[PSUBS-MAILIST] Dual-purpose fluids

[Sean T. Stevenson via Personal_Submersibles]

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.

Sean


On March 25, 2016 7:09:36 AM MDT, "Sean T. Stevenson via Personal_Submersibles" <personal_submersibles at psubs.org> wrote:
>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.
>
>Automotive motor oil would work for the gears, but is not optimized for
>hydraulic power transmission.
>
>Sean
>
>
>On March 25, 2016 6:29:35 AM MDT, hank pronk via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>>Sean,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.Hank 
>>
>>On Thursday, March 24, 2016 11:15 PM, Sean T. Stevenson via
>>Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>> 
>>
>>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?Sean
>>
>>_______________________________________________
>>Personal_Submersibles mailing list
>>Personal_Submersibles at psubs.org
>>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>>
>>
>>
>>
>>------------------------------------------------------------------------
>>
>>_______________________________________________
>>Personal_Submersibles mailing list
>>Personal_Submersibles at psubs.org
>>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
>
>
>------------------------------------------------------------------------
>
>_______________________________________________
>Personal_Submersibles mailing list
>Personal_Submersibles at psubs.org
>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.whoweb.com/pipermail/personal_submersibles/attachments/20160325/e1adb147/attachment.html>