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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
120
G E N E R A L I N F O R M A T I O N
T
e c h n i c a l
I
n f o r m at i on
Synchronous belts are very sensitive to misalignment. The
tension carrying member has a high tensile strength and resistance
to elongation, resulting in a very stable belt product. Any
misalignment will lead to inconsistent belt wear, uneven load
distribution, and premature tensile failure. In general,
synchronous drives should not be used where misalignment is a
problem. Misalignment should be limited to
1
/
4
degree or
1
/
16
inch
per foot of center distance.
With parallel shafts, misalignment occurs when there is an offset
between the sprocket faces as in Figure A. Misalignment also
occurs when the shafts are not parallel as in Figure B.
Any degree of misalignment will reduce belt life and cause edge
wear. Therefore, a straightedge should be used to check proper
alignment verifying that sprockets and shafts are parallel, as in
Figure C.
Correct Alignment
A straightedge should touch the sprocket at the four points
indicated. Both front and back alignments should be checked.
Laser Alignment Tool
Goodyear Engineered Products Laser Alignment Tool provides an
alternative to checking alignment with a straightedge. Each laser
alignment tool comes with a rugged carrying case and detailed
instructions to get you started with the quickest, easiest, and most
versatile alignment tool on the market today.
Figure A
Misaligned
Figure B
Figure C
Aligned
D
r i v e
A
l i g nm e n t
Misalignment, at times, may cause tracking problems. Although
some tracking is normal and will not affect belt performance, it
may be caused by poorly aligned sprockets. Flanges may control a
tracking problem. Considering a two-sprocket drive, belt contact
on a single flange is acceptable. Belt contact with the opposite
flanges of two sprockets should be avoided.
Aligned
Misaligned
Misalignment can also be attributed to the improper installation
of a bushing or loose drive framework. Refer to sprocket manufac-
ture guidelines for proper bushing installation. Secure motor and
framework to eliminate vibration on center-to-center fluctuations.