X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from ms-smtp-02.southeast.rr.com ([24.25.9.101] verified) by logan.com (CommuniGate Pro SMTP 5.1.9) with ESMTP id 2061862 for flyrotary@lancaironline.net; Tue, 22 May 2007 16:48:35 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.101; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-02.southeast.rr.com (8.13.6/8.13.6) with SMTP id l4MKlbCJ003597 for ; Tue, 22 May 2007 16:47:37 -0400 (EDT) Message-ID: <001101c79cb2$b1af0ea0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Gear box oil temps Date: Tue, 22 May 2007 16:49:29 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000E_01C79C91.2A405A80" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_000E_01C79C91.2A405A80 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Don't mind at all, Al. I like to do it - as at least it gives a sort of = ball-park figure of what to expect. Sounds like to me that your temps are not out of line. 243F with a 210F = input would lead me to 'expect" around 210F with a 180F oil temp going = in which I would certainly think was reasonable. I agree, I think a temp reading is more useful than a chip detector - = could give you a warning long before metal chips started appearing. Ed ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Tuesday, May 22, 2007 4:36 PM Subject: [FlyRotary] Re: Gear box oil temps 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. =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. 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=20 ------=_NextPart_000_000E_01C79C91.2A405A80 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Don't mind at all, Al.  I like to do it - = as at least=20 it gives a sort of ball-park figure of what to expect.
 
Sounds like to me that your temps are not out of = line.  243F with a 210F input would lead me to 'expect" around 210F = with a=20 180F oil temp going in which I would certainly think was=20 reasonable.
 
I agree, I think a temp reading is more useful = than a chip=20 detector - could give you a warning long before metal chips started=20 appearing.
 
Ed
----- Original Message -----
From:=20 Al = Gietzen=20
Sent: Tuesday, May 22, 2007 = 4:36 PM
Subject: [FlyRotary] Re: Gear = box oil=20 temps

Figures I found on the = web=20 indicates 3% is a fairly standard figure used for a planetary gearbox=20 efficiency.

So 3% of 160 HP =3D 4.8 = HP =20 which is mostly converted to heat.

 

Tf =3D 180F + (203/((7.3 = *.5) *0.4) =3D 180F = + 69F       =3D=20 249F

 

So using this example = and assuming=20 I haven't screwed up,  I would expect the oil temps coming out of = the=20 gear box to be around 249F. 

 

Ed;

I really = appreciate=20 when you take the time and effort to do the math that I=92m to lazy to = do.

I think = at the time=20 I noted the re-drive temp out it was 243F, shortly after leveling off = from a=20 climb, and the oil temp (after cooler, into drive) was still about = 210F. I=92m=20 gonna guess the power at that point was about 140 hp.  So it = seems that=20 the efficiency and/or the flow rate is a bit higher.  In any = case; I=92ll=20 proceed on with worrying about that outlet temp.

 

Thanks.

 

BTW; I = think that=20 monitoring the redrive outlet is important.  It can give you a = heads up=20 on problems with the redrive.  It is nice to be able to set a = limit in=20 the EM to alert you of a potential problem.

 

Al=20

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