X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=cpHlbGwi c=1 sm=1 tr=0 a=1uaG66P5D6DV9FJSSGzPyA==:117 a=9lSN37m379oECu5yH2MVbQ==:17 a=x7bEGLp0ZPQA:10 a=VqmtQeTB-p0A:10 a=4_-BN3WEXhEA:10 a=3JhidrIBZZsA:10 a=zVD3-muSTbfp9Mt2WgoA:9 a=QEXdDO2ut3YA:10 a=Fzxfb-H1F4MA:10 a=yMhMjlubAAAA:8 a=SSmOFEACAAAA:8 a=Ia-xEzejAAAA:8 a=gXjoHxmNPaoU_wi2:21 a=gKO2Hq4RSVkA:10 a=UiCQ7L4-1S4A:10 a=hTZeC7Yk6K0A:10 a=frz4AuCg-hUA:10 a=Urk15JJjZg1Xo0ryW_k8:22 a=pHzHmUro8NiASowvMSCR:22 a=n87TN5wuljxrRezIQYnT:22 From: "Tracy Crook rwstracy@gmail.com" Received: from mail-yb1-f178.google.com ([209.85.219.178] verified) by logan.com (CommuniGate Pro SMTP 6.2.10) with ESMTPS id 12098251 for flyrotary@lancaironline.net; Sun, 13 Jan 2019 09:49:33 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.219.178; envelope-from=rwstracy@gmail.com Received: by mail-yb1-f178.google.com with SMTP id a190so7695781ybg.3 for ; Sun, 13 Jan 2019 06:49:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:mime-version:to:from:subject:date:importance:in-reply-to :references; bh=7DboZTleTKmB9FOtZ8kRlyJVdLtEXVbWicLLUmpW+Cg=; b=mEtKLx3yrtZsi7TeTlrLkLP/81TlHKCuxLKBase64XPs86qHtxrgzMpqyLOWBM3lXO BgnoNDL5+RPi3l/eKNSV9HRerRv7VFAvC5abALISuCAzuRVXuu5gOhy77G6+EyUTazr5 aRJ5zbEC9iiJLlAZqrnpMe1eNhLQmg0J+XAYF0wfuiUPHici2q28MIX5fcBlTq9tCmqd Os2uEzFAO6nUTxxviO+o4S4cXsqqxn7N+xHagkpOlu6gcTcnrh0cqnUzvV4/+c2KYc6O g7hbKUyDO/VoZQkh0INj0VGLZVuqMbuHKY3TE/gJM94/2Wxj6ogQsrwMzm29suCKu7fI 6gQw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:mime-version:to:from:subject:date :importance:in-reply-to:references; bh=7DboZTleTKmB9FOtZ8kRlyJVdLtEXVbWicLLUmpW+Cg=; b=GSrcX8FJiqdXSYvRtMlaICXl2Z2ivYLVdbTtS6+W6OQYlbpH489ezja4DCV6gWPUNX RJpjiMFDyMDESpi4Sp4hnDvgeTFm/XwOy89yCzEsRi2En+ajb8nAAeAiY6ESlte4HtHT kDiazoLTiKPiVz5WcAoLYnsHVjYLk7xxYlvEynniypZMOxUf4aOzzsVlPiJQaSzAyB9b JwNkZF4DwOS83/tfNIJple2ChvNqmsadCLJVSUo2vP/ys0F1iNcZwoSGeAGzPgQHNqfr /eFKUk7KAPrF8YbC/JuRJFxzDr59MJDMvDuKcZM7s541rCjLS8hqCczAUAy1PIFyuUFg EByg== X-Gm-Message-State: AJcUukek86xo1DKLPJGCEobMms/L+VTXbjpZptRzQSIyAHsw2V+5QUmZ w+6GtQBIbcVqObcNR1K02Wvi4z9W X-Google-Smtp-Source: ALg8bN4mVvZRfTUiplq9GecQZggQgqyP2Pd/Ufm3Af0f+xKcD0qFBTmr0bG0HIT2FG3BIq6HmJ6T7Q== X-Received: by 2002:a25:5441:: with SMTP id i62mr20118079ybb.152.1547390954873; Sun, 13 Jan 2019 06:49:14 -0800 (PST) Return-Path: Received: from ?IPv6:::ffff:192.168.254.69? (h44.164.213.151.dynamic.ip.windstream.net. [151.213.164.44]) by smtp.gmail.com with ESMTPSA id k64sm29695691ywc.56.2019.01.13.06.49.13 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 13 Jan 2019 06:49:13 -0800 (PST) Message-ID: <5c3b4fe9.1c69fb81.96ede.a233@mx.google.com> MIME-Version: 1.0 To: Rotary motors in aircraft Subject: RE: [FlyRotary] stacked thrust bearing Date: Sun, 13 Jan 2019 09:49:13 -0500 Importance: normal X-Priority: 3 In-Reply-To: References: Content-Type: multipart/alternative; boundary="_A3D8EA56-1CF7-4798-AC6C-8C502CD9CBEF_" --_A3D8EA56-1CF7-4798-AC6C-8C502CD9CBEF_ Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Awesome work Steve. =20 I suspected but did not know as fact that the drive filled with oil, partic= ularly on the C drive. The B drive incorporates a pumping mechanism formed= by the spinning ring gear and a sloped pocket machined into the housing. = How effective this is I do not know but it was not possible to do the same = on the C drive since the ring gear is stationary. I accepted the possible = power losses from excessive oil rather than going for the weight and comple= xity of a scavenging pump. =20 I should also add that I do not know for sure that the stacked needle beari= ngs are actually needed in the C drive. The single roller bearing in the B= drive may be adequate and it is the same thickness as the two stacked need= le bearings. This would eliminate the shaft and race wear problem complete= ly. I plan to