Early warning on failing cardan shaft coupling in runout table roller

Read how SAM4 caught a failing cardan shaft coupling in a runout table roll for this steel manufacturer.

Looseness caused by a fatigued cardan shaft coupling.

SAM4 flagged a sudden spike in the first current interharmonic at all the roller’s operating points. Several events with the same signature had been previously diagnosed on this and other rollers at this customer, so we were fairly certain we were looking at a failing coupling. We notified the customer and put the asset on red alert. One week later the customer performed maintenance, but the interharmonic values remained high. The customer explained that they hadn’t had time to replace the coupling during the planned window. Two days later they did replace it, and the roller’s electrical signature returned to normal.

“SAM4 has caught every failure in advance on these specific couplings, and never flagged one that wasn’t there. We view Samotics’ notifications as a trusted source and act accordingly.”

Values over time for the first current interharmonic indicator. Each color represents a different operating point. The graph shows a spike in intensity at all of them (red arrow). The two black arrows indicate previous coupling faults in this same roller, both of which SAM4 detected in advance of failure.

A heat map showing the intensity over time across the current frequency spectrum (blue is low, red is high). Time runs down the vertical axis from oldest to newest. The arrows mark the three coupling detections. All three show a clear rise in the noise floor (interharmonics).