Return-Path: Received: from [65.54.168.112] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 536120 for flyrotary@lancaironline.net; Wed, 17 Nov 2004 11:43:33 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.168.112; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Wed, 17 Nov 2004 08:43:01 -0800 Received: from 65.54.98.156 by BAY3-DAV8.phx.gbl with DAV; Wed, 17 Nov 2004 16:42:48 +0000 X-Originating-IP: [65.54.98.156] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Post Mortem on Steve Brooks RD-1B Date: Wed, 17 Nov 2004 11:42:48 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0063_01C4CC9A.8FDA3A10" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0009.2900 Seal-Send-Time: Wed, 17 Nov 2004 11:42:48 -0500 Message-ID: X-OriginalArrivalTime: 17 Nov 2004 16:43:01.0746 (UTC) FILETIME=[80A96D20:01C4CCC4] This is a multi-part message in MIME format. ------=_NextPart_000_0063_01C4CC9A.8FDA3A10 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Tommy, we need all the honest info we can get in this game. Perry Mick asked: If there was a restriction in the oil line going to the drive, such that = the=20 drive "saw" a low oil pressure, could that cause something like this? = Just a=20 thought... I doubt it, the allowable range of oil pressure at the drive is pretty = wide, about 25 - 100 psi. Even a momentary drop to zero would not be = catastrophic. Tracy ----- Original Message -----=20 From: Tommy James=20 Thanks T,=20 An honest man may be hard to find, but appreciated by all who know = him. Tommy<>< -------------------------------------------------------------------------= ----- Subject: [FlyRotary] Re: Post Mortem on Steve Brooks RD-1B Total time on drive was 20 hours. Steve noticed the problem as an = oil leak from the input shaft oil seal. Internal inspection showed the = input shaft thrust bearing roller cage which is a polymer cage to be = partially melted and most of the rollers were out of the cage. Overheat = was the obvious cause of cage failure. Rear race of bearing was seized = on input shaft and was 'blued' from heat. This allowed the shaft to move = back and contact the adapter plate. All sorts of nastiness resulted = from this but the details are not as important as the root cause. = Amazingly, the drive continued to operate normally but the time between = roller cage failure and discovery of the problem is unknown.=20 The oil passage from the input shaft pilot bearing to the thrust = bearing was found to be clogged and no oil was getting to the thrust = bearing (except for incidental splash). What caused the clog has not = been determined. I will attempt to carefully grind away the input gear = and see what it was as time permits.=20 =20 The rear race was spinning against the adapter plate and acting as the = thrust bearing while being lubricated only with splash. That Mobile 1 = is amazing stuff! A careful inspection of the gears showed no evidence of damage or = wear. Corrective action: Replaced the input shaft assembly and thrust = bearing, installed nylon snubber/spacer to bring input shaft endplay = into spec. Tracy Crook, RWS ------=_NextPart_000_0063_01C4CC9A.8FDA3A10 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Thanks Tommy, we need all the honest info we can get in this=20 game.

Perry Mick asked:

If there was a restriction in the oil line going to the drive, such = that=20 the
drive "saw" a low oil pressure, could that cause something like = this?=20 Just a
thought...

I doubt it, the allowable range of oil pressure at the drive is = pretty=20 wide, about 25 - 100 psi. Even a momentary drop to zero = would not be=20 catastrophic.

Tracy

----- Original Message -----

From: Tommy James

Thanks T,=20

An honest = man may be=20 hard to find, but appreciated by all who know him.

Tommy<><

Subject: [FlyRotary] Re: Post = Mortem on=20 Steve Brooks RD-1B

Total = time on=20 drive was 20 hours.   Steve noticed the problem as an oil = leak from=20 the input shaft oil seal. Internal inspection showed = the input=20 shaft thrust bearing roller cage which is a polymer cage to be = partially=20 melted and most of the rollers were out of the cage. Overheat = was the=20 obvious cause of cage failure. Rear race of bearing was seized = on input=20 shaft and was 'blued' from heat. This allowed the shaft to move back = and=20 contact the adapter plate. All sorts of nastiness resulted from = this but=20 the details are not as important as the root cause. Amazingly, = the drive=20 continued to operate normally but the time between roller cage failure = and=20 discovery of the problem is unknown.

The oil = passage=20 from the input shaft pilot bearing to the thrust bearing was found to = be=20 clogged and no oil was getting to the thrust bearing (except for = incidental=20 splash). What caused the clog has not been determined. I = will=20 attempt to carefully grind away the input gear and see what it was as = time=20 permits.

=20

The rear = race was=20 spinning against the adapter plate and acting as the thrust bearing = while=20 being lubricated only with splash. That Mobile 1 is amazing=20 stuff!

A = careful=20 inspection of the gears showed no evidence of damage or=20 wear.

Corrective=20 action:  Replaced the input shaft assembly and thrust = bearing,=20 installed nylon snubber/spacer to bring input shaft endplay into=20 spec.

Tracy=20 Crook,  =20 RWS

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