X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ispmxmta05-srv.windstream.net ([166.102.165.166] verified) by logan.com (CommuniGate Pro SMTP 5.1.11) with ESMTP id 2210494 for flyrotary@lancaironline.net; Sat, 28 Jul 2007 19:18:17 -0400 Received-SPF: pass receiver=logan.com; client-ip=166.102.165.166; envelope-from=montyr2157@alltel.net Received: from ispmxaamta08-gx.windstream.net ([71.29.244.202]) by ispmxmta05-srv.windstream.net with ESMTP id <20070728231738.NHXQ19750.ispmxmta05-srv.windstream.net@ispmxaamta08-gx.windstream.net> for ; Sat, 28 Jul 2007 18:17:38 -0500 Received: from Thorstwin ([71.29.244.202]) by ispmxaamta08-gx.windstream.net with SMTP id <20070728231738.DVYD7089.ispmxaamta08-gx.windstream.net@Thorstwin> for ; Sat, 28 Jul 2007 18:17:38 -0500 Message-ID: <006501c7d16d$8323cb30$6501a8c0@Thorstwin> From: "M Roberts" To: "Rotary motors in aircraft" Subject: Gear Mesh Area Date: Sat, 28 Jul 2007 18:17:48 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0062_01C7D143.9A2C5880" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 This is a multi-part message in MIME format. ------=_NextPart_000_0062_01C7D143.9A2C5880 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Ed, My quick & dirty answer is that the 6 pinion planet set is equivalent to = a spur gear drive with a gear width totaling the width of all 6 planets. = That would be: 6 * .785" =3D 4.71" Thats a mighty big & heavy spur gear! =20 That's bigger than the one in a P-51 R.R. Merlin engine I think. Not an = apples to apples comparison due to the difference in bending strength of = the tooth root but the biggie factor in power handling capability is = indeed the gear contact patch.=20 Tracy The Merlin made about 2200 hp with a spur gear 2 in wide. So that is = roughly 1100 hp/in of linear contact. The Ford planetary would be 300/4.71 or 63.69 hp/in of contact. Not exactly an apples to apples comparison, but it gives you an idea of = how lightly loaded the Ford planetary is. Monty ------=_NextPart_000_0062_01C7D143.9A2C5880 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Hi Ed,

My quick & dirty answer is that the = 6 pinion=20 planet set is equivalent to a spur gear drive with a gear width totaling = the=20 width of all 6 planets. That would be:

6 * .785" =3D 4.71" = Thats a mighty=20 big & heavy spur gear!

That's bigger than the one in a P-51 = R.R. Merlin=20 engine I think. Not an apples to apples comparison due to the = difference=20 in bending strength of the tooth root but the biggie factor in = power=20 handling capability is indeed the gear contact patch.

Tracy

The Merlin made = about 2200 hp=20 with a spur gear 2 in wide. So that is roughly 1100 hp/in of linear=20 contact.

The Ford planetary = would be 300/4.71=20 or 63.69 hp/in of contact.

Not exactly an apples = to apples=20 comparison, but it gives you an idea of how lightly loaded the Ford = planetary=20 is.

Monty

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