PATTERN ANALYSIS ON THE DIFFERENCES OF SOUND ORIGINATED FROM MOTOR, GEARBOX, AND DISC BRAKE BASED ON SPECTOGRAMS

• Main Author: OKTAVIAN DWI CAHYO (NIM : 131 06 152); Pembimbing : Dr. Ir. Zainal Abidin, ANDI
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/14875
• Institution: Institut Teknologi Bandung

Rotating machine components such as motor AC, gearbox, and disc brake will produce sound patterns that vary during operation. The difference in sound is thought to have links with different characteristics of the vibration generated by the elements in the rotating machine components. Therefore, a research has to be conducted in this final year project to investigate the different patterns of sound and its relationship with the vibrations that come from motor AC, gearbox, and disc brake. In this study, an analysis on different patterns of sound was conducted based on three classifications that is, due to the different sound sources, due to rotational speed variations in the output shaft, and due to the use of lubricating oil in the gearbox. Furthermore, an analysis on the relationship between sound and vibration signals was also carried out by comparing the measurement results obtained from the three aforementioned components. All these analysis was carried out in the domain of time, spectrogram, and linear spectrum. Results obtained from this study shows that there are significant differences in the frequency content of the sound that comes from the three components of rotation. Sound produced in the motor is dominated by the sideband frequency component whose value approximately equals to four times the rotating frequency of the motor. While at the gearbox, there is a frequency component of the impulse signal that occurs repeatedly within a period that is approximately equal to the period of one motor rotation. And sound in the disc brakes contains frequency of friction signal that occurs over and over within a period that roughly equals to the period of one rotation of disc brake. The other side of these results also shows that there is a close connection between sound and vibration produced in the motor, although it’s difficult to find the same connection in the gearbox and disc brake.