AF motor lifespan

[thebeardedgroundsman]

Has anyone any idea how long it takes for AF motors to wear out?

Obviously, so much depends on use, but it must be the most likely part of a lens to fail first.

[XKAES]

Electric motors do last a long time, but I'm no expert on WHY.  I have an solar-powered electric motor in my attic that is ON whenever the sun shines -- and it's still going strong after 30 years.  Never any maintenance.

Maybe there in an electrician in the FORUM that can explain it.