[PSUBS-MAILIST] bow thruster

[Sean T. Stevenson via Personal_Submersibles]

The counter rotation is a function of the design of the gearbox. It is possible to do it either way, but having e.g. one right handed prop on the forward shaft and one left handed prop rotating in the other direction on the after shaft counters wasted energy from discharge thrust that is circumferentially accelerated. Of course, there is some wasted energy associated with the gearbox, so it's not all positive, but I think I'll come out ahead in my specific application.

I wasn't going to vector one big thruster through a large range of motion, but rather have thrusters mounted on either side, with some degree of movement in order to selectively optimize the thrust direction depending on commanded ahead/astern, lateral, or rotary movement.

Any such scheme has to carry all of the thrust through to the vessel, so it requires some thought on how to best arrange.

Sean


On March 25, 2016 8:36:11 PM MDT, hank pronk via Personal_Submersibles <personal_submersibles at psubs.org> wrote:
>Autorotate, maybe wrong word, I meant both props turn opposite
>directions.  Are you thinking of vectoring in multiple directions or
>rotating 360 degrees.I was once working on a single thruster design.
> The thruster could point in any direction so the sub only needs one
>thruster.  Hank 
>
>On Friday, March 25, 2016 5:12 PM, Sean T. Stevenson via
>Personal_Submersibles <personal_submersibles at psubs.org> wrote:
> 
>
>It will be similar to a surface vessel bow thruster, only instead of a
>thruster tunnel in a hull, it will be housed in a symmetric nozzle
>which itself can be vectored with an actuator.  I'm designing the
>gearbox from scratch - a few off-the-shelf spiral miter gears, tapered
>roller combined load bearings, shafts, seals and ports for oil
>circulation. Not sure what you mean by autorotate? They will not
>freewheel, if that's what you mean. Zero output on the hydraulic
>servovalve will lock off fluid flow (and thus lock out motion),
>although the gearbox will still be pressure compensated from the
>discharge side.Sean
>
>On March 25, 2016 3:59:31 PM MDT, hank pronk via Personal_Submersibles
><personal_submersibles at psubs.org> wrote:
>Hi Sean,It sounds like you are going for something like a hydraulic bow
>thruster, I am not sure if the props autorotate.Hank
>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/bca4567f/attachment.html>