Belt Installation Tension; Tips On Using The Sonic Tension Meter - Gates 550C Manuel D'utilisation

550C
GATES SONIC TENSION METER MANUAL

5. BELT INSTALLATION TENSION

Proper belt installation tension is essential in V-belt,
Micro-V and synchronous drives for optimum
®
performance and reliability. The correct installation
tension for a belt, or set of belts, depends upon the
drive geometry and load conditions and must be
calculated. Procedures for calculating belt tension are
included in the appropriate drive design manual or
software. To determine the belt tension recommended
for specific drive applications, either refer to the
appropriate drive design software DesignFlex
(available for download on https://www.gates.com/
gb/en/knowledge-centre/engineering-applications.
html), or contact Gates Application Engineering.
6. TIPS ON USING THE SONIC
TENSION METER
Gates' Sonic tension meter is capable of measuring
belt tension with greater accuracy and consistency
than traditional methods. It should not, however,
be expected to produce exact results in every case.
Numerous factors can influence the accuracy of the
meter's output, one must remember that traditional
methods of belt tensioning such as force/deflection
or belt elongation are approximate.
The following suggestions are provided to help you
achieve a high level of accuracy with Gates Sonic
tension meter.
After you have entered the correct numbers into
ƒ
the meter, take at least three readings to confirm
that results are consistent and that the meter
is not erroneously reading background noise.
When measuring the tension in synchronous belts,
ƒ
use spans that are more than 20 times longer than
the tooth pitch. Using spans shorter than this may
result in readings that are higher than the actual
tension due to belt cross-sectional stiffness.
When measuring the tension in V-belts, use
ƒ
spans that are more than 30 times the belt top
width. Using spans shorter than this may result
in readings that are higher than the actual
tension due to belt crosssectional stiffness.
There are limits as to how low a span tension
ƒ
value can be measured depending upon the belt
type and cross-section. Minimum recommended
installation tension values are available for all
belt sections from either drive design software,
drive design manuals or Gates Application
GATES.COM
Engineering. Measuring tensions below these
minimum recommended values should be
avoided, as the meter may display "ERROR"/
"Error-Re-measure" or provide inaccurate results.
When measuring belt installation tension, turn
ƒ
the drive over by hand for several revolutions to
fully seat the belt and equalise tension in all of
the spans before making any measurements.
Factors such as pulley/shaft eccentricity, belt/
sheave groove variation, etc., can influence belt
tension as the pulley or sheaves rotate. If the
Pro
™ ™
measured belt tension changes significantly as
the drive is rotated, and accurate measurements
are needed, determine the low and high values
and average them together. When the tension of
2 spans differs more than 30% approx., adjust
them almost equally and measure again.
Wind can adversely affect the ability of
ƒ
the meter to make a reading by creating
excessive background noise. If measuring in
a windy location, shield the sensor from the
wind or use a microphone windscreen.
An optional inductive sensor should be utilised
ƒ
in noisy or windy environments for optimal
results. The inductive sensor uses a magnetic
field rather than sound waves. A simple way to
use this sensor is with a magnet taped to the
backside of the belt. Small "rare earth" magnets,
which are included in the Inductive sensor
package (Product No: 7420-00212) provide
excellent results with minimal influence on the
belt span frequency due to the added weight.
If a specific process is used to set belt tension in
ƒ
a particular application, and the meter is used
only to monitor the resulting belt tensions, the
frequency mode can be used rather than displaying
an absolute tension value. Belt span frequencies
for minimum and maximum tension conditions can
be measured so assemblers/technicians can use
the meter to verify that belt installation tension
is within an acceptable range. These frequency
values can also be found by using the DesignFlex
Pro belt drive design software (available for
™
download on https://www.gates.com/gb/en/
knowledge-centre/engineering-applications.html).
Tension measurements made on belts at very
ƒ
low tensions may yield greater variability and a
greater probability for errors. If a tension reading
cannot be obtained, the belt may be too loose
to generate a clear harmonic frequency signal.
If this is the case, the belt may need to be
tightened in order to obtain a tension reading.
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