Regarding the high temp requirements w/NEMA 4 rating . . . I failed to mention that the ballscrew app discussed in my earlier post is subject to ambient temps in the range of 100 deg C with continuous water spray in the area. The motor is covered with a shroud to deflect 95% of the water, but steam and high temps are very much a part of the environment as well as the occasional blob of molten glass. . . . all wiring is water proof stainless braid flex with sealtite connectors. Most common mode of failure is when an inattentive operator allows a glass dam to
form and melts the motor leads together within the flex conduit.

Ken Brown

Applied Motion Systems, Inc.

http://www.kinemation.com
Voice 360 686 1133
Fax 360 686 1166

 

David,

For a "headless" transducer, try Temposonics
http://www.temposonics.com/tempohome.html
I know they were working on at one point, I'm not
sure how far away the head can be located though.

If you are looking for an absolute encoder, try www.ivo.de, they have a multi-turn you can program
for number of turns,ppr, etc.

Perhaps a hollow shaft encoder can mount directly on an unused section of the screw ?

Peter

 

One solution is to use a fine/medium resolver system. These are used, for example on storage/retrieval systems were they have the
same challenge.

The feedback device consists of a gearbox with one or more resolvers so the course resolver makes only one revolution for the entire stroke. Higher resolution is accomplished in the same device with a second encoder at a lower gearbox reduction.

I would check with Thompson/Micron for more information
www.thompsonindustries.com

 

Most Doppler devices I've looked at have a minimum speed at which they will work. This has to do with the ability to discern the small phase shift at low speeds.

Anthony Kerstens P.Eng.

 

Sorry, I don't remember original basis for this thread, but:

If hi-temp wirng was involved, investigate type MI (Mineral-Insulated). The more common sheath materals are Cu, Al, & SS. Temperature ratings
(except for terminations) approach the sheath melting temperature.

Regards,
Phil Corso, PE
Trip-A-Larm Corp
(Deerfield Beach, FL)

 

There's also a new linear motor, by Cal Linear... 500lbs force that's a cylinderical linear... it might allow you to keep the windings out of the hew, although they have experimented with waterjacket... If you want I can put you in touch with their engineering.

Bob Close
PMC