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thanks for your wisdom. when I think about it I realize that my "knowledge"
of bearings came from adjusting, or attempting to adjust, the cones on my
bicycle. Too tight and it was harder to pedal, too loose it was wobbly.
from there I went on to build airplanes and even offer rides!
Kevin Lane Portland, OR
e-mail-> n3773@comcast.net
web-> http://home.comcast.net/~n3773
(browse w/ internet explorer)
----- Original Message -----
From: <Lehanover@aol.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Wednesday, August 27, 2003 5:02 PM
Subject: [FlyRotary] Re: roller bearings
> In a message dated 8/27/2003 7:24:28 PM Eastern Daylight Time,
> n3773@comcast.net writes:
>
> > Tom Green of Vans tells me that the main gear roller bearings like to be
> > tight, that I could even run 4-6 in/lbs of torque on the nut. He says
they
> > are different from ball bearings. I have never heard such a thing and
> > wondered what is the general consensus on this. My outside bearing
races
> > have worn after 1000 hrs. I always tightened then and then backed the
nut
> > off one face before cottering.
> > Kevin Lane Portland, OR
> > e-mail-> n3773@comcast.net
> > web-> http://home.comcast.net/~n3773
> > (browse w/ internet explorer)
> >
> > That is correct. Tapered roller bearings can be damaged if run a bit
> loose. They have preload figures for each size. The race car bearings are
quite
> large, and I tighten them to 3 foot pounds. I have never had a bearing
failure.
> These bearings have a system that allows for any preload and a positive
lock
> using two lock nuts.
> You would always want the bearings loaded, so the wheel would track as
rigged.
>
> After servicing a bearing, I reinstall it and torque the adjusting nut to
20
> foot pounds.
> For smaller bearings, use less torque. This assures that the new races are
> seated firmly in their wells. Then I turn the hub over a few times. Then
loosen
> the adjusting nut until the bearing set shows obvious play. Then tighten
the
> adjusting to whatever torque for your specification.
>
> If the nut is not in a position to install a cotter, think about a shim
> washer between the adjusting nut and the "wear washer" between the nut and
the
> bearing race. Install a washer that will allow the correct torque and a
cotter
> installation. Only the hard "wear washer" against the inner race. The
inner
> races "walk" around the shaft all of the time. A thin shim washer will
wear away.
> The wear washer is usually pinned or keyed to the shaft, so it cannot
turn.
> Otherwise it would be trying to loosen the adjusting nut all of the time.
> Another trick, is to buy a collection of nuts. The threads will seldom
have
> identical starts, so one, or another will come out just right over the
cotter hole.
>
> Lynn E. Hanover
>
> >> Homepage: http://www.flyrotary.com/
> >> Archive: http://lancaironline.net/lists/flyrotary/List.html
>
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