The Fan . . .

We are going through a really hot spell here in East Texas.  Always on the edge of a semi arid climate we depend on irrigation wells to keep our lawns green and air conditioning to stay cool.  But in the garage where I spend some time there is not air conditioned, just a fan or two.

A few years ago, well maybe more than a few years, I bought a killer floor fan.  It is a high velocity fan about 15 or 16 inches in diameter.  It could move a lot of air and I positioned it near the door so it could suck in the cooler air and cool of the garage.  It did a very creditable job but then age caught up with it.

When starting up it would squawk and squeal like it had a bad bearing.  But it would run.  Then it started just stopping and maybe restarting later when it cooled off.  I took the switch assembly apart but all the parts were okay and there was no burnt or charred items so I knew it was functioning like it should.  So I figured the bearings had gone bad.

So while considering getting a new fan and tossing this one I decided to take it apart.  I took the blade guard off and was able to the three blade fan off of the shaft.  Not problem, it was held in place by a set screw and that was easy to get off.

The I attacked the fan motor case.  It had a series of nuts and bolts around it that held the two part case and the rear fan guard in place.  That was easy enough.  But splitting the case was a bit more of a challenge.  I was able to get it about a quarter of an inch apart, not near enough to do anything.  I did not want to break or bend the case just in case I could really fix it.

After a bit of working it back and forth I got the front case off, or at least the front half of the case off.  The outer electrical winding was firmly held in place by the rear half of the case.  I found both the front and rear of the rotor held in place by a simple sleeve type bearings.  I got the rotor off and it was in good shape.  And the motor did not have brushes so that was not the problem.

I got the rotor out of the rear mount, not a ball bearing but a sleeve bearing was used in the front and rear to support the rotor.  I thought maybe the shaft was galled up or the like and that was not the case.  I got the rotor out and the shaft was just fine.  I looked and in the rear bearing support I saw a piece of thin rear thrust washer.  It had broken into two parts.  I was able to fish out the bigger piece and I discarded that altogether.  I figure since the fan is constantly pulling forward a rear thrust washer was of no importance.  That is the shaft will be always pulling forward and thus it was just really a thin spacer.

I got my tube of trusty silicon grease that I have had for years and with a screw driver took a dab and place it in the rear support housing.  Since there was not galling and apparently what grease was in there had long ago disappeared, this new stuff would work for me.  I then place a dab of the grease in the front sleeve bearing.   I smeared a little on both ends of the shaft.  I noted that there were two or three front thrust washers and left them alone.  That tube was acquired about 20 years ago to use on a dot matrix printer shaft for lubrication.  I have used the grease on my models, etc.  However, I got that tube of grease from Radio Shak which is not longer in existence.

I reassembled the rotor shaft and fan motor housing to the rear fan guard.  I then replaced the fan blades and put the front fan blade guard back in place.  Got it all screwed back together, guard in place and plug in the power.  Then I turn it on.  wha-la, the started right up and ran at its old top speed again.  I had saved the cost of a new fan and this would continue to run for a while yet.

Sometimes it is worth while to take things apart and see if you can fix them.