Moderators: Random Orbital Bob, nev, CHJ, Noel, Charley

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By nev
Evening all.
I'm part way through stripping an extractor motor for a bearing change but time ran out today so will continue tomorrow. Just to expedite matters and hopefully prevent any breakages does anyone have any experience with similar?
After half a gallon of 3in1 a bit of heat and a lot of patience I managed to remove the ally fan from the steel shaft and got to the front bearing which popped off without much persuasion so now on to the rear. I cannot see how the rear cooling fan is affixed to the commutator (?) shaft but looks like it could just be a push fit but seeing as its made of plastic and I'd rather keep it one piece does anyone have any idea how its assembled as there is no obvious bolt/thread/fixing as far as I can see, and the plastic fan I doubt would survive even a friendly puller.
The 'bolt' in the fan centre has no socket for a hex key or similar just a round dimple.

many thanks in advance
By Sideways
Had a similar experience when overhauling a Kity bandsaw and stripping the motor.
Look down this (long) post. You'll see some pics of a plastic fan and a splined shaft that it pushed onto.
A little corrosion on the splines made it hard to pull. Eventually I gave up and applied brute force - twisting overcame the splines that I didn't know were there - and I got lucky and the plastic was elastic enough that I didn't wreck it.

By Fitzroy
Assuming the fans just a push fit, after you removed it what would you expect to find? I’d guess you’d still need to separate the motor housing and bearing, does having the fan in place change how you would do that? I’m a ham fisted amature, but If I needed to replace the rear bearing I expect I’d end up trying to support the housing as close to the bearing as possible and drive the shaft through the fan and end motor housing in one go.

User avatar
By nev
I think the fan is the only thing stopping the casing from coming off the shaft and it looks as if the bearing has in/out movement within the casing, so will give it a tap tomorrow and see what happens.
By heimlaga
A strange animal that fan. Usually plastic fans have either a pair of holes or some slots to allow some sort of either standard or custom made gear puller to be used.

I have had apart maybe two dozen electric motors but never seen one like that.

I would put it in a hudraulic prass and slide some pieces of 3 mm saw blade steel (from a sash stawmill) under the fan for support. Then press down on the shaft.
User avatar
By nev
Thanks gents. Got back to it this afternoon and as Sideways suggested it was just a push on spline fitting holding the little fan on, a few taps with a suitable drift and it popped off.

Bearings are now off and replacements ordered. 8)

For any future finders of this post from the outside world the bearings are standard off the shelf jobbies - (NSK) 1x 6004RS and 1x 6201DU, about a tenner for the pair. Pleasantly surprised as the extractor unit in question, a Nederman Filtercart cost about 3k new :shock: