[TheForge] OT - Grease/oil seals for a gear box

[Larry Brown]

Bruce
I would consider a slinger plate inside next to a sealed high speed 
bearing. The slinger would keep most of the oil off the bearing and the 
seal should hold the rest
Larry

At 11:33 PM 7/9/2009 -0500, you wrote:
>Bruce Freeman wrote:
> > Well, I am surprised!  I always thought of packing seals for plumbing
> > applications like valve stems, where the rotating rate is about once
> > per day!  I've looked up a little and find some of them are good for
> > "high speed" applications, but I don't have enough info yet to
> > determine what RPM that means.
> >
> > Does anyone know what considerations go into selecting design criteria
> > and packing material for an application with speeds upwards of 2000
> > RPM?  (I'm shooting for 10kRPM, but doubt I'll get there with this
> > prototype, for reasons other than the packing seals.)
>
>snip
>
>What I gotta say is wow. 10000 rpm is a lot for a seal. I tend to think
>that the only type of seal that will withstand that speed is a ceramic seal
>see:
>http://www.pumpseals.net/Outboard_seals.htm
>for a look see.
>The ceramic seals operate well at high speeds but the majority of
>installations that I have seen them in are for pumping water... they are
>therefor cooled by the water.
>
>If you can restructure the shaft and housing to accommodate a sealed
>high speed bearing such as those found in an automotive alternator you
>would be well served. The poor alternator operates at high rpm ( its
>usually 'geared' up at least 2:1 and some times 3:1, if the crank is
>turning 4000 rpm you can see what that does to the alternator shaft
>speed). Those bearings are pre lubricated and shielded.
>As a testament to their toughness the six bearings in my three cars,
>100050 miles, 150000 mi and 132000 miles are all original. if you can
>adapt your shaft and housing sizes that's the way I'd go...
>Good luck
>
>--
>Paul Sperbeck  WB9HCO
>
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