Hello,
I find this a very interesting product:
It claims that it's fans "levitate".
Does this mean it no longer requires any oil and thus no more cleaning because of dust+oil+black smoke stuff frictions ?
I consider this a major breakthrough, now PCs won't require any more oil to function.
Perhaps oil to produce them, but after that, no more oil needed LOL.
Such a re-assurance ! Really it's very nice to know. In case the oil runs out some day ! LOL.
Bye, Skybuck.
The OEM is likely to be Sunon.
See page 3. The design relies on magnetic attraction. There is still a bearing.
Now if you look at this diagram and page, you'll see that the claims are slightly different. The fan actually has more conventional elements to it. The fan is not quite as magical as it looks in the Sunon PDF.
(
"Prevents dust penetration, increases lubrication circulation"
From another web page
"The unique feature of SUNON's MagLev motor fan is that the path of the flan blades during operation is magnetically controlled by Sunon's patented MagLev System. The result is that the shaft and bearing have no direct contact during operation and so experience no friction no matter how the fan is oriented. This means that the characteristic abrasion noises of worn-out components are not produced and also allows a service life of 50,000 hours or even longer at room temperature. "
Some fans at work had a service life of 25000 hours. We would tell customers to do a preventative replacement of the fans in the product, every three years of 24 hour per day system operation (the fans could be replaced with the power still on). These Sunon fans would be good for six years, if you believe the advertising material.
The device is not a fluid dynamic bearing, and isn't sealed on the ends. It just has dust caps. Your guess is as good as mine, as to what the lubrication circulation pattern looks like.
The Panaflo fans, used a sealed bearing with a trade name of "hydro wave". Which I believe is a fluid dynamic bearing. Rather than a dust cap, that's an attempt at a sealed bearing. While I don't have a datasheet (and Panaflo was bought by NMB), a quick Google lists some of those fans as having a 50000 hour service life.
So if I held two fans in my hand, a Panaflo and a Sunon Maglev, which would you buy ? :-) Which has the least flaky explanation for how it works ? You decide. The Sunon looks like it has a pretty conventional bearing. And when real world considerations are taken into account, the bearing will not be exactly frictionless. It will be "close to" frictionless.
HTH, Paul
gpu,31977.html
I've been designing Sunon maglev fans into rackmount comms products for years. I could check with production here, but off the top of my head, I don't think we've had a single field failure (vs a lot of field failures for the cheap sleeve bearing fans that we used in earlier designs).
Caveat: Until the fans "fly" they are just like crappier-than-normal sleeve bearings. Expect lots of wear below a minimum RPM (that I don't think is specified in the datasheet, although they may specify a minimum voltage or PWM duty cycle). Start and stop cycles will also cause wear.
So be careful about your thermal management software - you might need to disable some of the software features that slow the fans right down or turn them on and off cyclically. Those are features you want for a sleeve or ball bearing fan, but not for a maglev fan.
Regards, Allan
How do you guarantee it to spin at maximum speed?
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Do not reduce the PWM below the recommended minimum. Or do not reduce the voltage below the recommended minimum.
The fan that the OP linked actually specifies an RPM range (400 - 2400), so it would be acceptable to reduce the PWM duty cycle as long as the speed is above 400RPM.
Regards, Allan
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