A manufacturing plant located in WA recently encountered a significant issue related to a critical drum drive gearbox. The Asset Management and Reliability Team noticed excessive vibrations and sought to identify the root cause of this problem. To address this issue, the Iris M™ Motion Amplification®® technology was utilised. This case study outlines how Motion Amplification®® technology successfully captured, quantified, and qualified the operational vibration characteristics and identified the root cause of the problem.

Problem Identification:

The manufacturing plant initially detected unacceptable levels of vibration in the drum drive gearbox of their machinery, which they had yet to identify. This vibration had the potential to disrupt operations and, if left unaddressed, could lead to costly equipment damage.

Motion Amplification® Analysis:

Upon implementing Iris M™ Motion Amplification®® technology, the plant’s Asset Management and Reliability Team conducted real-time data analysis, revealing several crucial findings:

1. Vibration Frequencies: The analysis showed that the majority of the vibration in the drum drive train occurred at three distinct frequencies:
   • Motor running speed: 25.76Hz
   • Pinion gearmesh frequency: 7.69Hz
   • 2x pinion gearmesh frequency: 15.38Hz

The presence of the 2x pinion gearmesh frequency indicated a classic symptom of gear misalignment and uneven wear across the gear teeth.

1. Phase Difference: There was a noticeable phase difference between the motor and gearbox input, which is a typical indicator of offset misalignment across the coupling.
2. Vertical Orientation: The vibration analysis also revealed that the vertical orientation of the inner side of the drum drive gearbox’s base frame exhibited higher levels of vibration compared to the outer side.

Recommendations:

Based on the observations and analysis using the Motion Amplification®® technology, the following recommendations were made to address the identified issues:

1. Pinion Inspection and Realignment: Given the presence of gear misalignment and uneven wear across the gear teeth, it was recommended that the pinion be inspected thoroughly. Any misalignment should be corrected and worn gear components should be replaced.
2. Torque Arm Connection Inspection: The connection between the torque arm and the base frame should be inspected for any signs of damage or misalignment. Any issues found in this area should be promptly addressed.
3. Motor-to-Gearbox Realignment: To resolve the phase difference identified between the motor and gearbox input, realignment of the motor to the gearbox is necessary. Proper alignment will ensure that power is transmitted efficiently and reduce unnecessary stress on the machinery.

The implementation of Iris M™ Motion Amplification®® technology proved to be instrumental in diagnosing and identifying the root causes of unacceptable vibrations in the drum drive gearbox. Through this analysis the plant was able to mitigate the vibration complications and prevent potential equipment damage, ensuring the continued smooth operation of their machinery.