change over to the B drive bearing the next time I look ins= ide the drive. Even if the life of the bearing was reduced by 90% it would= still be a 1000 hour replacement interval. I realize that bearing wear is= not linear with speed though. Still stuck at the house for the last month due to the river flooding the r= oad to Shady Bend. Down to my last frozen pizza, hope it don=E2=80=99t rai= n and the creek don=E2=80=99t rise =F0=9F=98=8A Tracy Sent from Mail for Windows 10 From: Steven W. Boese SBoese@uwyo.edu Sent: Saturday, January 12, 2019 9:41 PM To: Rotary motors in aircraft Subject: [FlyRotary] stacked thrust bearing Tracy and Neil, In order to prove to myself that the RPM is divided between the stacked thr= ust bearings, I installed a Hall effect sensor in the mounting plate and si= lver brazed triggers to the middle thrust washer.=C2=A0 An inductive pickup= was installed to monitor the rotation of the flexplate (input shaft).=C2= =A0 This allowed the determination of the input shaft RPM as well as the mi= ddle washer RPM under various conditions. The load on the drive was from a = 3 blade 72" dia=C2=A0 Warp drive prop with the tip angle set to 20 degrees.= =C2=A0=C2=A0 All new bearing components as used in the -C drive were tested along with a= used cupped middle thrust washer from a C6 transmission.=C2=A0 The cupped = thrust washer was tested because it was possible that the cup overlapping t= he 3.5mm shaft side thrust washer would prevent the middle washer from cont= acting and causing wear of the input shaft.=C2=A0 After seeing the results = from the used cupped washer, new cupped washers were obtained and tested al= so. In the course of testing the thrust bearing configurations, it was found th= at the reduction drive always operates completely filled with oil.=C2=A0 Th= e added triggers may have affected the behavior of the bearing stack due to= drag between them and the surrounding oil.=C2=A0 To see if this was the ca= se, the drive was modified such that the drive contained about 5 to 6 oz of= oil during operation rather than the about 20 oz of oil when completely fi= lled. The results are shown in the attached plots. These results indicate that, with all new components including a new flat m= iddle washer, the RPM was reasonably well divided between the two thrust be= arings and affected little by the amount of oil in the gearbox.=C2=A0 With = the used cupped middle thrust washer, essentially all the RPM was seen by t= he mounting plate side bearing.=C2=A0 With the new cupped middle thrust was= her, the RPM=C2=A0 distribution between the thrust bearings was affected by= engine RPM when the gearbox was completely oil filled but little affected = by RPM when the gearbox was drained. All the results were obtained with an input shaft that didn't have a groove= worn in it by the middle thrust washer. =C2=A0 My conclusion is that with all new bearing components and unworn shaft the = system behaves as desired.=C2=A0 With used components, the behavior is unkn= own.=C2=A0 The cupped thrust washer is not a solution to the shaft wear iss= ue because of the uneven RPM distribution when submerged in oil and since s= haft wear has resulted from the bearing cages as well as the middle washer.= =C2=A0 The internal gearbox pressure with -6 drain lines was about 4 psi when cold= and about 2 psi when warm which may have implications in terms of input se= al leakage and the seal coming out of its bore.=C2=A0 The completely oil fi= lled gearbox consumes extra power which is converted to heat but apparently= not so much as to cause serious problems. All the above are simply results of my curiosity.=C2=A0 You are most welcom= e to draw your own conclusions. Steve Boese =C2=A0 --_A3D8EA56-1CF7-4798-AC6C-8C502CD9CBEF_ Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="utf-8"

