The bearing has serviced in wet area so corrosion generated,what type of grease can improve this.

Thanks.
Phoo

Bearing_Corrosion.ppt (118 KB, 44 downloads)

I would think of improving mechanical sealing capabilities as well. If it were a deep groove bearing, I would have suggested looking at sealed or shielded beairngs, depending on the speed. But that's not an option for these spherical roller bearings. Still there might be opportunities to improve sealing - various kinds of lip seals, Forsheda V ring, etc. Perhaps even Inpro seal.

Various lube manufacturer's literature will make claims about water resistance. Here is one I just found on google:
http://www.americansyntheticoi...il-water-grease.html

Now it's interesting that they use Lithium complex thickener for the above water resistant grease. I have looked at Lithium complex thickener vs shear stabilized polyurea thickener grease from another manufacturer (Mobil Mobilith vs Polyrex) and that manufacturer considers the one with the shear stabilized polyurea thickener to be more "water resistant" than the one with the lithium complex thickener. I think there was an Amsoil rep on the board, maybe they can explain why that is.

There are some tests from ASTM that perhaps allow some objective comparisons:
ASTM D1264 - water washout - does it flush out of bearing when sprayed with water
ASTM D4049 - water washout - does it ahdere to steel surfaces when sprayed with water.

Also the base oil may have a rating for corrosion resistance based on ASTM D665, ASTM D1748, ASTM D3603, ASTM D6557. But I tend to think the water washout would be more important than the corrosion resistance of the base oil.

It seems like it would be useful to have a standard test for resistance to chemical degradation of the grease itself in the presence of water (vs washout which is more of a mechanical effect). I am not aware of such a test (has anyone heard of one?)

Of course, selecting grease is not a one-dimensional problem. Need to consider speed, size, horizontal/vertical, load, temeprature etc. As an overall strategy, I think most people select one brand (such as Exxon/Mobil), and then ask the rep or application engineer to help you choose which will is best suited to the particular application from his offerings within that brand.

This message has been edited. Last edited by: electricpete,

Pete
Thanks for your opion, I will consider. addition attached detail of bering housing.

Phoo.

Hi Phoo,

I think a Aluminium Complex thickner will do a great job.Please tell me more about the aplication or send me an email.I'm sure I can recomand 3-4 products(depends on the aplication).

regards