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Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany www .MMF.de
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Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Mar 26, 2015

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Page 1: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Machine Condition Monitoring

Introduction

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de

Page 2: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 2

Machine Vibration Monitoring

Predictive Maintenance:• Monitoring techniques include

vibration, acoustic noise, temperature, oil condition

• Helps to predict machine failure with sufficient accuracy to enable repair before breakdown

• Maintenance can be better planned• Increased plant availability• Reduced maintenance costs• Better product quality• Increased plant safety

Traditional Maintenance:• Periodic shutdown and overhaul

schedule• Production is stopped, off-line

machinery is inspected for wear and wear-prone components

• Bearings, fans, gear boxes and other parts are replaced, irrespective of their potential to operate for a longer time

• Between these scheduled repairs unpredicted plant breakdowns cause production loss

• Unscheduled repairs may be costly

Machine Maintenance

Page 3: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 3

Machine Vibration MonitoringAdvantages of Monitoring Vibration:

• Vibration magnitude is proportional to the magnitude of the problem• Vibration measurement is non-invasive• Most faults show increased vibration in an early stage of the deterioration sequence• Vibration can be measured instantaneously• Vibration can indicate severity and deterioration rate of a fault• Vibration can help to find the location of the fault• Vibration can help to find the cause of the fault

Page 4: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 4

Machine Vibration MonitoringHow Machine Vibration is Generated:

• Operating machinery produces vibration due to its rotational or linear motion• Increasing trends towards a higher level indicate emerging problems• Typical problems arise through

- misalignment of drive train components- worn or damaged bearings- load asymmetry due to debris adhesion on rotary parts like fans etc.- incorrect assembly

• Vibration generally occurs with its major component perpendicular to the rotational axis of the load transmission shaft

• The amount of vibration depends on - the stiffness and geometry of the machine's structure - the machine foundation - the speed of rotation of the shaft

Page 5: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 5

Machine Vibration Monitoring

Vibration Monitoring

Permanent Monitoring• Vibration switches• Vibration severity monitors• Spectrum monitors

Regular Patrol• Hand-Held vibration severity meters• FFT analyzers• Data loggers

VM12 VM15M12VS6

Page 6: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 6

Machine Vibration MonitoringVibration Severity Monitoring:• Widespread and simple method for vibration monitoring• Measurement of vibration velocity, also called vibration severity in mm/s• Vibration severity is a measure of energy of the emitted vibration• Frequency range: 10 to 1000 Hz

ISO 10816:• The standard gives recommendations for the evaluation of machine vibration by

measurements on non-rotating parts

Page 7: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 7

Machine Vibration MonitoringRecommendations for Sensor Locations to ISO 10816-1 :• Vibration measurements on machines should be made preferably at the housing of

bearings or nearby measuring points• For routine monitoring it is sufficient in many cases to measure vibration either in

vertical or in horizontal direction• Rigidly mounted machines with horizontal shafts have their highest vibration levels

mostly in a horizontal direction. • Flexibly mounted machines may have high vertical components of vibration, too • For inspections, vibration should be measured in all three directions (vertical,

horizontal and axial) at all bearings.

Page 8: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 8

Machine Vibration Monitoring• The following illustrations show some examples for suitable measuring points:

vertical

horizontalaxial

vertical

horizontalaxial

Page 9: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 9

Machine Vibration Monitoring

hor

izo

nta

l

axial

vertical

axialhorizontal

vertical

Page 10: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 10

Machine Vibration Monitoring

• Recommendations for measuring points at different types of machines can also be found in ISO 13373-1. horizontal

vertical 2

vertical 1

Page 11: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 11

Machine Vibration MonitoringVibration Severity Limits to ISO 10816-1:• If no reference values of vibration severity

are available on the relevant machine, the recommendations of ISO 10816-1 can be used

• Permissible values of the vibration severity are given for different machine types

• The basis of the assessment is the maximum value of all measured points on the machine

Page 12: Machine Condition Monitoring Introduction Metra Mess- und Frequenztechnik Radebeul / Germany .

Metra Mess- und Frequenztechnik Radebeul / Germany www.MMF.de 12

Machine Vibration MonitoringVibration Measurement on Reciprocating Engines to ISO 10816-6:• Reciprocating engines, like combustion engines and compressors, are characterized

by backward and forward going masses. • The vibration generated by this motion, is higher than the vibration of rotating

machinery. • ISO 10816-6 includes recommendations for the assessment of vibrations of

reciprocating machines. • The measured quantities are the RMS values of acceleration, velocity and

displacement. • They are measured at the machine block in all three axes of the room. The

recommended frequency range reaches from 2 Hz up to 1000 Hz. • By means of the measured values of all three vibration quantities, the reciprocating

engine may be classified as belonging to a particular class of assessment. • The following table allows this classification. At first read the relevant vibration

severity level for all three measured vibration quantities. The decisive class is the highest of these three determined severity classes. In the right part of the table you find the degree of machine condition in dependence on the machine class (depending on size, construction, assembly and speed of the machine).

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Machine Vibration Monitoring Vibration Measurement on Reciprocating Engines to ISO 10816-6:

A New machinesB Continuous running without restriction possibleC Not suitable for continuous running, reduced operability until the next scheduled maintenanceD Too high vibration, damage to the machine cannot be excluded