- Joined
- Jan 28, 2011
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- 3,484
We have a rolling mill that is our main machine. 90% of our product starts at the machine. We purchased it used and had it modified and rebuilt at that time. That was 15 yrs ago.
Over the last few years there has been a clunk sound coming out of the drive section. So couple years ago I took it apart and saw that the sleeve bearings were worn out, actually damaged, and the driver journals as well. My plan of attack was to have new sleeve bearings made with a smaller ID and to grind the journals to match the new smaller size and thus clean up, renew, the journals. These bearings are of a size that the material is not cheap. 3 of them are 4" long and just under 3" OD and 2.5" ID. The forth is longer about 7" but same OD/ID.
As this machine is used ALL THE TIME, we waited until the time was right. Well yesterday was the day. In the afternoon I tore it down and today the drivers were setup in the lathe to remove about .030" of junk surface and minimize the time on the universal grinder. While that was happening I pressed out the old bearings and installed the new bearings after the grease holes and channels were cut in. By 3 pm today the rolling mill was up and running, with new bearings, lube system for the rest of the machine flushed, lube filter changed and the new bearings greased and buttoned up.
The damage was the same for ALL the bearings. I would not expect that all would have gone bad due to poor maintaince and in fact we hit the grease fittings every 2 months, the RPM is only 2 to 5 and grease works well for this application. I believe that in the past prior to our buying the mill that the damage was caused by poor thinking. The machine is old enough that I think someone decided to change from oil lube for the bearings to grease. He removed oil feed tubes and threaded the holes for grease fittings. The chips were not cleared and the pictures show what the result was.
Note that the machine was to have been rebuilt by the vender. This I firmly doubt as so does the owner.
I thought you may like to see what the old bearings looked like. This is 1 of 4 and they all look the same. I added a picture of a small rolling mill and the arrow is pointing to where the drivers live.
Over the last few years there has been a clunk sound coming out of the drive section. So couple years ago I took it apart and saw that the sleeve bearings were worn out, actually damaged, and the driver journals as well. My plan of attack was to have new sleeve bearings made with a smaller ID and to grind the journals to match the new smaller size and thus clean up, renew, the journals. These bearings are of a size that the material is not cheap. 3 of them are 4" long and just under 3" OD and 2.5" ID. The forth is longer about 7" but same OD/ID.
As this machine is used ALL THE TIME, we waited until the time was right. Well yesterday was the day. In the afternoon I tore it down and today the drivers were setup in the lathe to remove about .030" of junk surface and minimize the time on the universal grinder. While that was happening I pressed out the old bearings and installed the new bearings after the grease holes and channels were cut in. By 3 pm today the rolling mill was up and running, with new bearings, lube system for the rest of the machine flushed, lube filter changed and the new bearings greased and buttoned up.
The damage was the same for ALL the bearings. I would not expect that all would have gone bad due to poor maintaince and in fact we hit the grease fittings every 2 months, the RPM is only 2 to 5 and grease works well for this application. I believe that in the past prior to our buying the mill that the damage was caused by poor thinking. The machine is old enough that I think someone decided to change from oil lube for the bearings to grease. He removed oil feed tubes and threaded the holes for grease fittings. The chips were not cleared and the pictures show what the result was.
Note that the machine was to have been rebuilt by the vender. This I firmly doubt as so does the owner.
I thought you may like to see what the old bearings looked like. This is 1 of 4 and they all look the same. I added a picture of a small rolling mill and the arrow is pointing to where the drivers live.
