3.1 introducción
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BALANCEO DE
MÁQUINAS
INTRODUCCIÓN
BENEFICIOS DE LA ALINEACIÓN DE PRECISIÓN
- La vida de los rodamientos se incrementa en un factor de 8 veces.
- El ahorro en el Presupuesto de Mantenimiento es de 7%
- La disponibilidad de la maquina incrementa en un 12%
- Los paros imprevistos debido a la desalineación se reducen a la mitad.
- El ahorro de energía se estima en un 11%
BENEFICIOS DEL BALANCEO DE PRECISION
La tolerancia típica de los fabricantes de máquinas en el balanceo es de 5 @ 7,6 mm/s de vibración.
Se recomienda que la tolerancia para el balanceo sean la dadas por las normas internacionales ISO, API, VDI.
Efectuar balanceos de precisión cuando se repare una máquina.
Balanceo de precisión cuando la máquina sea nueva y antes de iniciar su servicio.
El balanceo de precisión incrementa de manera significativa la vida de los sellos y rodamientos.
La vida de los rodamientos se duplica.
Machine vibrations: unbalance vibration
1 2 3 4
Fdynamic
Fstatic
Fresultierend
r
munbalance
mrotor
Fstatic = mrotor gFdynamic = munbalance v ²
1 period per revolutionunbalance vibration with 1 fn
„ swinging “ load zone
Fres
t
1
Fstat
4 2
3
4
Fdyn vrms
Fres4 Fres1 Fres2 Fres3 Fres4
1
23
4
load zone
Fdyn
FstatFres1
Fdyn
Fstat Fres2
Fdyn
Fstat
Fres3
Fdyn
FstatFres4
Measurement locations show vibration causes (1)
1. Impeller unbalance
1a)Outboard overhung rotor
1b) Integrated drive direct drive
Measurement locations show vibration causes (1)
1. Impeller unbalance
Measurement locations show vibration causes (1)
1c)Belt drive
1. Impeller unbalance
Measurement locations show vibration causes (1)
1. Impeller unbalance
1d)Inboard rotor
Measurement locations show vibration causes (1)
2. Coupling unbalance, eccentricity in coupling
- coupling - unbalanced, one side or both sides, not half key balanced-wear in coupling -look up coupling
Measurement locations show vibration causes (1)
3. Misalignment
Offset
Measurement locations show vibration causes (1)
Angularity
3. Misalignment
Measurement locations show damage causes (2)
4. Foundation resonance
Measurement locations show damage causes (2)
5. Dependence on direction according to foundation stiffness
Rigid foundation
Measurement locations show damage causes (2)
5. Dependence on direction according to foundation stiffness
Flexible foundation
Eliminate causes before balancing
2Unbalanced couplingAfter remountingBalance coupling with half feather key
3Unbalanced belt diskAfter remountingCheck smooth run and seat, rebalance if required
1Dust in mediumRemove caked dust from rotor disk
5Dust in mediumWear and tear of blades in rotor disk; re-armour radial disk, exchange axial blades
4bOne-off thermal deformationDue to process temperature ( exceeded ? ) during installation or damage due to heat/coldCheck process control
6Blade tearsUsually on radial disksReplacement or rewelding by manufacturer
7Missing correction massesPoor welding, missing screwsReplace, secure well
8Warped rotor disk seatFollowing transport damagesRework, replace
Loose and scewed hub seatAfter mounting, loosen radial disk or screws.During operation, caution when using Taper lock or braced adapted sleevesRemount properly
9
10Incorrect axial blade assemblyDiametrically opposing blades should have equal masses and tilting momentsRemount blades properly
1 2
3
457
6
8
11Improper paint jobPaint coat thickness not uniformBalance
12Deformation due to centrifugal forceOverspeed - permanently deformedUnstable impeller - snaps due to warpinge.g. radial impeller blades are fixed and temporaly warpedExchange rotorRework impeller construction
4aTemporary thermal deformationDue to process temperature ( exceeded ? )Check process controlRotor disk construction 12
Balancing condition: a quality process
Narrow tolerances in sheet metal or cast thickness
Take into account welding order of blades
Optimize welding equipment and procedure to minimize warping
Optimize casting procedure to minimize warping and tolerances
Balance according to ISOConcentric run according to drawingAxial play according to drawingSufficient balancing speedBlades: re-turn outer radiusDifference in fit: balancing shaft/shaftimpeller seat - impeller hub tolerancesNon-uniform paint coat thickness
Construction
Define appropriate fits
Define appropriate tolerances
Construct for balancing in manufacturing, assembling maintaining anti-cake impeller types
Protection against wear and tear
Production technology Rotor productionManufacturer
Assembly
Proper assembly: impeller seatCorrect position: bore reference circles, rotor disk seat, especially for withdrawal sleevesField balancing with operation condition (warm), for large blowers after assembly or if components exchange
System installation/Repair Operation
Warping after high temperature or rapid temperature changeCaking of dustMaterial wear and tearUnstable impeller typeMaterial inclusions in hub body ( axial impeller)
Service and maintenance
Cleaning intervals after soilingMonitor wear and tear, exchange disk if nec.Balancing after component exchangeRepair of rotor according to manufacturer specificationsLoose base screws / foundation tearsBearing damage, bearing fault
Repair
30April
Operator
Balancing condition: a quality process
1. Construction
Define appropriate fits
Define appropriate tolerances
Construct for balancing in manufacturing, assembling maintaining anti-cake impeller types
Protection against wear and tear
Balancing condition: a quality process
Production technology Rotor productionManufacturer
Narrow tolerances in sheet metal or cast thickness
Take into account welding order of blades
Optimize welding equipment and procedure to minimize warping
Optimize casting procedure to minimize warping and tolerances
Balance according to ISOConcentric run according to drawingAxial play according to drawingSufficient balancing speedBlades: re-turn outer radiusDifference in fit: balancing shaft/shaftimpeller seat - impeller hub tolerancesNon-uniform paint coat thickness
Balancing condition: a quality process
Assembly
Proper assembly: impeller seatCorrect position: bore reference circles, rotor disk seat, especially for withdrawal sleevesField balancing with operation condition (warm), for large blowers after assembly or if components exchange
System installation/Repair
Balancing condition: a quality process
Operation
Warping after high temperature or rapid temperature changeCaking of dustMaterial wear and tearUnstable impeller typeMaterial inclusions in hub body ( axial impeller)
Service and maintenance
Cleaning intervals after soilingMonitor wear and tear, exchange disk if nec.Balancing after component exchangeRepair of rotor according to manufacturer specificationsLoose base screws / foundation tearsBearing damage, bearing fault
Repair
30
April
Operator
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