Background
This case study highlights the early detection of motor bearing deterioration in a drive motor within an industrial environment, specifically at one of our global customers in Singapore. In an industry, where precision and efficiency are crucial, there is a recognized emphasis on maintaining demanding standards to optimize operations and minimize downtime. Therefore, in early 2019, the Eastway Safeguard® System was installed at this client company to ensure continuous 24/7 monitoring of both small and large equipment, including critical and non-critical assets.
Case description
In May 2022, an increase in both velocity (mm/s RMS) and acceleration (g’ RMS) was detected across the drive motor test points using the Eastway Safeguard® system. Refer to Figure 1 for the acceleration trend at the motor drive end and Figure 2 for the velocity trend at the motor non-drive end from January 2022 to October 2022. These figures illustrate a gradual increase intensifying over time.
Figure 1. Acceleration (g’ RMS) trend from motor drive end test point from January 2022 to October 2022
Figure 2. Velocity (mm/s RMS) trend from motor non-drive end test point from January 2022 to October 2022.
Analysis and Recommended Action
After detecting an increase in trends through the Eastway Safeguard® System, the Eastway remote monitoring team conducted an analysis of the motor’s vibration data. This analysis included examining vibration FFT spectra (Fast Fourier Transform) and time waveform signatures. The findings revealed various signs of early bearing deterioration, such as high peaks in the FFT spectra, noise, and non-synchronous frequencies.
Figure 3 shows a comparison of the acceleration FFT spectrum from January 2022 (blue front trend) to July 2022 (grey rear trend), highlighting the increasing frequencies associated with bearing deterioration.
Figure 3. Acceleration (g’ RMS) FFT waterfall spectrum comparison at the motor non-drive end test point from January 2022 (blue front trend) to July 2022 (grey rear trend).
Action Taken
Following Eastway’s recommendation, site maintenance personnel inspected the unit in November 2022 and found the motor bearings to be worn, with balls defect and visible damage to the outer race, see Figure 4. Consequently, the bearings were replaced. Figure 5 shows the acceleration (g’ RMS) trend, showing a significant reduction in vibration levels post-replacement. Additionally, Figure 6 provides a waterfall comparison of the acceleration (g’ RMS) FFT spectrum at the motor non-drive end test point before and after maintenance, highlighting the stabilization of frequencies related to bearing deterioration and confirming the effectiveness of the maintenance.
Figure 4. Worn motor bearings with balls defect and outer race damage.
Figure 5. Acceleration (g’ RMS) trend from motor drive end test point from July 2022 to December 2022 (post-maintenance)
Figure 6. Acceleration (g’ RMS) FFT waterfall spectrum comparison at the motor non-drive end test point from October 2022 (grey rear trend) and December 2022 (post-maintenance, blue front trend).
Results
The implementation of the Eastway Safeguard® System in 2022 resulted in savings of €39,000 by avoiding downtime and replacement costs. This includes 4 hours of maintenance time, typically involving gathering parts, locating and mobilizing personnel, and carrying out necessary repairs. By addressing the problem early and avoiding 3 hours of costly production downtime, estimated at €12,000 per hour, the system prevented €36,000 in potential downtime costs. Additionally, an estimated €3,000 in equipment costs was avoided by addressing the issue before it escalated. In total, the savings amounted to €39,000, demonstrating the financial and operational benefits of predictive maintenance in maintaining continuity and reducing costs (see Table 1).
Table 1. Estimated cost savings
