RE: [PSUBS-MAILIST] hydraulic efficiency questions

[MerlinSub@t-online.de]

No hydraulics in Euronaut - I sold the hydraulid pump I get very cheap short after starting the project. Any matrix I made for main drive, thruster, anchor system etc. shows that hydraulics waste to much of the very limit battery power source the sub has. Its now a full electric design. There are now some very hig performance electric motors on the market. 

Hydraulic is fine for havy workmachines working on mud, ice etc. - and were you have a big source of power..

my fife cent. best regards Carsten 


"Jay K. Jeffries" <bottomgun@mindspring.com> schrieb:
> John,
> 
> It is funny that you should reference that web site.  Have a look at the
> following URL within that site: http://www.allstar.fiu.edu/aero/jay.htm
> Years ago, I was one of the original developers of the web site.at that time
> we built approximately 1200 web pages for aerospace education on the web
> site.
> 
>  
> 
> I agree with you that hydraulics have their applications.  If you work
> through the physics for a 6 HP motor driving a hydraulic system, you will
> only get about 1.8 HP out of the prop after all the losses.  Jet drive
> systems are even more inefficient.  I am sure your system will work but is
> it the most efficient for your money and ease of construction?
> 
>  
> 
> The latest aircraft designs are moving to electrically driven systems
> replacing all hydraulics.  Hydraulics had previously been used for their
> dependability and the linear force that could be developed at a remote
> location.
> 
> R/Jay
> 
>  
> 
> Respectfully,
> 
> Jay K. Jeffries
> 
> Andros Is., Bahamas
> 
>  
> 
> It is the mark of an educated mind to be able to entertain a thought without
> accepting it.
>   -  <http://www.quotationspage.com/quote/1152.html> Aristotle
> 
>  
> 
>  
> 
>  
> 
>  
> 
>   _____  
> 
> From: owner-personal_submersibles@psubs.org
> [mailto:owner-personal_submersibles@psubs.org] On Behalf Of John Gaertner
> Sent: Monday, September 18, 2006 5:20 PM
> To: personal_submersibles@psubs.org
> Subject: Re: [PSUBS-MAILIST] hydraulic efficiency questions
> 
>  
> 
> For those of you who are intersted in hydraulicly driven systems, you might
> want to take a look at the following web site:
> http://www.allstar.fiu.edu/aero/Hydr08.htm  You can learn a great deal about
> the basics of hydraulicly driven systems from this site. From my own
> research, I would personnally say that they can be operated at much more
> efficient levels than has been described recently. I, for one, am designing
> my entire propulsion system around a 6 HP, 24V hydraulicly driven pump
> system. There are a great many valuable resources on the Net about
> hydraulics and their safe, efficient operations. I would encourage folks to
> look further....
> 
> Regards,
> 
> John Gaertner 
> 
>  
> 
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