Ceramic pump shafts?
 

Hello again everyone, at AVT we just received ceramic pump shafts for an OEM special pump.

They also happen to fit C-Systems MAG units and I was wondering if there is any interest in using this material in liquid cooling. Our senior engineer say this material will have little effect on bearing life, so there is no engineering concerns using it.

I was just thinking some of you may have some chemical reason too use this material over stainless steel?

Just an idea since I now have access to them.

Dave

EDIT
I misunderstood the app
comments retracted

I have ceramic bearings on the deraileur sprockets on my bike and have seen no wear after hundreds of miles, no lubrication. I cant say traditional bearings have lasted this long on my bike, even though this is a completely different situation than a water loop.

My mag 3 has been running for years now, no play on the impellor shaft as of yet, still very smooth and round. The impellor seems to have no wear either. I'd say it is safe to say that ceramics are the way to go.

Looks like I started a good arguement at work :)

Dan is convinced both our engineer and the customer are mistaken in using this material.

He believes the large grain structure of the ceramic material will cause micro fractures in the sapphire bearings, which intern will result in increased wear.

On there side, they believe the bearing and shaft will form a proper wear surface and run on fluid as designed. They now have me setting up a 30-60 day trail.

Will let you know what I find.

Dave

ah, sorry
did not realise you were going to run sapphire on ceramic
previous comments withdrawn

^Why?
I have been researching the issue all morning, and they both can be right.
I found examples to support both arguements.

Test, test, test and test again :)

agreed, but outside of my actual experience

I would speculate that if the ceramic finish is adequate then the film will do its job
and the shaft could be grooved for greater flow - depends on the tolerance stack in part

some delicate wear measurements coming

Not a big deal as we have a really good scope and optical comparator.

You did have a good point about dyes and substance buildup.
I have strongly suggested to C-System they make it very clear on the new WEB site, using unknown substances in fluid will void warranty.

I am setting up ceramic on sapphire, and ceramic on ceramic tests to compare against old data for stainless on sapphire.

I've seen ceramic shaft in magnetic pumps (used at Film Processors). The advantage is not be affected by Developer/Fixer Chemicals. But it's used on plastic bearings, not sapphire or stainless steel.

I'm not sure a warning on the web site is strong enough. Maybe a prominent sticker? Not that all your users will read that either (ask BillA how well a "do not run dry" sticker works) - but it's got to be better than a web site disclaimer.
Too bad there isn't the pump-equivalent to those exposed-to-too-many-Gs devices...

Ceramic on sapphire, bad idea just as Dan suggested.
Came in this morning and test pump is making noise.

Ceramic on Ceramic is fine, but the sapphire on stainless still produces the least noise.

Should be an interesting monday morning this week.

Dave

**These are special test pumps designed to load bearings 400% of norm, and have an offset magnetic pattern.