I have a u2-1287 that runs smooth after a few
most electric fans have steel rotor shafts with bronze bearings.
they "call" them oilite bearings,susposedly because the bronze bushing (it is really a bronze bushing) but called a bearing, is oil impregnanted and susposed to be good for the life of the fan.
that is only true if you expect the life of the fan to be ONLY 18 to 24 months which is the average time that the factory oil lasts.
the oil dries up the longer the fan runs and the shaft makes the bronze bushing begin to heat up due to increased friction and eventually wear the round bronze bushinhg egg shaped.
Try giving your bearings a good healthy squirt of sae 30 wieght oil from a zoom spout-- [pull out straw squeeze bottle refillable oiler.]
I recommend oiling both the front and real fan motor bearings once a month.
This is the most common cause of fan failure.
Because I oil my fans bearings once a month,I still have fans that run from 1940,1950,1960 and 1970. The 1940 GE fan lasted 70 years and is still running strong.
Some newer fans have chinese ball bearings , but the ball bearings also die prematurely from lack of needed oil.
Sometimes, you can pry off the bearing race cover to get oil into the bearing.
a good trick here is to use wd40 if you think you cant get sae 30 into the bearing.
wd40 is a n extreemly light wieght oil that penetrates very well
and gets into places where you think it wont get into .
You can totally wet up a fan motor with either
sae 30 or wd 40 or both without worrying about the electric
motor being harmed by the oil.
the oil,sae 30 or wd 40 wont hurt the motor.
On badly rusted and nearly siezed fan motor bushings , or any electric motor as well, I use first wd40 for penetration and then sae 30 for good long duty lubricatin.
You may have to keep squirting ioil in the motor for 1/2 hour and end up with a puddle of oil under the fan motor, but about 40 % of the time ,you can bring back to life what yo thought was a dead motor. Perserverance is required and faith that you can fix the motor. 40 % of the time you get sucess to one degree or another and 60 % of the time ,its kaput for good.
I got all those fans i mentioned before because other people thought the bearing were seized and shot, and put the fans in the garbage pail where I rescued the fans from.
the bearings were almost siezed but far from shot becaue i got oil in to the shafts and bearings and another 12 to 20 years of life from the fans. However,i do oil them monthly in fan season, which is winter time for me, since I use fans to blow the hot air off my wood stove,
on Jan 20, 2015