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Thanks Tracy - I appreciate your
comments!
George ( down under)
----- Original Message -----
Sent: Tuesday, January 20, 2009 7:02
AM
Subject: [FlyRotary] Re: Thrust
bearings
INA, but that does not necessarily mean they are better
quality. There are MANY ways to spec the bearing. Your book may
have been giving a worst case number. L10 life spec is what I typically
try to use unless the application just can't fit around those. Sometimes
you have to give up 10,000 hour life for other
considerations.
Tracy
On Mon, Jan 19, 2009 at 3:41 PM, George Lendich <lendich@optusnet.com.au>
wrote:
Thanks Tracy,
These speeds are much higher than those in my
books, quite obviously a better quality product - can you tell me what brand
they are?
George ( down under)
-----
Original Message -----
Sent:
Tuesday, January 20, 2009 3:52 AM
Subject:
[FlyRotary] Re: Thrust bearings
I've learned it's rarely wise to debate these kind of
things but FWIW, needle bearing rpm capabilities are not simple to nail
down. You might notice that this same (or very close) sized bearing
(a single stage at that) is used in the 13B itself and of course it does
not limit the engine to 2800 rpm. Needle bearing ratings are also
sensitive to lubrication schemes. The thrust bearing in the RD-1 is
pressure fed to insure the best possible lubrication and cooling
environment.
If it gives you any comfort, check it out on www.Mcmaster.com website
(pg 1135 of catalog) and you will note that the 35mm x 52mm needle bearing
at a dynamic load of 4000 lbs is rated up to 6500 rpm in a single
stack. In a double stack, that gives you a good margin well over
10,000 rpm.
Hope this puts your mind at
ease.
Tracy
On Sun, Jan 18, 2009 at 6:23 PM, George Lendich
<lendich@optusnet.com.au> wrote:
Tracy.
On
another subject, I was looking at your web site and noticed the
different Sun gear thrust bearing stages and notice you went from
Ball bearing ( failed) to roller bearing - to what appears to be
2 back to back needle bearings with their end and intermediate
washers.
Looking at the bearing book, I notice a limit of about
2,800 rpm on needle bearings which give only 5.600 rpm limit.
My
question is, wouldn't 3 needle thrust bearings be needed and could you
use 2 thrust ball bearings back to back which run at 5,600 rpm
each?
I guess it would be way over kill but NSK double direction
angular contact thrust ball bearings, run to 9,500 rpm.
Did you
consider any of these other options? or was space your over riding
factor
George (down under)
Steve:
Any reaction from the Dept of Homeland Security to that muffler?
:>)
Tracy
On Sun, Jan 18, 2009 at 4:01 PM, Steven
Boese <sboese@uwyo.edu> wrote:
Mike,
The
length of the cylindrical section is 24 inches. The conical
section is
9 inches long.
The dome was made from a Kmart
mixing bowl. Some of it is less than 0.032
inches
thick but has held up so far.
The cylindrical section was
made by a local sheet metal shop with a stove
pipe joint that
also has been tack welded in a few places.
I made the conical
section, inside parts, heat shield, and mount from the
same sheet
material as the cylindrical section. The joint in the
conical
section is similar to the stove pipe joint and is also
tack welded.
Steve
Boese
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