I have a motor generator set that rotates at 1800 rpm. the flywheel bearings show a haystack in the vibration data at 4kHz (indicates not optimum lube boundary). The flywheel weighs 800#. The bearings are SKF SNR 6316. We are using Mobilith SHC 100 grease in these right now. I am considering EP-2 grease instead due to the heavy load. They make an audible squealing sound. They have run like this for a long time without failure. These are not self aligning bearings so it may be that there is no grease that will help.

any thoughts?

thank you

Joe

You might look at this one by EXXON
http://www.exxon.com/USA-English/Lubes/PDS/NAUSE2GRSEXR...xtra_Duty_Moly_2.asp
Used on Heavy mining and lumber mill flywheel systems.
Also go here
www.huskey.com
(norco Calif)
Talk to thier engineer. I believe they can put together a synthetic with polymers that may help in this also. Custom problems require custom answers.

Hi Joe,

You said "They have run like this for a long time without failure"
We would be inclind to check the used grease visually by Wear Debris Analysis or Ferrogram, that way we will be able to check whether the squealing and VA readings are actual damage,
if the used grease has no significant wear debris then the need for change reduces,
check the dN value of the bearing and grease if changing from the SCH 100 the EP 2 as this could increase the base oil viscosity of the grease from ISO 100 to ISO 220 depending upon the grease and may cause an increase in temperature,

Regards Rob S

rttech.com.au

We have the same !!!!!! machine as you guys. GE Mg Set with the flywheel on the AC motor end. We use AW-2 grease and monitor with acoustics. It pretty much always sounds noisy but we have managed to keep it below the threshold of concern. We have 6318 bearings in the motor flywheel end with a 6314 in the other end. As far as vibes we only take a 2000Hz spectrum in IPS so we don't see beyond that, however we do see a small haystack in G's about 4000HZ.
Let me know if you need any additional information.

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

Can you guies look at a grease with solids and base oil viscosity of 460 or a Ca Sulfonate grease with base oil viscosity of 460

Great machines-GE RPS Mg Sets I presume. We've battled bearing/flywheel noise for years on these machines. We monitor the grease application with acoustics to prevent over/under greasing. We use Mobil AW2 grease. As far as I know the bearings and pillowblock housings are a special GE design which makes keeping grease in the bearings difficult if there is any wear. Contact me for the details on our bearing replacement evolution.

If I had to suggest a grease to fill your needs I would suggest Texas Refinery Corp.'s Paragon 3000 . A superb grease with a Timken OK load rating of 100 in the EP# 2 grease and a ultra high droping point of 630 deg F. If your looking for a good Moly grease I would suggest their Moly 880 Crown and Chassis Grease. Another great problem so**er grease with a high Timken OK load rating. It however has a lower droping point.

Hi Joe
I think we probably sell tons of heavy load and shock load greases to various customers in steel, cement and mining industries. Our experience with Molykote Longterm 2+, a mos2 based product is extremely good. However the DN value is about 250000 (rpm x avg dia of the bearing). I am not sure Dow Corning sells that in US or not. Check for a good moly grease available in your region and try that. They should take care of your squealing and also provide emergency lubrication for some time before you replenish.