X-Junk-Score: 0 [] X-Cloudmark-Score: 0 [] X-Cloudmark-Analysis: v=2.3 cv=cpHlbGwi c=1 sm=1 tr=0 a=nMnKDt7L5N/liDxpcIebAQ==:117 a=55z/sxGcUIPVrBMYBb4HRw==:17 a=x7bEGLp0ZPQA:10 a=_Z_nqdSeG58A:10 a=3JhidrIBZZsA:10 a=r77TgQKjGQsHNAKrUKIA:9 a=7g1VtSJxAAAA:8 a=Ia-xEzejAAAA:8 a=b_RsOHFVPXmHLOXHDzwA:9 a=Gdmb81hYodvjzsAN:21 a=_GUCKlHBakW3H0tG:21 a=pILNOxqGKmIA:10 a=Qa1je4BO31QA:10 a=gvSQh4r-fQ0A:10 a=4PR2P7QzAAAA:8 a=D8XuSezW0E7Rcv5Q3EQA:9 a=7Zwj6sZBwVKJAoWSPKxL6X1jA+E=:19 a=TzGKyAMSUPD7OuYB:21 a=XPhSCmVspbAUZe06:21 a=Nc_4rCERjkM_JBUv:21 a=_W_S_7VecoQA:10 a=frz4AuCg-hUA:10 a=grOzbf7U_OpcSX4AJOnl:22 a=Urk15JJjZg1Xo0ryW_k8:22 a=4dqwQCo7Po2mVW515mGf:22 From: "Neil Unger 12348ung@gmail.com" Received: from mail-pg1-f171.google.com ([209.85.215.171] verified) by logan.com (CommuniGate Pro SMTP 6.2.10) with ESMTPS id 12097700 for flyrotary@lancaironline.net; Sun, 13 Jan 2019 05:42:39 -0500 Received-SPF: pass receiver=logan.com; client-ip=209.85.215.171; envelope-from=12348ung@gmail.com Received: by mail-pg1-f171.google.com with SMTP id c25so8240844pgb.4 for ; Sun, 13 Jan 2019 02:42:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:references:from:message-id:date:user-agent:mime-version :in-reply-to:content-language; bh=9NFAdAAiVMrDu5VoyKlJE2Kai99FUAXBEgjFQY8lubk=; b=esWu68PoeqVoc51bvk9bqPLr5NJFO7Gn8lQF4DSKQJIBGh9Gyv6sCbbEURjO8Og8JC tXmsAxCxNcEuohJDFUE5wxfWuMpE377iT2QacubyH98ynRoDqA+EzjPHz0+wQOHCB+Rb elvzHP/5vwzAXW6fK/97M+4tC31/8lFGZmctXA+dbyH2eBbKOQZCN/KuLxClv0j2qq8q 98Bng9Uz2ucwMUwPn/kP/p9c3qxd0F0uzpx5surj93rIX7GHOhRG+Seykhil1VYNd8ro xrIPC1aC3YNMhS3u/fw2PFuDDUlF7AXJ4awx2ZK64WsRR4uekHeoAWCjV5/TUD6C/mf/ +ZDA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language; bh=9NFAdAAiVMrDu5VoyKlJE2Kai99FUAXBEgjFQY8lubk=; b=UqUfTpgKHXxqUaWS1AF+KcWWD24BqiSaHLzBrFOWklzFSwezBvc+0EBjUBfVN1v/j1 DX/RZDZPun/+59vrHBmEjxRq0GosrCJWLBO4/lRk9J98HhvIg2f48YveipLWRB0EX5pp 6T8vae1deAEc582XiXMR0eEuCBPPcqwi1EZFdykHlGo5Lg5OCQKxDFnUE3pqFoQ5inIG 0mWSlQRQITo5x0WLIXSzhr3XQ23/tZlzgZTR4EyS86R1N2sabQwxTKsmT+QoN+kb1Zu0 uXEhm6YB+BpBhO5y2nvjFjCsh2Fd1akUNw3zDJWxACYFOkZItttHbRGbLrQ7wK0UD7fN 9XSQ== X-Gm-Message-State: AJcUukdGV/z9JepsRN9amxE2VzIBBCkeizbxy7CA8FWYqYi6yf5cKVMQ TpbSzrVeWoph+gr7ZN/geVBECf8m X-Google-Smtp-Source: ALg8bN6d/wnSULfCrKnhN/b/WMJn1naB6oswA7phD8rmhxh6od1ldWcD7ZRJhfIP9G2crAHPiHoK1w== X-Received: by 2002:a63:4e15:: with SMTP id c21mr17149907pgb.50.1547376142501; Sun, 13 Jan 2019 02:42:22 -0800 (PST) Return-Path: <12348ung@gmail.com> Received: from [192.168.0.103] ([103.198.24.78]) by smtp.gmail.com with ESMTPSA id y89sm135444573pfa.136.2019.01.13.02.42.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 13 Jan 2019 02:42:21 -0800 (PST) Subject: Re: [FlyRotary] stacked thrust bearing To: Rotary motors in aircraft References: Message-ID: <17e66a62-d945-0a2e-7b13-000216c6af48@gmail.com> Date: Sun, 13 Jan 2019 21:42:17 +1100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/alternative; boundary="------------F84BB65EF135BE845B08DFB1" Content-Language: en-US This is a multi-part message in MIME format. --------------F84BB65EF135BE845B08DFB1 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Steve,                  You appear to have proved what I was coming to suspect, mainly that the gearbox actually fills with oil under load.  Why this happens I cannot say as the drain is possibly 10x the input as per size.  Sure the input is at say 70 psi and restricted to 3 mm or 1/8 inch while the return is gravity at 1/2 inch dia.  I found this while testing when I removed the return line immediately after shut down and got covered in oil which should not have been if it was running on a small amount of oil as it is meant to do.  As usual there is always much to be learned and I thank you for the good information provided. Neil. On 1/13/2019 1:40 PM, Steven W. Boese SBoese@uwyo.edu wrote: > > > Tracy and Neil, > > > In order to prove to myself that the RPM is divided between the > stacked thrust bearings, I installed a Hall effect sensor in the > mounting plate and silver brazed triggers to the middle thrust > washer.  An inductive pickup was installed to monitor the rotation of > the flexplate (input shaft).  This allowed the determination of the > input shaft RPM as well as the middle washer RPM under various > conditions. The load on 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 was possible that the cup > overlapping the 3.5mm shaft side thrust washer would prevent the > middle washer from contacting and causing wear of the input shaft.  > After seeing the results from the used cupped washer, new cupped > washers were obtained and tested also. > > > In the course of testing the thrust bearing 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 the drive > contained about 5 to 6 oz of oil during operation rather than the > about 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.  With the used cupped middle thrust washer, essentially all > the RPM was seen by the mounting plate side bearing.  With the new > cupped middle thrust washer, the RPM  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. > > > My conclusion is that with all new bearing components and unworn shaft > the system behaves as desired.  With used components, the behavior is > unknown.  The cupped thrust washer is not a solution to the shaft wear > issue because of the uneven RPM distribution when submerged in oil and > since shaft wear has resulted from the bearing cages as well as the > middle washer. > > > 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 seal leakage and the seal coming out of its bore.  The > completely oil filled 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.  You are most > welcome to draw your own conclusions. > > > Steve Boese > > > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html --------------F84BB65EF135BE845B08DFB1 Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: 8bit

