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© 2011 Gates Corporation
EZ ALIGN is a registered trademark of Gates Corporation
MACHINE PREPARATION
Before commencing any work ensure basic safety rules are
adhered to.
Loose clothing or long hair must never be allowed
anywhere near belt-driven machinery. All equipment MUST
be locked out and tagged out.
CAUSES OF BELT FAILURE
Before beginning any pulley alignment, causes of belt or pulley
failure must be examined and corrected to prevent recurrence.
Causes of failure could include poor drive maintenance (wrong
belt tension, pulley misalignment), environmental factors
(sunlight, harsh temperature fluctuations), improper installation
(wrong belts/sheaves, belts forced onto grooves), or operating
factors (overload, shock load).
INSPECTION
Perform a visual inspection of the belts and of each pulley and
its grooves. Look for and feel for cracks, chips, or excessive
groove wear. Proper contact between the belts and the pulleys
must be ensured.
Worn belts or pulleys and other components should be
replaced before proceeding with pulley alignment.
PULLEY ALIGNMENT
SOFT FOOT
Inspect the moveable machine for “soft foot”.
Feeler gauges
can be used under a loosened foot to measure the gap. Shim
the machine foot with the largest amount of gap (the amount
indicated with the feeler gauges) until no reading is larger than
0.05mm (0.002” or 2 mils). Use precut 304 stainless steel
shims. Severe “soft foot” distorts the machine frame when
bolted down, causing damage to seals and bearings. It could
also lead to high vibration levels on the machine bearings.
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© 2011 Gates Corporation
EZ ALIGN is a registered trademark of Gates Corporation
DRIVE BELTS
The condition of the worn belt is a good indication of the type of
misalignment or other problems that may be present. Belts
must be changed as soon as undue wear is detected. For a
multiple-belt drive, all belts must be replaced together. Only
belts from the same manufacturer should be combined
together in order for the belts to share the load equally.
In order to replace the belts on a belt drive system, they must
first be loosened. This is often accomplished by simply
loosening the driver or driven unit and reducing the center
distance. In other cases, an idler pulley may need to be
loosened and moved. Belts must never be forced or rolled onto
a pulley as this can damage the pulley as well as the belt
tensile cord.
New belts must be properly stored. They should be kept in a
cool, dry place with no exposure to direct sunlight or heat. They
also should not be hung from single pegs. For further
information, refer to Gates “Belt Drive Preventative
Maintenance & Safety Manual”.
PULLEYS
If installing new pulleys and belts ensure that the correct-belt-
pulley combination and the correct size belts have been
selected. Existing pulleys should be inspected carefully for
wear and replaced if necessary. Consult the Gates “Belt Drive
Preventative Maintenance & Safety Manual”.
PULLEY RUN-OUT
Axial pulley run out will influence alignment readings. Axial run
out should be confirmed to be within recommended limits.
