Hent Vibrationskompendiet her - Fredericia Maskinmesterskole
Hent Vibrationskompendiet her - Fredericia Maskinmesterskole
Hent Vibrationskompendiet her - Fredericia Maskinmesterskole
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Vibrationsmåling – vibrationsanalyse – balancering<br />
Indholdsfortegnelse:<br />
Teknikker og software til at forudsige rette vedligeholdsaktivitet ..................................................................................6<br />
Indledning ...................................................................................................................................................................6<br />
Gennemførelse af en plan for tilstandsbaseret vedligehold.............................................................................................6<br />
Indhold af målerapport mv..........................................................................................................................................7<br />
Eksempel 1: Sporing af lejeskade i en vekselstrømsmotor ved hjælp af vibrationsanalyse og elektrisk måling<br />
(spændingsmåling: aksel til jord) ....................................................................................................................................8<br />
Cost benefit analyse: .................................................................................................................................................10<br />
Eksempel 2: Deformation af en prægerulle på en papirkonverteringsmaskine.............................................................11<br />
Konklusion....................................................................................................................................................................12<br />
Vibrationer:.......................................................................................................................................................................13<br />
Hvorfra kommer vibrationer? .......................................................................................................................................13<br />
Vibrationsparametre:.....................................................................................................................................................14<br />
Acceleration, hastighed og forskydning....................................................................................................................14<br />
Accelerometer. ..................................................................................................................................................................14<br />
Det piezoelektriske accelerometer. ...............................................................................................................................14<br />
Accelerometrets opbygning. .........................................................................................................................................15<br />
Accelerometertyper.......................................................................................................................................................16<br />
Accelerometerets karakteristika. ...................................................................................................................................17<br />
Accelerometrets frekvansområde..................................................................................................................................18<br />
Måleteknik: .......................................................................................................................................................................19<br />
Valg af målepunkt for accelerometret...........................................................................................................................19<br />
Montering af accelerometret. ........................................................................................................................................20<br />
Miljøpåvirkninger. ........................................................................................................................................................22<br />
Generelt.....................................................................................................................................................................22<br />
Temperatur....................................................................................................................................................................23<br />
Kabelstøj. ......................................................................................................................................................................23<br />
Andre miljøpåvirkninger...............................................................................................................................................24<br />
Accelerometer kalibrering.............................................................................................................................................26<br />
Andre transducere. ........................................................................................................................................................27<br />
Grundlæggende teori.........................................................................................................................................................28<br />
Grundlæggende vibrationsteori.................................................................................................................................29<br />
Spids-, gennemsnits- og effektivværdier.......................................................................................................................32<br />
Almindeligt forekommende maskinfejl. ...........................................................................................................................35<br />
Ubalance. ......................................................................................................................................................................35<br />
Ubalance i maskiner med lodret akse........................................................................................................................36<br />
Ubalance i maskiner med overhængende leje ...........................................................................................................37<br />
Årsager til ubalance ..................................................................................................................................................37<br />
Graden af Ubalance...................................................................................................................................................37<br />
Opretningsfejl ...............................................................................................................................................................39<br />
Opretningsfejl............................................................................................................................................................39<br />
Vinkelfejl ..................................................................................................................................................................39<br />
Parallelfejl.................................................................................................................................................................39<br />
Almindelig opretningsfejl .........................................................................................................................................40<br />
Temperaturindvirkning på opretningen.....................................................................................................................40<br />
Fejlopretningens Vibrationsspektrum .......................................................................................................................40<br />
Årsager til opretningsfejl...........................................................................................................................................41<br />
Bøjet aksel.....................................................................................................................................................................42<br />
Symptomer................................................................................................................................................................42<br />
Roterende løsgang.....................................................................................................................................................43<br />
Stationær løsgang......................................................................................................................................................45<br />
Rulningslejer.................................................................................................................................................................45<br />
Non-synkrone toner...................................................................................................................................................46<br />
Typisk udvikling af lejeslid.......................................................................................................................................47<br />
Løsgang i rullekontaktlejer .......................................................................................................................................52<br />
Skæve rullekontaktlejer.............................................................................................................................................52<br />
Lejeproblemer i maskiner med flere aksler...............................................................................................................52<br />
Glidelejeproblemer........................................................................................................................................................53<br />
Typer af glidelejeproblemer......................................................................................................................................53<br />
Oliehvirvel ................................................................................................................................................................53<br />
Side 3 af 157