This is a low speed ( 200 RPM ) pillow block bearing operating in a very dusty environment.

The idea is to prevent dust ingress by keeping the pillow block cavity completely full with grease utilizing high pressure automatic grease lubricator. Moreover, even expelling grease at a low rate outside by keeping positive pressure inside the bearing.

Any experience on that?

Thanks,
David

Per the bearing manufacturers, you shouldnt let the housing get full (should repack before you get to that point).

I have a concern about filling the cavity full, but it is less a concern for slow speed machine like yours since low D*N bearings are more tolerant of full housing than high D*N bearings.

You are trying to address poor reliability due to contamination. I think it will solve that problem and the probability of introducing a new problem (based on full cavity) is low in your slow-speed application.

David, have you come up with a solution yet?

You don't say what size the bearing is, but for a bearing that slow, filling the housing with grease should not be a problem and might be enough to keep the dirt out. What kind of seals are you using? SKF makes a Taconite seal that is a grease sealed labyrinth and would be very good at keeping the dust out. There is also a version that has a seal in the labyrinth. I haven't tried them yet since my dusty application is at 1800 rpm and these will not work at that speed.

Click on this link to see a picture of it.

http://www.skf.com/portal/skf/...ang=en&newlink=2_1_5

Have not come up with any solutions. The bearings have not failed in the past few months, so why spend money . Familiar scenario...

SKF solution sounds good, but is there any experience?

We used Cooper Split bearings on hammer mills that had a grease seal. It was very effective. It was dusty to the point that the lower half of the bearing housing would get covered. Grease seal created a barrier.