Vibration Signals from Rotating and Reciprocating Machines: The Efficiency of Machine Condition Monitoring for Maintenance

Abstract

Machine conditionmonitoring is an important part of condition-based maintenance (CBM), which isbecoming recognized as the most efficient strategy for carrying out maintenancein a wide variety of industries. Machines were originally ‘run to break’, whichensured maximum operating time between shutdowns, but meant that breakdownswere occasionally catastrophic, with serious consequences for safety,production loss and repair cost. The first response was ‘preventivemaintenance’, where maintenance is carried out at intervals such that there isa very small likelihood of failure between repairs. However, these results inmuch greater use of spare parts, as well as more maintenance work thannecessary. As mentioned in most machine components give rise to specificvibration signals that characterize them and allow them to be separated fromothers, as well as distinguishing faulty from healthy condition. Thedistinguishing features may be because of different repetition frequencies, forexample a gear mesh frequency, which characterizes a particular pair of gears,and different sideband spacing’s which characterize the modulating effects ofthe two meshing gears on their common mesh frequency.