cold temp gearbox bearing lube schemes?

[pwarila]

We have had some trouble with bearing failure in speed-increasing gearboxes in wind turbines. I suspect the lubrication setup. At times these boxes may be sitting idle all night at 0 or 10 deg F, then the wind comes up rather abruptly and the box needs to transfer 800 hp with very little warmup.

Can anyone recommend info sources on lube schemes for such environments?

Thanks much!

 

[ischgl99]

I ran a test machine on a tractor trailer flatbed that would sit overnight and then be needed to test in the morning. We had problems with the oil pump kicking out on overload due to the cold oil. When we switched to synthetic oil, problems were reduced. Another solution would be to add a heater to the oil tank, if you have one, if not, maybe you would want to think about a forced oil lubrication where you can heat the tank on the cold nights. Mike Bensema

http://www.dutchmenservices.com

 

[MASSEY]

Good bearing greases are rated generally from -30F to 225F.
If your bearings are failing due to cold temps. I would suspect faulty seals permitting moisture into the bearing assemblies.

If moisture is allowed in, there is a lot of room in a normal bearing assembly for water to sit and freeze enough to distort a bearing cage subjected to sudden torque.

Cold lubes can be purchased obviously, from places such as Dow and others. We use them at customer requests, but standard EP lube would usually work just as well.

Usually moisture isn't that big of a deal in bearing assemblies, you can get coatings such as AquaSpex from Timken to deal with that. The problem would be if there was enough moisture to actually freeze solid so the cone was not allowed to freely rotate on the cup.