torque and temp are definitely important factors with a mag-coupled drive.
it should be pretty obvious from the 1k word substitutes above that torque is irrelevant for a ferro-fluid seal. temps? probably relevant.
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Mag drives can handle torques way bigger than anything i expect a wiped film to require. I guess the real question is what is the cost needed to accomplish that.
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awsome thanks a ton! any idea who the Chinese companies are?
any recommendations??
Nope. I’ve only used mag coupled devices where some other bugger spec’ed the coupler…
…and I’ve only read of ferro-fluid seals.
@Paragon1 made some recommendations upthread.
I’d also tend to agree with @MagisterChemist, the mag couplings I’ve interacted with seemed like they would be up for the task.
I would add that having a torque limit isn’t necessarily a bad thing. saves you from burning out a motor or twisting a wiper into a pretzel.
We recently spun up a mag coupled WFE at my current facility, so I may yet change my mind on that one…
Edit: & hadn’t seen @CollectiveObjective’s thorough response
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if its mag driven I’m assuming its resting inside the main body and not having its physical weight supported on the shaft to the motor, or am I just wrong lol
for a ferrofluid seal, yes, you are incorrect. motor shaft supports wiper.
on a magnetically coupled drive, the weight is supported by the driven shaft bearing.
https://www.vantonpump.com/images/screen%20shot%202017-12-05%20at%20125225.jpg?crc=413877850
(couldn’t find a vertical one in 45 sec…)
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The ferrofluid mechanical seals I was contemplating on using had limitations on rpm. I was using it for a spinning band project using a 4" spool for the body. The band is supposed to spin at 2000-3000 rpm. Not much weight or resistance on a band compared to a wiper I suppose.
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My only experience with ferrofluid (i think is what it was now) wiper baskets was short, not long enough to throughly use/abuse it. Theyre used on a many of smaller wiper systems on the market and seem to be rather low maintenance.
For mechanical seals from SouthKorea, SeoulTech has been the best to deal with from my experience (been a yr) There are alot of traders and mfg supplying out of asia what are essentially copies of the big legacy rotary seal mfg (JC,EB,FS etc) designs. Generally speaking its an old tech compared to ferrofluid seals.
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awsome thanks for the info, it sounds like a ferrofluid is going to work much better than a mag drive or mechanical correct?? any idea if this stays true as you get bigger?
Read the wiki I personally think that they are about as good as it gets
eBay has random ones usually, see if you can score one with a kf fitting
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Hi,
What manufacture is your seal? The ones I have been looking at max out at 80*C, unless you are running cooling water.
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Ferrofluidic
I have a few of em now, might have a diff manufacturer for the smaller ones
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same I haven’t found a non water cooled ferrofluid that’s rated above 100C.
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Any update on how you’ve been liking it? Looks awesome! We’re in the planning stage to tackle building one ourselves. @Rowan