EMU-train depots widely use the COMPACS®-EXPRESS vibration acoustic diagnostics systems, designed for condition evaluation of WMU of motor-driven rolling stock during scheduled maintenance and repair works.
The diagnostics is aimed at increasing reliability and resource of technical systems. The main diagnostic task is to evaluate the condition of units and assemblies and classify it as good or faulty. That is closely connected with the risk of false alarm or defect skipping. The present work is devoted to reliability increase of rotary units’ condition diagnostics with simultaneous decrease of complexity of its usage.
An analysis of geometrical parameters of a bearing assembly resulted in dependency of vibration level from rotation frequency and defect’s size. According to the dependency, the vibration signal amplitude rate is proportional to the bearing rotation frequency and the defect’s size. Using the COMPACS®-EXPRESS systems the dependency proved valid. A diagnostic error connected with false alarm or defect skipping probability can be eliminated by using an ambiguity area limited by the highest and the lowest critical values.
The paper considers the developed approach to reduce the diagnostic error by using an ambiguity area and conducting an additional independent testing. Thus, using an ambiguity area in condition evaluation together with two independent tests, increasing complexity of its usage not more than by 2, substantially increases the reliability of rotary units condition diagnostics.
Kostyukov Al.V., Kazarin D.V., Zaytsev A.V. Reliability increase of rotary units’ vibration analysis // XX Russian scientific conference on NDT and technical diagnostics: proceedings – Moscow: Spectr Editorial, 2014. – p.355-357. Download the publication
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