Thanks to everyone for the help and suggestions! I was pretty convinced
that there should be some kind of rolling bearing assembly in the gap
between the bottom of the collar and the "seat" inside the receptacle at
the top of the tower. The "inner flange" of the collar sticks down exactly
0.250" into the receptacle and the seat in the receptacle is 0.450" deep,
so there is a 0.200" gap just waiting for SOMETHING to be sandwiched
between the two surfaces. Perhaps it was put there in anticipation of some
type of roller bearing assembly, or otherwise.
So, it sounds like this bearing is simply metal on metal, which seems odd
(is that really a "bearing"?), but upon further inspection I see that the
mating surfaces are not very sloppy (except that the face of the receptacle
has been worn a little), and that there is dirt resting on the "seat" of
the receptacle as if nothing has ever been in there (and no wear marks in
the horizontals surfaces where a roller bearing would go). I've rebuilt a
few engines in my day and I recall that the main bearings are
metal-on-metal (well, there is disposable piece of metal in BETWEEN the
crank and rod, which is the bearing), so I suppose this makes the
metal-on-metal scenario more plausible. Perhaps the types of metal
involved are of import. Curious.
In any event, this was my first post and I really appreciate the help, and
thanks to Steve for hosting the list. Now I have to let the previous owner
and her relatives know that I sent them on a wild goose chase.
Ken
KA6KEN
--On Saturday, May 15, 2021 9:59 PM -0700 "kj6y (null)" <kj6y@aol.com>
wrote:
That is the whole bearing. The collar sits on top of the plate. Use some
grease between the collar and plate.
Skip, KJ6Y
818-522-5421
Communications Service Co
Sent from my IPad
On May 15, 2021, at 7:56 AM, Ken Alker <ka6ken@alker.net> wrote:
Hi,
I recently acquired a Hy-Gain HG70HD tower. I hired a crane operator to
lift the mast/antenna assembly off the tower and then had the tower lifted
out of the back yard and placed horizontally on a boat trailer to haul it
away.
When I got home, I removed a "collar" from the mast that appears to be
what might sit on top of a thrust bearing (or, perhaps, *is* the "top" of
the thrust bearing assembly). Here is a picture:
http://www.alker.net/albums/ham-tower-thrust-bearing/IMG_6986.sized.jpg
This collar rested in a "female" circular mating piece that is bolted to a
plate on the very top of the tower. See following pictures:
http://www.alker.net/albums/ham-tower-thrust-bearing/IMG_6984.sized.jpg
http://www.alker.net/albums/ham-tower-thrust-bearing/IMG_6985.sized.jpg
I am assuming there was some kind of bearing "pack" sitting in between the
collar and the mating surface on the top of the tower that was stuck to the
bottom of the collar and fell off when the mast was lifted off the tower,
or it stuck to the mating surface on the top of the tower and fell off when
we tilted the tower over (or when I drove off).
That said, I'm not totally convinced there was ANY type of bearing between
these two items. Maybe they are meant to be lubricated and swivel against
each other? I don't think so, but I have no idea, as the manual I found
doesn't show any pictures of the optional thrust bearing assembly. There
is enough space between where the collar sits on the top of the tower, and
the inner "shelf" mating surface for some type of bearing assembly (I'm
thinking of the circular exposed, but captured, ball bearings that I found
in my Schwinn bicycle hub when I disassembled it as a child in the 1970's).
Can someone please enlighten me? I'd really like to see some pictures! I
can't find anything via Google.
If there is a bearing that gets sandwiched between these pieces, does
anyone know where I can get one?
Thanks!
Ken, KA6KEN
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