X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 30 [X] Return-Path: Received: from fed1rmmtao103.cox.net ([68.230.241.43] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2061754 for flyrotary@lancaironline.net; Tue, 22 May 2007 15:36:08 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.43; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao103.cox.net (InterMail vM.7.05.02.00 201-2174-114-20060621) with ESMTP id <20070522193528.DIHI19731.fed1rmmtao103.cox.net@fed1rmimpo02.cox.net> for ; Tue, 22 May 2007 15:35:28 -0400 Received: from BigAl ([72.192.132.90]) by fed1rmimpo02.cox.net with bizsmtp id 2KbV1X00Y1xAn3c0000000; Tue, 22 May 2007 15:35:29 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Gear box oil temps Date: Tue, 22 May 2007 12:36:01 -0800 Message-ID: <000001c79cb0$cfb23b90$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C79C6D.C18EFB90" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C79C6D.C18EFB90 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Figures I found on the web indicates 3% is a fairly standard figure used = for a planetary gearbox efficiency. So 3% of 160 HP =3D 4.8 HP which is mostly converted to heat. =20 Tf =3D 180F + (203/((7.3 *.5) *0.4) =3D 180F + 69F =3D 249F =20 So using this example and assuming I haven't screwed up, I would expect = the oil temps coming out of the gear box to be around 249F. =20 =20 Ed; I really appreciate when you take the time and effort to do the math = that I'm to lazy to do. I think at the time I noted the re-drive temp out it was 243F, shortly = after leveling off from a climb, and the oil temp (after cooler, into drive) = was still about 210F. I'm gonna guess the power at that point was about 140 = hp. So it seems that the efficiency and/or the flow rate is a bit higher. = In any case; I'll proceed on with worrying about that outlet temp. =20 Thanks. =20 BTW; I think that monitoring the redrive outlet is important. It can = give you a heads up on problems with the redrive. It is nice to be able to = set a limit in the EM to alert you of a potential problem. =20 Al=20 ------=_NextPart_000_0001_01C79C6D.C18EFB90 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

Figures I found on the web = indicates 3% is a fairly standard figure used for a planetary gearbox = efficiency.

So 3% of 160 HP =3D 4.8 = HP which is mostly converted to heat.

Tf =3D 180F + (203/((7.3 *.5) *0.4) =3D 180F + 69F = =3D 249F

So using this example and = assuming I haven't screwed up, I would expect the oil temps coming out of the = gear box to be around 249F.

Ed;

I really appreciate when you take = the time and effort to do the math that I’m to lazy to = do.

I think at the time I noted the = re-drive temp out it was 243F, shortly after leveling off from a climb, and the = oil temp (after cooler, into drive) was still about 210F. I’m gonna guess = the power at that point was about 140 hp. So it seems that the = efficiency and/or the flow rate is a bit higher. In any case; I’ll proceed on = with worrying about that outlet temp.

Thanks.

BTW; I think that monitoring the = redrive outlet is important. It can give you a heads up on problems with = the redrive. It is nice to be able to set a limit in the EM to alert you of a = potential problem.

Al

------=_NextPart_000_0001_01C79C6D.C18EFB90--