Hellow Everybody
I have a problem about Acid Scrubber Fan by we got high temperature at bearing (Pillow Block Type 39243DE, 1500 rpm. ). Now temperaure about 45-50 C but we cooling all time by air from air compressure. The future we want to not use air cooling .If everone have a suggession please inform me.

Thank You

You did not mention what was the temperature before cooling with compressed air?
Regards
Irshad

I don’t know about others, but most of my scrubber fan bearings run hotter than the temps you mentioned. As Akhtar asked, What are the temps with out cooling air? Is the unit a belt driven one? Which bearing is hotter or are they the same?

Some items to check are: Too much grease or belts too tight or both bearings held (one should be an expansion bearing) Or they may be ok. I do not get concerned until my bearings get above 75-80 C.

Gary B

I agree with Gary. The temps aren't high and the most common reason I find for higher than normal temps is overgreasing. You also don't mention what the ambient temperature is.

Air cooling is very expensive and can cause problems depending on the source of the heating. If the heat is being transferred through the shaft into the bearing, cooling the bearing from the outside can create some real problems. In that case, it would make more sense to cool the shaft rather than the bearing.

First, determine if there really is an abnormality, then find and treat the cause. Also, I would suggest the addition of vibration analysis if you aren't already using it. Temperature is an unreliable measure of bearing condition in my opinion. It can tell you some things and is a good parameter to track, but it's use for bearing diagnostics is very limited.

Dear All
Thank you for any suggession. For maore detail I wil summary and post it soon.

Thank you very much.
Ekkach

Hello Ekkach,

There are many kinds of causing bearing overheating .
It's may about 53 kinds , and the vibration analyzer is good tool to know what happened in bearing.

The misalignment bearing assembly is one of the causing bearing overheating.

Hello guy.
Data for analy are.
1. Ambient Temp = 30 - 33 c
2. Temp before Cooling by air = 80-85 c
3. Temp After Cooling by air = 40-50 c
4. Temp. of Shaft = 35-40 c
5. Vibration data in attach file

Thank You Very much
Ekk

Scrubber.xls (72 Kb, 3 downloads)

Is that a tapered roller bearing? A search on that part number comes up with a Timken tapered roller bearing.

Are you grease or oil lubricating the bearing?

Dear mbensema
For type of Bearing Now we used EARING 22215EK WITH ADAPTOR SLEEVE#H315 (SKF) and BEARING TIMKEN TYPE 39243 DEE/39415X (TIMKEN). But we find high tempertaure both brand.
For lubrication is grease type MOBILUX EP2.

Thank you very much.
Ekk

No lube expert here, but EP2 seems pretty heavy to me.

Have you checked to make sure that tis is the proper lubrication method? Are you certain that over-greasing is not occurring?

The most common cause of high temperatures is incorrect grease or overgreasing as Danny already mentioned. If your ambient temperature is high, then the bearings will run hotter as well and you will need to select a grease suitable for the higher temperatures.

For a bearing that size and running speed, the Mobilux EP2 looks like an acceptable choice, but unless the load is high, a grease without EP additives can be used as well. It has a viscosity of 160 and at your higher temperature is actually a bit low on the viscosity and a viscosity of 220 would be a bit better. A viscosity index of 2 to 4 is ideal for long life and your uncooled conditions give about 1.8 Before changing the grease, you need to check all the operating conditions to make sure you are selecting the correct one, but I don't see anything wrong with your choice based on the info provided. The Mobilux EP2 is rated for temperatures up to 130C, so I would not be too worried about running at 85C unless you are having frequent failures.

As far as looking for ways to reduce the temperature, I would start checking to make sure you are not overgreasing the bearing, check to make sure the housing is not overfilled (it should be about 1/3 full) and that the grease drain is open. A bearing will run hot for a few hours after greasing, if the bearing is being greased often, that could be your cause. For the spherical bearing, I would check to make sure your clearance is correct after mounting on the sleeve. If you reduce the clearance too much, you could get higher temperatures. It could be that this bearing is highly loaded or misaligned which will result in higher temperatures as well.