DIYbanter - View Single Post - Emerson-Pryne Exhaust Fan Motor

(pc macdonald) wrote in message om...
I've a vintage Emerson-Pryne exhaust fan in my mid 60's tract home
bath. The bearings are shot on the motor, and it looks like Emerson
sold off Pryne.

No model number. It is an early 60's vintage. Induction motor above
cross brace and below a 3 bladed aluminium fan around 6.6" in
diameter. Fits right into the duct.

Can't replace with conventional unit without ripping up upstairs
floor!

Suggestion for parts supplier?

tx

pc

Well, I found a new NuTone 686 in-duct unit with a 6.5" plastic fan at
Home Despot for about $28, essentially a modern, cheaper version of
the existing unit.

Aside from the plastic fan, the journal bearing assemblies were only
about 30% as tall as the bearings on the Emerson, and the shaft wasn't
anywhere near the 1/4" of the original. I was concerned that this one
wouldn't last anywhere near the 40 years of service the Emerson had
given...

So.... I marked the top bearing unit & completely disassembled the
fan motor. I soaked the bearing caps and armature in Ed's Red Bore
cleaner for about 10 minutes and cleaned them up with a stiff brush
(the solvent is about 1/3 each kerosene, ATF, acetone -- you can find
the formula in rec.guns). I carefully removed the fiber thrust
washers from the ends of the armature shaft, and LO! I found a
thinner thrust washer on each end, up against the armature, probably
metallic, that were in fragments. The thicker fiber thrust washers
facing the bearing caps were in OK shape.

I blew all the solvent out of the fiber lubricant carriers in the
bearing assemblies, and carefully inspected and cleaned the shaft and
armature ends to remove all debris. I had to pick out thrust washer
debris with a toothpick at the armature ends. There was lots of crap
burnt into the armature faces. The thrust end of the armature had
some annular groves in the face from the failed thrust washer, but
what the heck.

The lower journal bearing was showing thrust wear on the inner face,
so I interchanged the upper and lower assemblies and used a very thin
series aerospace grade 1/4" stainless washer as a spacer on the bottom
(thrust) side between the worn face of the armature and fiber washer
-- it was about twice as thick as the two worn out ones that were on
either end of the armature originally, so the total axial loosenes
(fit) was pretty close to original.

I put some 5W-30 motor oil on the shaft and reassembled. Voila! The
fan spins for about 15 or more seconds when the power is removed,
something it has never done since I've owned the home the last 20
years. It's lots quieter, and is pulling really hard.

Wifey gets to return the NuTone to Home Despot!