Difference between double bearing, single, and sleave bearing fans?

Is the only difference in how long they fan last? (Beside the point that sleave bearing is the cheapest)

That's the primary difference. Also, as I understand it, sleeve fans can be a bit quieter than ball-bearing fans. (I've never used a sleeve fan myself.) -- Paul

Supposedly they start quieter but get louder over time, while ball bearing fans keep the same noise level.

The ball bearings can also get louder as they wear, AFAIK, as far as I've observed ... -- Paul

Sleeve bearings are really dependant on the material. So cheap fans use cheap sleeve bearings, mid price -> high rpm fans use ball bearings, and some high end quiet fans use high quality sleeve bearings. I only use Papst fans, those have sleeve bearings.

All fans should have a longer life if you oil them before they are due for an oiling. This means, you don't wait until the fans start making sctraching noises (indication that they need oilling) before you oil them.

This will also ensure they remain at their minimum noise level and give best performance.

Please remind me -- this is where you peel up the sticker a little and find the oil hole? What type of oil? WD-40?

Thanks! -- Paul

Yes, if you peel the sticker back, you should find the hole for the shaft. On 60mm and smaller fans, the hole iis directly behind the sticker. While on larger fans, eg 80mm, it is usually covered by a little lid which is fairly easy to remove.

The hole is where the shaft construction is and if your fan is a ball bearing fan, you will see the bearings there. If not, you won't see much except the metal shaft of the fan.

DO NOT use WD 40 or similar oils as these are not good lubricants. They will last about as long as water when used in a fan that is spinning at 2000rpm. Instead, use any sort of light oil such as 3-In-One or sewing machine oil.

Don't fill the well up with oil. Just add a few small drops while at the same time spinning the fan with your fingers. This will ensure the oil seeps down into the shaft and covers it nicely.

Prevention is better than cure!

thanks for the tip! maybe I'll get around to that sometime ... -- Paul

sleeve fans tend to wear out fast due to oil vaporization since the unit is not sealed. Some fan manufactures come out with more advanced sleeve fan which prevent oil from drying up and also use certain mechanism pumping oil to keep the rotate part fresh.

From I heard, these new type of sleeve bearing fan actually last longer than single ball bearing fan, but still fall short of dual ball bearing fan in MTBF.

Interesting post.

Hmm, but if a MTBF is "only" 40,000 hours = 4.68 years, and it's quieter than a ball-bear fan, then it sounds like a good way to go!

Actually, I noticed that on my Tt fan box, they listed two models: one with ball bearings and a MTBF of 50,000 hours, and another a sleeve unit with MTBF of 30,000 hours = 3.5 years. That's still a pretty long lifetime ... I might start looking more towards the sleeve variety ....

-- Paul

50,000 hr are pretty much marketing hype. Most of taiwanese fan manufactures start to list such high number hoping to jack up their quality image.

So far I only found one Taiwanese fan manufacture, Delta Electronics who do NOT BS the MTBF number.

D'oh, I forgot to welcome you to the forums!

Indeed, you do always need to take such numbers with a grain of salt ... good points -- Paul

Well I was looking at the same model fan(same output,noise level) that was available in sleave and ball bearing. I just baught one of each