X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail05.syd.optusnet.com.au ([211.29.132.186] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTPS id 3434344 for flyrotary@lancaironline.net; Mon, 19 Jan 2009 20:20:41 -0500 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.186; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-171-208.dsl.nsw.optusnet.com.au [220.236.171.208]) by mail05.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id n0K1JwIo020758 for ; Tue, 20 Jan 2009 12:19:59 +1100 Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Thrust bearings Date: Tue, 20 Jan 2009 11:20:02 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0023_01C97AF1.09A3DA50" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 090119-0, 19/01/2009), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0023_01C97AF1.09A3DA50 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Tracy - I appreciate your comments! George ( down under) ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 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 = 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 -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 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.=20 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 = 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 = 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 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html=20 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0023_01C97AF1.09A3DA50 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Thanks Tracy - I appreciate your=20 comments!
George ( down under)
----- Original Message -----
From:=20 Tracy=20 Crook
Sent: Tuesday, January 20, 2009 = 7:02=20 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=20 have been giving a worst case number.  L10 life spec is what I = typically=20 try to use unless the application just can't fit around those.  = Sometimes=20 you have to give up 10,000 hour life for other=20 considerations.

Tracy

On Mon, Jan 19, 2009 at 3:41 PM, George = Lendich <lendich@optusnet.com.au>=20 wrote:
Thanks Tracy,
These speeds are much higher than = those in my=20 books, quite obviously a better quality product - can you tell me = what brand=20 they are?
George ( down under)
-----=20 Original Message -----
From:=20 Tracy Crook
To:=20 Rotary = motors in=20 aircraft
Sent:=20 Tuesday, January 20, 2009 3:52 AM
Subject:=20 [FlyRotary] Re: Thrust bearings

I've learned it's rarely wise to debate these kind = of=20 things but FWIW, needle bearing rpm capabilities are not simple to = nail=20 down.  You might notice that this same (or very close) sized = bearing=20 (a single stage at that) is used in the 13B itself and of course = it does=20 not limit the engine to 2800 rpm.  Needle bearing ratings are = also=20 sensitive to lubrication schemes.  The thrust bearing in the = RD-1 is=20 pressure fed to insure the best possible lubrication and cooling=20 environment.

If it gives you any comfort, check it out on = www.Mcmaster.com website=20 (pg 1135 of catalog) and you will note that the 35mm x 52mm needle = bearing=20 at a dynamic load of 4000 lbs is rated up to 6500 rpm in a single=20 stack.  In a double stack, that gives you a good margin well = over=20 10,000 rpm.

Hope this puts your mind at=20 ease.

Tracy


On Sun, Jan 18, 2009 at 6:23 PM, George = Lendich=20 <lendich@optusnet.com.au> wrote:
Tracy.
On=20 another subject, I was looking at your web site and noticed the=20 different Sun gear thrust bearing stages and notice you went = from=20  Ball bearing ( failed) to roller bearing - to what appears = to be=20  2 back to back needle bearings with their end and = intermediate=20 washers.

Looking at the bearing book, I notice a limit of = about=20 2,800 rpm on needle bearings which give only 5.600 rpm = limit.

My=20 question is, wouldn't 3 needle thrust bearings be needed and = could you=20 use 2 thrust ball bearings back to back which run at 5,600 rpm=20 each?

I guess it would be way over kill but NSK double = direction=20 angular contact thrust ball bearings, run to 9,500 = rpm.

Did you=20 consider any of these other options? or was space your over = riding=20 factor
George (down under)

Steve:=20 Any reaction from the Dept of Homeland Security to that = muffler?=20 :>)

Tracy


On Sun, Jan 18, 2009 at 4:01 = PM, Steven=20 Boese <sboese@uwyo.edu> wrote:
Mike,



The=20 length of the cylindrical section is 24 inches.  The = conical=20 section is
9 inches long.

The dome was made from a = Kmart=20 mixing bowl.  Some of it  is less than = 0.032
inches=20 thick but has held up so far.

The cylindrical section = was=20 made by a local sheet metal shop with a stove
pipe joint = that=20 also has been tack welded in a few places.

I made the = conical=20 section, inside parts, heat shield, and mount from = the
same sheet=20 material as the cylindrical section.  The joint in the=20 conical
section is similar to the stove pipe joint and is = also=20 tack welded.



Steve=20 Boese


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