Newsgroups: comp.robotics
Path: brunix!sgiblab!sdd.hp.com!decwrl!netcomsv!netcom.com!nagle
From: nagle@netcom.com (John Nagle)
Subject: Re: robotic hydraulics infomation resources.
Message-ID: <nagleC52oq4.L99@netcom.com>
Keywords: hydraulics, robotics.
Organization: NETCOM On-line Communication Services (408 241-9760 guest)
References: <1phk6jINNbgo@uk-news.uk.sun.com> <1993Apr5.214644.16672@phx.mcd.mot.com>
Date: Tue, 6 Apr 1993 17:32:28 GMT
Lines: 22

schuch@phx.mcd.mot.com (John Schuch) writes:
>"Hydraulics" and "small robots" are not usually used in the same
>sentence. Or you have a different perception of 'small.'

      To some extent this is true.  Early hydraulic robots were bulky.
But some recent efforts on teleoperators use hydraulics in the arms and
fingers, that being the best way to get human strength levels in human
sized teleoperator arms (work at Hawaii?)

      Still, to do hydraulics work you need good support facilities,
including a machine shop and people who know how to use it.  

      Incidentally, hydraulic systems don't leak if properly designed.
I used to work at a hydraulics R&D facility (Sperry Vickers) and 
even the experimental stuff didn't leak.  Construction equipment
hydraulics doesn't leak unless both badly abused and badly maintained.
But some hydraulic robot plumbing does leak, generally because the
designers actually thought steel was rigid.  Hydraulic systems have
energy densities high enough you can't make that assumption.  Everything
is a spring.

					John Nagle
