X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from smtp122.sbc.mail.re3.yahoo.com ([66.196.96.95] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with SMTP id 3752055 for flyrotary@lancaironline.net; Fri, 10 Jul 2009 08:19:23 -0400 Received-SPF: neutral receiver=logan.com; client-ip=66.196.96.95; envelope-from=bryanwinberry@bellsouth.net Received: (qmail 94507 invoked from network); 10 Jul 2009 12:18:47 -0000 Received: from unknown (HELO acer7fbfa7e2f7) (bryanwinberry@98.88.103.180 with login) by smtp122.sbc.mail.re3.yahoo.com with SMTP; 10 Jul 2009 12:18:46 -0000 X-YMail-OSG: aWINZTUVM1mb1vti4k7a75w6F8PDZuNCWlFP3hlaMEYpXZMSRn6pkGKFhYXGOHZaWZ54bu2gSYsxRLM3SmMD7e0iZlT30r0GmrO.T9lkGcimjSHg7Gzts7VW0SHaMivJf28oQfQzq1YNLSAUngmoz3MfQ3Jm_OnhZE99Y17Ob3BGV.Ta0Z7h1av54UBQ2H_91sdY4z4kcbNUYfLQEvcEDmeZlGdgOkG6CYlJseZRjFUX6MDRGzTW7D3zGsDsvAupQeBvZQ.iv6DHla91sYUHsOFqff3xtixsCLpOa2KEwPJdg8lUF9Qfm_Ue_bE- X-Yahoo-Newman-Property: ymail-3 From: "Bryan Winberry" To: "'Rotary motors in aircraft'" References: Subject: RE: [FlyRotary] Re: Interested in cog-belt PRSUs? Date: Fri, 10 Jul 2009 08:18:43 -0400 Message-ID: <200E9972902348A983D0BAAA8696DC9F@acer7fbfa7e2f7> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0026_01CA0137.0BD11000" X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcoBWEpfJeAatbuUToGMhHSaapkUcQAADNyw In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 This is a multi-part message in MIME format. ------=_NextPart_000_0026_01CA0137.0BD11000 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Disregard. I see now hat it is minus in the second paragraph. Sorry, BW _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bryan Winberry Sent: Friday, July 10, 2009 8:16 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Interested in cog-belt PRSUs? George you lost me with (81-45)/2=1.8 I get .9 Bryan _____ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich Sent: Friday, July 10, 2009 3:21 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: Interested in cog-belt PRSUs? Bernie, The calculations for ratio of this kind is (ring gear divided by sun gear). Using teeth numbers on the ring gear divided by the teeth numbers on the sun gear; If you had 81 teeth on the ring gear and 45 teeth on the sun gear i.e. (81/45=1.8). Now if there were an intermediate gear as on the planetary i.e. planetary gear - then the calculation for the planetary gear teeth. is; ring gear minus sun gear divided by two i.e.( 81- 45)/2 = 18. As a planetary runs with 3 gears, the prop runs the same way if the planetary is held (in place) by the ring gear, the calculations are 1.85 +1 = 2.85:1 Ratio. As the rotary runs anti-clockwise in out orientation ( from the rear of the motor forward ) we have a clockwise prop direction when using a planetary PSRU, with ring gear held. With the planet housing held it would run anti-clockwise and would be 1.8:1 However we only have two gears (sprockets) in this belt PSRU so ir must run in the direction the motor runs i.e. anti-clockwise. The ratio is similar to the Ford planetary which is 1.85:1. I don't really know the numbers of the teeth on the belt PSRU sprockets but used the numbers abovementioned as demonstration only. Hope that's clearer!? George (down under) "With the rotary, that would mean an anti-clockwise prop rotation, view from the cockpit, 1.8:1 is right on the mark as compared to the Ford planetary reduction which is 2.85:1 with clockwise rotation i.e. 1.85+1. George (down under)." I am totally confused about having two different ratios going from clockwise prop rotation to anti-clockwise for the same engine speed and prop speed. I am way out of my depth here. HELP!!! Bernie ------=_NextPart_000_0026_01CA0137.0BD11000 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable

Disregard.  I see now hat it = is minus in the second paragraph.

Sorry,

BW

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bryan Winberry
Sent: Friday, July 10, = 2009 8:16 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Interested in cog-belt PRSUs?

 

George you lost me with = (81-45)/2=3D1.8

I get = .9

Bryan

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of George Lendich
Sent: Friday, July 10, = 2009 3:21 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: = Interested in cog-belt PRSUs?

 

Bernie,

The calculations for ratio of this kind is (ring gear divided by sun gear). Using teeth numbers on the ring = gear divided by the teeth numbers on the sun gear; If you had 81 teeth on the ring gear = and 45 teeth on the sun gear i.e. (81/45=3D1.8).

 

Now if there were an intermediate gear as on the = planetary i.e. planetary gear - then the calculation for the planetary gear teeth. = is; ring gear minus sun gear divided by two i.e.( 81- 45)/2 =3D 18. As = a planetary runs with 3 gears, the prop runs the same way if the = planetary is held (in place) by the ring gear,  the calculations are 1.85 +1 = =3D 2.85:1 Ratio.

 

As the rotary runs anti-clockwise in out orientation = ( from the rear of the motor forward ) we have a clockwise prop direction when = using a planetary PSRU, with ring gear held. With the planet housing held it = would run anti-clockwise and would be 1.8:1

 

However we only have two gears (sprockets) in this = belt PSRU so ir must run in the direction the motor runs i.e. anti-clockwise. The ratio is = similar to the Ford planetary which is 1.85:1.

I don't really know the numbers of the teeth on the = belt PSRU sprockets but used the numbers abovementioned as demonstration = only.

Hope that's = clearer!? 

George (down under)

"With the rotary, that would mean an anti-clockwise prop rotation, view from
the cockpit, 1.8:1 is right on the mark as compared to the Ford = planetary
reduction which is 2.85:1 with clockwise rotation i.e. 1.85+1.
George (down under)."

I am totally confused about having two different ratios going from = clockwise prop rotation to anti-clockwise for the same engine speed and prop = speed. I am way out of my depth here. HELP!!! =       Bernie =

------=_NextPart_000_0026_01CA0137.0BD11000--