benefits of shaft alignment - laser alignment services, · pdf file ·...
TRANSCRIPT
Rotational centers
All shafts, whether they are straight or bent, rotate on an axis called the rotational center. The rotational center forms a straight line.
Measuring Misalignment Viewed from the top - Horizontal Misalignment
Viewed from the side - Vertical Misalignment
Shaft alignment - basics The alignment system measure the position of the
moveable machine according to the stationary
Shaft alignment - basics Adjustments are done on the moveable machine until the two rotational centers
are collinear.
Mechanical methods
Straight edge/feeler gauge method
Determine the direction and amount of offset using a straight edge and feeler
gauges.
Measure the gap at two points 180° apart to determine the direction and amount of
angular misalignment.
Reversed- Rim alignment method
• Widely acknowledged as the“preferred method” of shaftalignment.
• Both dials measure offset onthe Rim. The Angular error isthe slope between the twooffset values.
• Easy to plot or calculate thefeet correction values.
Laser Shaft Alignment Systems
Single laser systems with a single or double detectors.
Twin laser systems using the Reversed-Rim method.
Misalignment – is it common?
Studies has shown that up to 90% of all rotating machinery runs outside recommended alignment tolerances.
Shaft alignment – it is important!
• Key factor in successful condition based maintenance
• Misaligned machines are the single largest cause to high vibration levels.
• Cause failure in bearings, seals and couplings
• Will lead to machine breakage and increased down-time if not implemented
Vibrations
General and coarse analyse of vibration results: • Horizontal vibration indicates unbalance (H) • Vertical vibrations indicates a weak or loose
foundation(V) • Axial vibrations indicates misalignment (A)
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Energy savings
Correctly aligned machines can save up to 15% in energy consumption, sometimes more
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Wear of components
Bearings Increased load will mean an exponential decrease in lifetime on bearings. Example: double the load, reduce the lifetime to 1/8
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Wear of components
Seals
Misalignment can reduce lifetimes of mechanical seals with 50-70%. Leakage - a typical indication of misalignment
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Production capacity
• A modern production process is extremely depenent on availability.
• Cost for lost production is high, 10-100 kUSD/h
• The cost of a stop in production is normally a lot higher than cost for, be several times…
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Product quality
• Decreased vibration levels can directly give effect on product quality.
• Example: products with high level of surface treamment could be directly effected by misalignment.
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