Steve,

                 You appear to have proved what I was coming to suspect, mainly that the gearbox actually fills with oil under load.  Why this happens I cannot say as the drain is possibly 10x the input as per size.  Sure the input is at say 70 psi and restricted to 3 mm or 1/8 inch while the return is gravity at 1/2 inch dia.  I found this while testing when I removed the return line immediately after shut down and got covered in oil which should not have been if it was running on a small amount of oil as it is meant to do.  As usual there is always much to be learned and I thank you for the good information provided.

Neil.

On 1/13/2019 1:40 PM, Steven W. Boese SBoese@uwyo.edu wrote:


Tracy and Neil,


In order to prove to myself that the RPM is divided between the stacked thrust bearings, I installed a Hall effect sensor in the mounting plate and silver brazed triggers to the middle thrust washer.  An inductive pickup was installed to monitor the rotation of the flexplate (input shaft).  This allowed the determination of the input shaft RPM as well as the middle washer RPM under various conditions. The load on 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 was possible that the cup overlapping the 3.5mm shaft side thrust washer would prevent the middle washer from contacting and causing wear of the input shaft.  After seeing the results from the used cupped washer, new cupped washers were obtained and tested also.


In the course of testing the thrust bearing 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 the drive contained about 5 to 6 oz of oil during operation rather than the about 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.  With the used cupped middle thrust washer, essentially all the RPM was seen by the mounting plate side bearing.  With the new cupped middle thrust washer, the RPM  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.  


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


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 seal leakage and the seal coming out of its bore.  The completely oil filled 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.  You are most welcome to draw your own conclusions.


Steve Boese  



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