Tech Talk Blog

The life expectancy of filament wound composites like TriStar’s CJ product can be improved by understanding some of the typical failures. One consideration is the shaft material. In some applications where the motion is oscillating and at variable frequencies, the bearing can experience rapid wear. This is caused by small angle oscillation or small amplitude vibration and the resultant fretting corrosion. The wear debris that occurs can quickly become an abrasive that dramatically shortens life.

There are a couple of possible fixes for this problem. First, consider going to a 400 Series stainless pin. Testing by an independent company showed a 26 times improvement in wear life by making this simple change. The improvement was directly related to the elimination of the fretting corrosion that occurred on the 1215 carbon steel pin used before.

A second fix is improving the shaft finish and hardness. Another test showed that by going to a 50-55 Rc hardness on the shaft and improving the surface finish to 4-6 rms extended the wear life of an application from 500,000 cycles of life to over 1 million cycles.

One thing to look for if you are experiencing rapid wear of composite filament wound bearings is the debris. If the debris is a fine brown powder than the wear is normal. If the debris looks more like shavings or accumulates in large clumps on the shaft, then you may have a shaft material, surface finish or pin hardness issue that needs addressing.

That being said – CJ bearings are crucial for transportation and other roles. Find out more in our Shooting Star Archives!