Cost Effective Monitoring
Cost effective monitoring of journal bearing machines using Voyager Dynamics FDS with Waites predictive maintenance solution.
Many journal bearing machines are not adequately monitored due to the high cost of implementing proximity probes with a permanent rack monitoring solution. While expensive permanent rack monitoring solutions can be justified for high criticality turbomachinery and power turbines, they are not always practical for the motors, pumps, and fans operating throughout most industrial plants.
As a result, many facilities rely only on overall shaft displacement trends using their historian platform or attempt to monitor these assets using case-mounted accelerometers. Those approaches do not provide the plant with the diagnostic clarity needed to properly assess journal bearing machine mechanical integrity.
A more scalable and cost-effective alternative is to combine the FDS dynamic strain sensor with a Waites Wireless Node.
Key benefits:
- Journal bearing monitoring is comparable to proximity probes at a fraction of the implementation cost
- No shaft journal surface preparation required
- Simplified installation using adhesive-mounted FDS with the Waites wireless communication
- IEPE FDS sensors connect directly to a Waites Wireless Node using a short cable connection
- Battery-powered or line-powered deployment options
- Wireless communication from node to gateway eliminates expensive and labor-intensive cable runs
- High-frequency waveform and dynamic spectral data support advanced diagnostic capabilities of malfunctions and faults
- Continuous remote monitoring with cloud-based software allows analysts to view, analyze and report on data from anywhere
- Full diagnostic visibility at a cost point often associated only with basic overall vibration monitoring
Installation images below show single-sensor and dual-sensor FDS monitoring on a large AC induction motor. Learn more about the monitoring approaches: Voyager Dynamics.
Figure 1: Single FDS sensor on large motor used for basic diagnostics.
Figure 2: Two FDS sensors on large motor for full diagnostic capabilities.
Figure 3: Waites Wireless Node connected to FDS sensors for remote condition monitoring.
Figure 4. Overall trend, time waveform, and spectral data captured within the Waites platform using Voyager Dynamics FDS sensors in the Waites predictive maintenance software.
Figure 4 highlights several important observations from this installation.
- Since the sensor measures the dynamic reaction of the fluid pressure within the bearing rather than the journal surface, the FDS sensors do not require compensation typically associated with a proximity probe. Additionally, the data avoids the structural and mechanical noise commonly found in case-mounted accelerometer measurements, making the signals more straightforward to interpret and analyze.
- The data indicates a misalignment condition on the motor. In a properly aligned horizontal oriented motor, the maximum fluid pressure is typically expected near the bottom dead center (BDC) position of the bearing. For this reason, the primary FDS sensor is mounted at the BDC location to monitor pressure response. However, the trend data in figure 5 shows the FDS sensor located 45 degrees from BDC recording is higher in amplitude than the BDC reading. This suggests the pressure wedge has shifted from its expected location, which is commonly associated with misalignment. The spectral data further supports this, showing characteristic 1X, 2X, and 3X running speed harmonics.
This asset continues to be monitored through the Waites platform, and the customer has visibility into the developing condition to support planning during the next maintenance window.