[Mr Twister]

Its also used to remove the magnetic signature of Navy Ships. All the ships I was stationed on had a degaussing unit.

[chiphead]

It appears that bearing life is in reference to electric motor bearings. The magnetics of some types of electric motors can magnetize the bearings or the shaft. Metal debris is attracted to the magnetized bearing and starts causing damage inside the bearing or bushing the motor shaft rides on. Reliability of large motors is an entire field of study, primarily for factory reliability.

https://easa.com/resources/resource-...ing-failures-1

I did find one reference to demagging combustion engine parts. It appears that the concern is similar, metal debris sticks to bearing surfaces and cannot be easily wiped or blown off.

https://www.engineprofessional.com/TB/TB022318-1.pdf

[Shiny]

Originally Posted by chiphead

It appears that bearing life is in reference to electric motor bearings. The magnetics of some types of electric motors can magnetize the bearings or the shaft. Metal debris is attracted to the magnetized bearing and starts causing damage inside the bearing or bushing the motor shaft rides on. Reliability of large motors is an entire field of study, primarily for factory reliability.

https://easa.com/resources/resource-...ing-failures-1

I did find one reference to demagging combustion engine parts. It appears that the concern is similar, metal debris sticks to bearing surfaces and cannot be easily wiped or blown off.

https://www.engineprofessional.com/TB/TB022318-1.pdf

Thanks for this!

Never heard of magnetization leading to bearing erosion. Every industry has its own challenges I guess.

I once worked on a weird failure mode caused by static charge buildup in a high-rpm journal bearing. The static voltage would build high enough across the lubricant film to arc. The arcing affected nearby electronics but didn't destroy the bearings. The fix was to change the lubricant to one that dissipated the charge (more "conductive").

This residual magnetism effect sounds different... more like electrochemistry but is interesting to me!

[sdbob]

Thanks guys for clarifying this idea. The idea came from watching WW II Degaussing ships to reduce there magnetic signature to magnetic mines the Germans were dropping.

[rohrt]

Originally Posted by Mr Twister

Its also used to remove the magnetic signature of Navy Ships. All the ships I was stationed on had a degaussing unit.

My brother in law is a Navy man. We went an a party boat in Virginia and he pointed out this big structure for doing exactly that. He is a nuclear engineer but did some brief work with underwater mines. Its crazy how many there are.