X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail09.syd.optusnet.com.au ([211.29.132.190] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTPS id 3434091 for flyrotary@lancaironline.net; Mon, 19 Jan 2009 15:42:05 -0500 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.190; envelope-from=lendich@optusnet.com.au Received: from george (d220-236-171-208.dsl.nsw.optusnet.com.au [220.236.171.208]) by mail09.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id n0JKfL2H001046 for ; Tue, 20 Jan 2009 07:41:22 +1100 Message-ID: <1328684000A94087A903A620768DA8B3@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Thrust bearings Date: Tue, 20 Jan 2009 06:41:25 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0045_01C97ACA.1DB7D860" 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_0045_01C97ACA.1DB7D860 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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_0045_01C97ACA.1DB7D860 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
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)
----- Original Message -----
From:=20 Tracy=20 Crook
Sent: Tuesday, January 20, 2009 = 3:52=20 AM
Subject: [FlyRotary] Re: Thrust = bearings

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

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

Hope = this=20 puts your mind at ease.

Tracy


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

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

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

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

Did you consider any of these other options? or was = space your=20 over riding 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 = thick=20 but has held up so far.

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

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



Steve = Boese


--
Homepage:=20  http://www.flyrotary.com/
Archive and = UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.htm= l=20


--
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