Deteksi Cacat Lintasan Luar Bantalan Bola pada Fan Industri Menggunakan Metode Cepstrum
DOI:
https://doi.org/10.18196/st.v23i1.9980Keywords:
Ball bearing, BPFO, cepstrum, fan, harmonicsAbstract
Bantalan bola pada sebuah fan (kipas) menerima beban dinamis yang sangat besar ketika beroperasi. Hal ini menyebabkan bantalan mengalami keausan yang harus dapat segera dideteksi untuk mencegah kerusakan/cacat lebih lanjut. Salah satu metode deteksi yang sering digunakan adalah metode analisis spektrum. Namun metode ini menghasilkan harmonik dan sidebands yang rumit jika diaplikasikan pada fan dengan transmisi roda gigi sehingga observasi amplitudo pada spektrum sulit dilakukan. Penelitian ini mengusulkan metode cepstrum ketimbang spektrum karena cepstrum dapat mengelompokkan berbagai harmonik yang berasal dari getaran komponen-komponen fan sehingga amplitudo cacat bantalan dapat diidentifikasi dengan mudah dan jelas. Bantalan yang digunakan dalam penelitian adalah tipe ASB 6209 2RS dengan kondisi normal (tanpa cacat) dan cacat lintasan luar. Cacat pada bantalan sengaja dibuat menggunakan Electrical Discharge Machine (EDM) dengan kawat kuningan berdiameter 0,25 mm. Hasil penelitian menunjukkan bahwa spektrum dapat mendeteksi frekuensi poros fan 9,11 Hz, frekuensi ball pass frequency outer (BPFO) 36,52 Hz, dan frekuensi poros roda gigi 22,59 Hz. Namun demikian amplitudo BPFO sulit diidentifikasi pada spektrum karena secara visual bercampur dengan amplitudo harmonik dari komponen-komponen lain yang turut bergetar pada fan. Hasil lebih baik diberikan oleh metode cepstrum dimana amplitudo quefrency BPFO sebesar 0,027 detik, yang bersesuaian dengan BPFO, sangat jelas terlihat karena tidak terganggu oleh amplitudo lain di sekitarnya.
A Ball bearing in a fan experience a very large dynamic load during its operation. This causes wear which must be detected immediately to prevent severe damage. One detection method that is often used is the spectrum analysis. However, this method produces complex harmonics and sidebands when applied to a fan with a gear transmission which makes it difficult to observe amplitude on the spectrum. This research proposes the cepstrum method rather than the spectrum because the cepstrum can classify the various harmonics that come from the vibrations of the fan components so that the amplitude of the bearing defects can be identified easily and clearly. The bearings used in the study are ASB 6209 2RS with normal condition (no fault) and with outer race fault. Defect in the bearings is intentionally made using an Electrical Discharge Machine (EDM) with 0,25 mm brass wire. The results show that the spectrum can detect the fan shaft frequency of 9,11 Hz, the ball pass frequency outer race (BPFO) 36,52 Hz, and the gear shaft frequency of 22,59 Hz. However, the BPFO amplitude is difficult to identify on the spectrum because it is visually mixed with the harmonic amplitude of the other vibrating components. A prominent results are given by the cepstrum method where the quefrency of 0,027 s, which corresponds to the BPFO, is clearly visible because it is not disturbed by other amplitudes.
References
Borghesani, P., Pennacchi, P., Randall, R. B., Sawalhi, N., & Ricci, R. (2013). Application of cepstrum pre-whitening for the diagnosis of bearing faults under variable speed conditions. Mechanical Systems and Signal Processing, 36(2), 370-384.
Gupta, P., & Pradhan, M. K. (2017). Fault detection analysis in rolling element bearing: A review. Materials Today: Proceedings, 4(2, Part A), 2085-2094.
Kamiel, B. P., Mulyani, M., & Sunardi, S. (2017). Deteksi Cacat Bantalan Bola Pada Pompa Sentrifugal Menggunakan Spektrum Getaran. Semesta Teknika, 20(2), 204-215.
Makhijani, R., Shrawankar, U., & Thakare, V. M. (2011). Speech Enhancement Using Pitch Detection Approach For Noisy Environment. International Journal of Engineering Science and Technology, 3(2), 1764-1769.
Morsy, M. E., & Achtenova, G. (2015). Envelope Detection and Cepstrum Analysis for Gear Fault Diagnosis - A Comparative Study. Paper presented at the Measurement, 10th International Conference, Smolenice, Slovakia.
Ning, C., & Jie, Z. (2007, 22-24 Aug. 2007). A Novel Echo Detection Scheme based on Autocorrelation of Power Cepstrum. Paper presented at the 2007 Second International Conference on Communications and Networking in China.
Peeters, C., Guillaume, P., & Helsen, J. (2017). A comparison of cepstral editing methods as signal pre-processing techniques for vibration-based bearing fault detection. Mechanical Systems and Signal Processing, 91, 354-381.
Randall, R. B., & Sawalhi, N. (2011). Use of The Cesptrum to Remove Selected Discrete Frequency Components From A Time Signal. In Rotating Machinery, Structural Health Monitoring, Shock and Vibration (Vol. 5, pp. 451-461). New York: Springer.
Vernekar, K., Kumar, H., & Gangadharan, K. V. (2014). Gear Fault Detection Using Vibration Analysis and Continuous Wavelet Transform. Procedia Materials Science, 5, 1846-1852.
Vernekar, K., Kumar, H., & Gangadharan, K. V. (2015). Fault Detection of Gear Using Spectrum and Cepstrum Analysis. Proc Indian National Science Acad, 81(5), 1177-1182.
Zhang, X., Hu, N., Hu, L., Fan, B., & Cheng, Z. (2012). Enhanced Fault Detection of Rolling Element Bearing Based on Cepstrum Editing and Stochastic Resonance. Journal of Physics: Conference Series, 364, 012029.
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