Return-Path: Received: from [65.54.169.62] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2.5) with ESMTP id 534614 for flyrotary@lancaironline.net; Tue, 16 Nov 2004 11:15:05 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.169.62; envelope-from=lors01@msn.com Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Tue, 16 Nov 2004 08:14:01 -0800 Received: from 65.54.98.157 by BAY3-DAV32.phx.gbl with DAV; Tue, 16 Nov 2004 16:13:12 +0000 X-Originating-IP: [65.54.98.157] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: Post Mortem on Steve Brooks RD-1B Date: Tue, 16 Nov 2004 11:10:33 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0056_01C4CBCC.E3E59F60" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.10.0009.2900 Seal-Send-Time: Tue, 16 Nov 2004 11:10:33 -0500 Message-ID: X-OriginalArrivalTime: 16 Nov 2004 16:14:01.0682 (UTC) FILETIME=[4916FB20:01C4CBF7] This is a multi-part message in MIME format. ------=_NextPart_000_0056_01C4CBCC.E3E59F60 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable 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_0056_01C4CBCC.E3E59F60 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Total time on drive was 20 hours. Steve noticed the = problem as=20 an oil leak from the input shaft oil seal. Internal = inspection=20 showed the input shaft thrust bearing roller cage which is a polymer = cage to be=20 partially melted and most of the rollers were out of the cage. = Overheat=20 was the obvious cause of cage failure. Rear race of bearing was = seized on=20 input 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 from the input shaft pilot bearing to the thrust = bearing=20 was found to be clogged and no oil was getting to the thrust bearing = (except for=20 incidental splash). What caused the clog has not been = determined. I=20 will attempt to carefully grind away the input gear and see what it was = as time=20 permits.

=20

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

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

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

Tracy Crook, RWS

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