Loose cardan joint caught the same day SAM4 was installed

Read how SAM4 caught a loose cardan shaft coupling within hours of installation on this long-term steel customer's runout table roll.

Thanks to two and a half years of monitoring runout table rollers at this customer’s hot strip mill, SAM4 was able to diagnose a loose cardan coupling in a new roll within hours of installation.

The customer installed SAM4 on a new roll. Because the roll and its motor were identical to other rolls SAM4 has been monitoring for years, SAM4 had a solid pool of comparable baseline data in its “fingerprints of failure” library. So when the first measurements for the new roll came in with high values for both the noise floor around the supply frequency and the roll’s rotational frequency—clear indicators for a loose coupling in this customer’s similar rolls—SAM4 instantly flagged the asset for inspection. Two days later the customer confirmed that the cardan joint was loose and replaced it.

“SAM4 is proven technology creating clear value for our business. And that value just goes up the longer we use it.”

Values over time for SAM4's first current interharmonic indicator, for three different rolls in this customer's runout table. The new roll is in purple. The yellow arrows indicate previous loose coupling detections in the two other rolls. You can see that three of SAM4's early measurements on the new roll came in at values higher than is normal on similar rolls. Usually SAM4 would need to learn the asset's normal behavior during a 4-week training phase, but thanks to 2.5 years of data from similar assets, we were able to immediately diagnose an existing problem. The customer confirmed the diagnosis and replaced the new roll's cardan joint at the black arrow.