Acoustic emission based condition monitoring study of piston rod seals by varying speed and pressure parameters
Peer reviewed, Journal article
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Original versionProceedings of the Annual Conference of the Prognostics and Health Management Society, PHM. 2020, 12 (1), 1-9.
Seal wear is one of the primitive causes of failure in hydraulic cylinders. Regular visual inspection of seals without affecting the productivity is difficult as the seals are placed internally in the hydraulic cylinder requiring disassembly of the piston. Therefore, condition monitoring is required to assess the current health of the seals. There have been successful attempts made in literature for the assessment of seal quality using acoustic emission-based condition monitoring. However, there have been very few acoustic emission-based condition monitoring studies performed to diagnose the seal failure under varying speed and pressure parameters. Therefore, this study aims at increasing the understanding of seal failure under varying speed and pressure conditions through correlation with the acoustic emission features. Experiments were performed on a hydraulic test rig using unworn and worn piston rod seals. For each seal wear condition, experiments were performed for five strokes at pressure conditions of 10, 20, 30 and 40 bar and piston rod speed of 50 mm/s and 100 mm/s. To reduce the noise from other machine parts in the test rig, the acoustic emission signal of each piston rod stroke was filtered using a bandpass filter. The acoustic emission signal before and after bandpass filtering was analyzed using different acoustic emission time and frequency domain features. For unworn and worn piston rod seal conditions, the acoustic emission features obtained from the acoustic emission signal after bandpass filtering have good separability and low variability when compared to the acoustic emission features obtained from the non-filtered data. Therefore, the acoustic emission-based condition monitoring methodology developed in this study lays a strong foundation for further research to develop real-time monitoring of the piston rod seal in hydraulic cylinders.