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Misalignment Costs Time and Money
Shaft misalignment
Shaft misalignment is responsible for
up to 50% of all costs related to rotating machinery breakdowns.
These breakdowns increase unplanned machinery downtime, resulting in
higher maintenance costs and loss of production. Additionally,
misaligned shafts can increase vibration levels and friction, which
can significantly increase energy consumption and can cause
premature bearing failures.
Overheated motor due to misalignment
Photo made using a FLIR infrared camera
Traditional shaft alignment methods
Traditional alignment methods, although very common, do not often
produce the exacting degree of accuracy required by today's
precision machinery. The rough alignment methods still used
nowadays, such as using a straight edge and feeler gauge, may be
quick, but they can be inaccurate. Another traditional method
employing dial indicators offers a higher degree of accuracy, but it
requires specialist operators and can be time consuming.
Straight edge and feeler gauge method
Dial indicator method
Laser shaft alignment method
Laser alignment methods are a marked improvement on traditional
ones. A laser shaft alignment tool facilitates a quicker and more
accurate alignment than traditional methods. Since shaft
misalignment has a direct, negative, impact on bearing service life,
SKF offers a range of high precision, easy-to-use laser shaft
alignment tools. The tools, the TMEA Series, combine simplicity with
a high degree of accuracy. They feature a three-step process for
correcting alignment: Measuring, Aligning and Documenting.
Accurate shaft alignment can help you:
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Increase bearing life
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Reduce stress on couplings and
thereby the risk of overheating and breakage
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Reduce wear on seals, helping to
prevent contamination and lubricant leakage
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Reduce friction and thereby energy
consumption
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Reduce noise and vibration
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Increase machinery uptime,
efficiency and productivity
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Reduce costs of replacing
components and machinery downtime
Parallel misalignment (or offset)
Angular misalignment
Correct alignment
Belt misalignment
One of the common reasons for
unplanned downtime of beltdriven machinery is pulley misalignment.
Pulley misalignment can increase wear on pulleys and belts as well
as increasing the noise and vibration levels, which can result in
unplanned machinery downtime. Another side effect of increased
vibration is premature bearing failure. This too can cause unplanned
machinery downtime.
Measuring parallel and angular
misalignment using a straight edge or a piece of string
Traditional belt alignment methods
These methods, which are the most widely used, involve either using
visual judgement alone or visual judgement in combination with a
straight edge and/or length of string. The advantage of these
traditional methods is the perceived short time needed for
adjustment, although the use of a straight edge takes more time than
visual judgement alone. The major disadvantage is the lack of
accuracy. Some belt manufacturers recommend a maximum horizontal
angle misalignment of 0,5° or even 0,25°, which is impossible to
accomplish by using naked eye.
Correct alignment means that the
grooves of the pulleys are aligned
Laser belt alignment methods
A laser belt alignment tool facilitates alignment with far more
speed and accuracy than with traditional methods. Belt alignment
tools available on the market can be categorised according to the
way the tools can be attached to the pulley and the way they align.
In general there are two groups; one aligns the face of the pulleys
and the other aligns the grooves of the pulleys.
The major disadvantage of the tools,
which use the face or side of the pulley as a reference for aligning
the pulleys and belts, is that only the face of the pulley is used
as a reference.
This means that only the faces of the pulleys are aligned with each
other and not necessarily the grooves in which the belt runs.
This method results in varying degrees of accuracy when the pulleys
are of different thickness, brands or kinds.
The tools, which align the grooves of
the pulley allow for alignment where it counts most in the grooves
of the pulley, substantially increasing accuracy irrespective of the
thickness, brand or type of pulleys.
Accurate pulley and belt alignment can
help you:
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Increase bearing life
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Increase machinery uptime,
efficiency and productivity
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Reduce wear on pulleys and belts
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Reduce friction and thereby energy
consumption
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Reduce noise and vibration
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Reduce costs of replacing
components and machinery downtime
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Vertical angle
misalignment |
Horizontal angle
misalignment |
Parallel
misalignment |
Correct
alignment |
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