RE: (ET) DC hydraulic pumps [Virus checked]

["Pieter Litchfield" <plitch attglobal net>]

Thanks very much for the link - here's a happy co-incidence - they have an
actuator called an "Electrak."
I note that there are 36 volt long stroke heavy lifitng actuators listed
there that would be ideal!

-----Original Message-----
From: owner-elec-trak cosmos phy tufts edu
[mailto:owner-elec-trak cosmos phy tufts edu]On Behalf Of Dave Reuter
Sent: Monday, May 12, 2003 12:13 PM
To: Pieter Litchfield
Cc: elec-trak cosmos phy tufts edu
Subject: Re: (ET) DC hydraulic pumps [Virus checked]



Pieter,

If you use a screw nut and not a ball nut the screw nut will hold due to
the friction in the interface between the thread of the nut and screw. When
I used it in that application I mentioned I would load up the screw to the
3000 lbs and leave it for hours in this position and it held fine without
power. The only disadvantage is that it is less efficient and you have to
power it down as well as up. But it still will be better than all the
losses due to energy conversions that you described in your email between
the battery, the electric motor, the hydraulic motor, and the cylinder.

A company I worked for in the past was Warner Electric. They were sold to
from what it looks like from a internet search Danaher.

Here is a link to the product line for actuators. Hope this helps. There
seems to be a few people interested so I'll post this to the group.

http://www.thomsonindustries.com/Sections/products/products_main.asp?PC=8999
003&L=False&IT=Contact&GI=1



Dave Reuter