Contributor: Stan Riddle
In these days of AI, electronics, and smart devices, the “good old fashioned” visual inspection may seem dated. But there is no computer-aided device that can take the place of a skilled set of eyes inspecting a machine.
During a recent precision maintenance training class we taught, we were asked to go out to one of our customer’s pump rooms. They had experienced several pump failures and wanted to practice on some real machinery.
On one of the pumps we locked out, we removed the coupling guard, and saw this (picture above). I asked the group (mainly composed of young, inexperienced maintenance personnel) “What do you see?”
After a couple moments of silence, it was obvious that they weren’t sure what to look for. So I said “here’s what an old mechanic sees”: an elastomeric coupling insert that’s only being half used. The coupling hub separation was too far apart, so only half of the jaws are being used to transfer power.
The motor-side key appears much longer than it should be. Excessive vibration was measured on the motor drive end bearing, which is indicative of imbalance. This key could be the cause.
After this, the techs started looking around, and found a dry-rotting flexible inlet connector, a leaking mechanical seal, and a broken motor hold-down bolt. And the group started making repairs.
Hi-tech tools can diagnose many things, but they should be used in conjunction with a “low tech-high experience” visual inspection.