Benefits of shaft alignment
Benefits of shaft alignment
What is the problem?
Misalignment generates forces in the coupling between the machines
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.
Misalignment
Misalignment - when the two shafts are not collinear.
Types of misalignment Offset misalignment
Angular misalignment
Measuring Misalignment Viewed from the top - Horizontal Misalignment
Viewed from the side - Vertical Misalignment
Shaft alignment – basics Measure and adjust the machines so there
rotational centers are colinear
Shaft alignment - basics One of the machines is a reference–
Stationary machine
Shaft alignment - basics The second machine is adjusted
Moveable machine
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.
Alignment tolerances
Alignment Methods With all alignment methods measurements
are taken at the shafts or couplings.
Alignment Methods Misalignment is corrected at the feet.
Alignment Methods
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.
Dial indicator methods
Rim-Face method
Reversed-Rim method
Rim- Face Alignment method
The rim dial measures offset
The face dial measures angularity
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.
Misalignmet – the biggest single cause to high vibration levels
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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Fixturlaser product range
Shaft alignment
Alignment of belt drives Geometrical measurements
Benefits of shaft alignmentFixturlaser product rangeWhat is the problem?Rotational centersMisalignmentTypes of misalignmentMeasuring MisalignmentShaft alignment – basicsShaft alignment - basicsShaft alignment - basicsShaft alignment - basicsShaft alignment - basicsAlignment tolerancesAlignment MethodsAlignment MethodsAlignment MethodsMechanical methodsDial indicator methodsRim- Face Alignment methodReversed- Rim alignment methodLaser systemsMisalignmet – the biggest single cause to high vibration levelsMisalignment – is it common?Shaft alignment – it is important!VibrationsEnergy savingsWear of componentsWear of componentsProduction capacityProduct quality