It's hot , using fans, do they "burn out" ?

[Sarratt]

Thanks for any advise

I have several fans , domestic nothing fancy.

They seem to be all enclosed but can I help their life ?

(one is warm the other not after a full night at lowest power)

One fan seemed to "seize up" within its spinning motor.
?

 

[LukeA]

If it was seized it wouldn't turn even if power was applied. It may be planetary- or wormgear-driven.

The fan that runs hot may just run hot. Leave it on for 12 hrs and see if it's hotter at 12 hrs than at 6 hrs. If it is, I'd replace it because it's not capable of continuous operation. I have a fan that's been on continuously for a week and isn't wny warmer than then it was off.

 

[PhotonWrangler]

If the fan motor uses a sleeve bearing, it eventually seizes due to frictrion chewing up the surface of the metal. An occasional dab of light oil can slow this process down.

Ball bearings are better than sleeve bearings, but they can also dry out so an occasional dab of oil couldn't hurt.

I've seen fans freeze up from gunk accumulating in the motor. I saw one plastic fan that almost caused a fire - it had been running 24/7 for months in a dirty environment, and the constant air flow sucked so much gunk into the motor that the gunk was starting to smolder! I caught it just in time.

In general, keep the motor and fan blades clean and keep the bearings lubricated.

 

[Sub_Umbra]

Both good comments. I would add that we use fans twelve months a year -- for both cooling and heating. Some of the fans we use have bearings covered with a plactic grid which I snip away with a diagonal cutter to make just enough room for the snout of an oil can. I probably extend the life of the fan by a quarter that way -- sometimes much more.

 

[eluminator]

Some bearings are meant to be oiled occasionally. They have a small tube near the bearing. It doesn't take much oil. I guess maybe one drop after a few months of use.

The motor enclosures are apt to have holes that allow air flow. They get plugged with dust. You might be able to suck out the dust with a vacuum cleaner or blow it out with compressed air.

 

[jtr1962]

So long as they're oiled, the induction motors in household fans shouldn't slow down or get overly hot. And if the bearings are never allowed to run dry, the fan should be good for decades. We have some 30 year old fans which still work fine. I think we even had one from the 1930s which belonged to my grandparents. It worked, but we threw it out because it was either rusty or the blades were bent, I forget which.

 

[raggie33]

i have fans die all the time lol i use transions oil to lube em and they seem to go aggain not sure what kinda bearings they have.lol i also wonder if the increased drag will run my power bill up and since fans are so cheap perhaps it is beter to just get new fasn

 

[turbodog]

Having worked for a few years in an electric motor rewinding shop I will add a few things.

Not many bearings are made to be oiled nowdays. That doesn't mean oil won't help them. However, oil helping them and being designed for oiling are two different things. Often, adding oil to a sleeve bearing (typical fan bearing) will help, but it will also attract and hold dirt. Ideally you want to disassemble the fan so you can remove the clean the shaft where it rides on the bearing. If you're REALLY motivated you can swap the bearing from end to end. One end usually wears faster and this will distribute the wear.

I'll never forget this one fan. It was for a grain silo. It ran on 480v 3 phase power. I sat on it when we fired it up. It started skidding across a ROUGH concrete floor. The weeds/trees across the parking lot, across the road, and in the ditch (probably 100' away) started whipping around as if blown by tornado-force winds.

When you oil these things, you don't want oil running out. That's just asking for dust problems. Just add enough where it is still being pulled into the bearing area, and stop before it fills up. Allow it to soak/wick into the bearing before running the motor.

 

[greenstuffs]

I just know that if my fan dies i go walmart and buy another one for $8 pretty cheap compared to flashlights or batteries . My computer fan has been running 4 yrs now 24/7

 

[Sarratt]

Thanks for all the advise.

I've also edited my original post to one with correct spelling and grammar.

I have "rescued" 2 fans from my neighbours who said they stopped running. One I cleaned but the other was rock solid in its turning thingie (motor)

Turbodog ... your explanation is kinda confusing. It's a domestic fan. Not an Industrial windblower lol

As an aside .... Teflon Spray ...hmmm
I just found a spraycan of it ( evidently at some point I needed it-- darned memory)
Could I use it?

 

[will]

This is a repeat of some of the other posts - Most inexpensive fans have a sleeve type bearing. These will usually get gunked up after a period of time. I will unplug the fan and take it completely apart. The armature shaft will usually have some gunk on it, so will the inside of the sleeve bearing. clean these up and put a few drops of a light weight oil on the bearing. Most sleeve bearings are made of sintered bronze, which actually holds oil, the spinning of the shaft will draw the oil between the shaft and the bearing.

 

[jrmcferren]

The most common failure mode that I've seen in AC powered fans is that the motor becomes sluggish with extended use on poor power and upside down (clip on type). When this happens turning the fan right side up increases speed, but still too sluggish. Another failure mode I have encountered is that sometimes I need to stick a finger (pencil, pen, etc for those that are afraid or are dealing with metal blades) through the grill (one piece moves) and start it manually, but is still reliable and I have used it for a few years that way.

Another fan I have the one motor screw gets almost hot enough to burn your finger but never any hotter, it works great and came from the factory that way.

My newest fan is an O2 Cool; AC, Rechargeable, and D-Cell fan and it uses PWM for speed control.

 

[Sub_Umbra]

...Another failure mode I have encountered is that sometimes I need to stick a finger (pencil, pen, etc for those that are afraid or are dealing with metal blades) through the grill (one piece moves) and start it manually, but is still reliable and I have used it for a few years that way...

Many of my fans become hard to start later in their lives. I started many fans with a chopstick until it occured to me one day that I could just put it in front of another fan and Blow Start it.

It works well. I got the idea from Chuck Yeager's Autobiography where he tells a story about starting a jet engine with another jet.

 

[eluminator]

It seems to me the small fans that have a hard time starting have dirty sticky viscous oil in the bearings. I think I once fixed one by taking it apart, cleaning the bearing, and putting a little low viscosity oil on it.

These fan motors have very little torque when they are stalled, and a little increase of the friction in the bearings prevents them from starting.

One thing about a fan is it takes virtually no torque to turn it slowly, and so the small cheap motors with low starting torque can get them going. Until the oil in the bearings gets dirty, that is.

Or maybe it's just my imagination

I don't have a good suggestion for low viscosity oil though, but there must be some around. I use KleanHeat, but I suppose most of you burn something else in your kerosene lanterns, and don't want to order a gallon to fix your fan

 

[Minjin]

I've been using Militec-1 in my fans because of the precision oiler it came with. No idea if it helps. One of them started making occaisional bearing noises shortly after being lubed but it was probably just a coincidence.

 

[Sarratt]

planetary- or wormgear-driven.


shaddup and tell me to oil it .

I'm sorry I asked such a doofus question.