<html><head></head><body><p dir="ltr">I am considering a ducted thruster design driven by a hydraulic motor perpendicular to the duct axis, with a compact miter gearbox in the flow path within the duct (in an appropriately faired housing) with two output shafts rotating in opposite directions. The two counter rotating propellors would null the helical flow from the thruster. My idea was to run the hydraulic oil on the output side of the motor (@ tank / compensation pressure) through the gearbox (with sufficiently large flow path to minimize restriction / upstream pressure) before returning to tank, to lubricate the gears with active circulation so that wear particles can be filtered out, and the gear housing would be pressure compensated that way. It's all a bit complicated, but with spiral miter gears the efficiency loss shouldn't be that bad, and there are other advantages to hydraulic drive.</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On March 25, 2016 7:09:36 AM MDT, "Sean T. Stevenson via Personal_Submersibles" <personal_submersibles@psubs.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<p dir="ltr">I've been doing a bit more research online. It looks like a hydraulic fluid with anti-wear additives will work, but I might need to go to a higher viscosity grade than would be strictly ideal for low-loss power transmission. I'll have to do a bunch of calculations to see how much of an efficiency hit that will be, but there are big advantages to using the same fluid for both.</p>
<p dir="ltr">Automotive motor oil would work for the gears, but is not optimized for hydraulic power transmission.</p>
<p dir="ltr">Sean<br />
</p>
<br /><br /><div class="gmail_quote">On March 25, 2016 6:29:35 AM MDT, hank pronk via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div id="yui_3_16_0_ym18_1_1458908775440_2672"><span>Sean,</span></div><div id="yui_3_16_0_ym18_1_1458908775440_2672" dir="ltr"><span id="yui_3_16_0_ym18_1_1458908775440_2778">I use motor oil for hydraulic fluid all the time. I have a small 1\2 hp right angle gear box here that uses motor oil in it. I think it would depend on the load on the gear box.</span></div><div id="yui_3_16_0_ym18_1_1458908775440_2672" dir="ltr"><span>Hank</span></div> <div class="qtdSeparateBR"><br /><br /></div><div class="yahoo_quoted" style="display: block;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div dir="ltr"><font size="2" face="Arial"> !
On
Thursday, March 24, 2016 11:15 PM, Sean T. Stevenson via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br /></font></div> <br /><br /> <div class="y_msg_container"><div id="yiv8168812609"><div dir="ltr">I want to know if there is such a thing as a fluid which is simultaneously suitable for hydraulic power transmission (piston pump / motor) and as a lubricant fill (circulated) in a custom bevel gearcase?</div>
<div dir="ltr">Sean<br />
</div>
</div><br />_______________________________________________<br />Personal_Submersibles mailing list<br /><a ymailto="mailto:Personal_Submersibles@psubs.org" href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br /><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles" target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br /><br /><br /></div> </div> </div> </div></div><p style="margin-top: 2.5em; margin-bottom: 1em; border-bottom: 1px solid #000"></p><pre class="k9mail"><hr /><br />Personal_Submersibles mailing list<br />Personal_Submersibles@psubs.org<br /><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br /></pre></blockquote></div><p style="margin-top: 2.5em; margin-bottom: 1em; border-bottom: 1px solid #000"></p><pre class="k9mail"><hr /><br />Personal_Submersibles mailing list<br
/>Personal_Submersibles@psubs.org<br /><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br /></pre></blockquote></div></body></html>