table of center
distance allowances is provided.
Pitch Length
Range (mm)
Allowance (Decrease)
for Installation
8M, 14M Belts
(mm/in)
Allowance (Increase)
for Take-Up
8M, 14M Belts
(mm/in)
Less than 1525
2.5/0.1
2.5/0.1
1525-3050
5.0/0.2
5.0/0.2
Greater than 3050
7.5/0.3
7.5/0.3
Pitch Length
Range (mm)
Allowance (Decrease)
for Installation
8M Belts 14M Belts
(mm/in)
Allowance (Increase)
for Take-Up
8M, 14M Belts
(mm/in)
Less than 1525
22.5/0.9
36.5/1.4
2.5/0.1
1525 –3050
25.0/1.0
39.0/1.5
5.0/0.2
Greater than 3050 27.5/1.1
41.5/1.6
7.5/0.3
Pitch Length
Range (mm)
Allowance (Decrease)
for Installation
8M Belts 14M Belts
(mm/in)
Allowance (Increase)
for Take-Up
8M, 14M Belts
(mm/in)
Less than 1525
34.5/1.4
59.2/2.3
2.5/0.1
1525-3050
37.0/1.5
62.0/2.4
5.0/0.2
Greater than 3050 39.5/1.6
64.5/2.5
7.5/0.3
Pitch Length
Range (mm)
Allowance (Decrease)
for Installation
8M Belts 14M Belts
(mm/in)
Allowance (Increase)
for Take-Up
8M, 14M Belts
(mm/in)
Less than 1525
10.1/0.4
15.2/0.6
2.5/0.1
Greater than 1525 15.2/0.6
17.8/0.7
5.0/0.2
2. Place the belt on each sprocket and ensure proper engagement
between the sprocket and belt teeth.
3. Lengthen the center distance or adjust the tensioning idler to
remove any belt slack.
4. Using a tape measure, measure the span length of the drive.
Refer to dimension “P” in the diagram below. The span length
can be calculated using the below formula.
Shorter Center Distance
for Synchronous Installation
Center Distance
Longer Center Distance
for Synchronous Belt Take-Up
If you install the belt over two flanged sprockets that
are already installed on the drive, allow the following
decrease in center distance for installation and increase
in center distance for tensioning.