Awesome work Steve.=C2=A0

 

I suspected but di= d not know as fact that the drive filled with oil, particularly on the C dr= ive.=C2=A0 The B drive incorporates a pumping mechanism formed by the spinn= ing ring gear and a sloped pocket machined into the housing.=C2=A0 How effe= ctive this is I do not know but it was not possible to do the same on the C= drive since the ring gear is stationary.=C2=A0 I accepted the possible pow= er losses from excessive oil rather than going for the weight and complexit= y of a scavenging pump.=C2=A0

 

I should also add that I do not know for sure that th= e stacked needle bearings are actually needed in the C drive.=C2=A0 The sin= gle roller bearing in the B drive may be adequate and it is the same thickn= ess as the two stacked needle bearings. =C2=A0This would eliminate the shaf= t and race wear problem completely. =C2=A0=C2=A0I plan to change over to th= e B drive bearing the next time I look inside the drive. =C2=A0Even if the = life of the bearing was reduced by 90% it would still be a 1000 hour replac= ement interval.=C2=A0 I realize that bearing wear is not linear with speed = though.

 

S= till stuck at the house for the last month due to the river flooding the ro= ad to Shady Bend.=C2=A0 Down to my last frozen pizza, hope it don=E2=80=99t= rain and the creek don=E2=80=99t rise 😊

 

Tracy

 =

Sent from Mail for Windows 10

&= nbsp;

From: Steven W. Boese SBoese@uwyo.edu
Sent: Saturd= ay, January 12, 2019 9:41 PM
To: Rotary motors in aircraft
Subject: [FlyRotary]= stacked thrust bearing

 

=

 

Tracy and Neil,

 

In order to prove to myself that the RPM is divide= d between the stacked thrust bearings, I installed a Hall effect sensor in = the mounting plate and silver brazed triggers to the middle thrust washer.&= nbsp; An inductive pickup was installed to monitor the rotation of the flex= plate (input shaft).  This allowed the determination of the input shaf= t RPM as well as the middle washer RPM under various conditions. The load o= n the drive was from a 3 blade 72" dia  Warp drive prop with the = tip angle set to 20 degrees.   

 

All new bearing components as used in = the -C drive were tested along with a used cupped middle thrust washer from= a C6 transmission.  The cupped thrust washer was tested because it wa= s possible that the cup overlapping the 3.5mm shaft side thrust washer woul= d prevent the middle washer from contacting and causing wear of the input s= haft.  After seeing the results from the used cupped washer, new cuppe= d washers were obtained and tested also.

 

In the course of testing the thrust bea= ring configurations, it was found that the reduction drive always operates = completely filled with oil.  The added triggers may have affected the = behavior of the bearing stack due to drag between them and the surrounding = oil.  To see if this was the case, the drive was modified such that th= e drive contained about 5 to 6 oz of oil during operation rather than the a= bout 20 oz of oil when completely filled.

 

The results are shown in the attached = plots.

 

These results indicate that, with all new components including a new flat= middle washer, the RPM was reasonably well divided between the two thrust = bearings and affected little by the amount of oil in the gearbox.  Wit= h the used cupped middle thrust washer, essentially all the RPM was seen by= the mounting plate side bearing.  With the new cupped middle thrust w= asher, the RPM  distribution between the thrust bearings was affected = by engine RPM when the gearbox was completely oil filled but little affecte= d by RPM when the gearbox was drained.

 

All the results were obtained with an in= put shaft that didn't have a groove worn in it by the middle thrust washer.=  

 

My conclusion is that with all new bearing components and unworn shaft t= he system behaves as desired.  With used components, the behavior is u= nknown.  The cupped thrust washer is not a solution to the shaft wear = issue because of the uneven RPM distribution when submerged in oil and sinc= e shaft wear has resulted from the bearing cages as well as the middle wash= er. 

 

The internal gearbox pressure with -6 drain lines was about 4 psi when= cold and about 2 psi when warm which may have implications in terms of inp= ut seal leakage and the seal coming out of its bore.  The completely o= il filled gearbox consumes extra power which is converted to heat but appar= ently not so much as to cause serious problems.

 

All the above are simply results= of my curiosity.  You are most welcome to draw your own conclusions.<= o:p>

&= nbsp;

Steve= Boese  

 

 

= --_A3D8EA56-1CF7-4798-AC6C-8C502CD9CBEF_--