June 29, 2016
Low Cost Thermal Diagnoses Misalignment Machinery Health
By Tom Shelton
With the availability and decreasing prices of technology to help diagnose rotating machinery health, machine failure should be a diminishing concern. Thermal imaging cameras can be expensive; however, these cameras have very detailed diagnostic abilities and high resolution.
Reduced cost Thermal Imaging has recently become available through various sources. I recently purchased an infrared camera attachment for my smart phone through Amazon.com as I was curious if this would be a useful tool for the millwright/mechanic. There are several types available, many of which are sold on VibrAlign’s online store. You can browse the options here.
During a recent training class, I went on a thermal imaging walk-about looking for anomalies in their machines. I was pleasantly surprised to discover that they had been doing a great job of maintaining their rotating machinery! I’m not questioning the abilities of the mechanics or the maintenance management process of the plant, I just found it unusual to not find any severely misaligned machinery.
The thermal images from my smart phone below, show the highest and lowest temperatures in the electric motor frame when the photo was taken. As you can see from the images, the only heat in the machine is right where it should be… in the rotor/stator of the motor. Misalignment and improper lubrication are two of the typical failure causes that IR images will reveal, neither of which are indicated here. These are pictures of good health.
If misalignment were an issue the hot points would be at the couplings and inboard bearings. Let’s look at some images of “not so good” precision shaft alignments.
Notice the heat in the larger elements of the first image line. Also, misalignment is indicated by the heat shown in the couplings. That is wasted energy. As we know, heat is energy. Anytime we cause unnecessary friction this causes heat, therefore wasted energy and increased wear in the coupling and machine components. The end result is premature equipment failure.
Proper, indepth machine diagnosis using Thermal Imaging is an art in itself that can be learned over time. However, for the mechanic in the field, inexpensive alternatives are available for “quick and dirty” evaluation of machine health. Using lower cost thermal imaging and/or a good quality Infrared temperature gun are two useful and fairly economical options to see what the mechanic “needs to see.”
To browse some of these thermal imaging products, visit VibrAlign’s online store.