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Re: [TowerTalk] Re: Thrust bearing

To: <towertalk@contesting.com>
Subject: Re: [TowerTalk] Re: Thrust bearing
From: "Chuck Lewis" <clewis@knology.net>
Date: Thu, 22 Jul 2004 11:29:34 -0500
List-post: <mailto:towertalk@contesting.com>
About thrust bearing alignment...

I also belong to the "let the rotor bear the axial load up to its rated
limit" camp. Therefore, since the weight of my array plus mast falls within
the rotor spec, my "thrust" bearing exists only to react out the lateral
loads. For a simple, single thrust bearing situation like mine, the
alignment problem is avoided by leaving a small clearance between the three
radial bolts and the mast. Snug them up, back them off a fraction of a turn
and tighten the jam nuts. Then make sure the collar can rotate around the
mast without binding. It's probably a good idea to check this at several
azimuthal points, in order to assure that the worst-case misalignment still
allows freedom for the collar to rotate. I check the collar periodically to
verify that it still spins freely and with minimal clearance. The 'slop' at
the collar is so small that lateral movement of the mast is negligible, yet
the bearing provides a low-friction point to resist the overturning moment
of the mast while allowing the weight of the system to properly pre-load the
bearing races in the rotor.  More complex arrays will require more complex
solutions, but this works for me. YMMV!

Chuck, N4NM

----- Original Message ----- 
From: <john.brewer@us.schneider-electric.com>
To: <towertalk@contesting.com>
Sent: Monday, July 19, 2004 2:06 PM
Subject: [TowerTalk] Re: Thrust bearing


>
> >I don't know if there is a "definitive" answer, but just think about the
physics
> >of the matter. The rotor is equipped (if it is a heavy-duty type) with
multiple
> >races containing up to a hundred or more ball bearings. (The Hy-Gain
TailTwister
> >has three races with 138 bearings.) Is the thrust bearing this
well-equipped?
>
> Excellent point.
>
> Then there's the practical issue of how to align a thrust bearing with the
rotor,
> so as to not cause MORE binding than doing without would create...
>
> John K5MO



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