RoadXYZ,
thanks for the feedback!
All the AC motors I have seen use a porous copper alloy material for bushings, no bearings. They are not sealed, or are very poorly sealed. The bushing that is easily seen when removing the AC shroud seem to occasionally stick after sitting for a period of time (winter storage, etc). Once freed, the bushings seem to still last a long time. Shooting a little spray lube in there is a good thing, and easily penetrates where it is needed.
The inner bushing is very hard to get to, and requires removal of the inner fan wheel to access. These are not open to the outside environment, so they tend not to have a problem over the life of the motor.
