Friday, August 3, 2012

(9) Bearings Used on Old Mining Artifacts

Bearings Used on Old Mining Artifacts. Today we see steel ball bearings, roller bearings, and bronze sleeve bearings used in our rotating mining equipment. Back in the 1890’s rotating equipment used bearings constructed of cast iron pillow block bodies with babbitt packed into the housing which encapsulated a rotating shaft. During these early days mining operations used one driver: a steam engine, pelton wheel, or electric motor to supply power through multiple shafts supported with pillow block babbitt bearings. They could drive the stamp mill, crusher, and shaker table with one motor. The bearings used were primarily common pillow block babbitt bearings. The picture below shows typical applications of these pillow block bearings.

 To give the bearings long life either oil or grease would be used to lubricate and transfer heat from the shaft through the bearing housing. The expression "run bearing" also was derived from this style of bearing, since failure of lubrication will lead to heat build up due to friction in the bearing, eventually leading to the bearing metal liquefying and running out of the pillow block.
Babbitt was made typically from alloys of tin, lead, antimony, and copper. The "XXXX Nickel" is a trade name for such an alloy that also contains a small percentage of nickel.
The pictures below are ingots of babbitt weighing 4 to 5 pounds each. Today babbitt is not cheap.  The babbitt in the ingots run about $12 a pound if you can find it. There are not many vendors that still handle babbitt. I purchased this babbitt at a Mining Artifact Show in Grass Valley, California. This a a great palce to find many rare mining artifacts such as babbitt.


There are many Babbitt alloys with some common compositions:
  • 90% tin, 10% copper
  • 89% tin, 7% antimony, 4% copper
  • 80% lead, 15% antimony, 5% tin
  • 76% copper, 24% lead
  • 75% lead, 10% tin
  • 67% copper, 28% tin, 5% lead

1 comment:

  1. Hi Charlie, in your travels restoring stamp mills have you come across any engineering businesses in the US that still manufacture and sell NEW 3,5 & 10 stamp mill batteries? I ask because we still use stamp mills commercially in gold production. For a variety of reasons (an entire discussion in itself)we never changed over to ball mills and more modern ore reduction techniques. So our stamp mills work commercially rather than as historical pieces. Any leads on US stamp mill manufacturers still operating would be most welcome. I enjoy your blog and the work you are doing is very similar to what we do daily to maintain our production circuits, although I do think we change out many more shoes and dyes. Martin Miedler, Harare, Zimbabwe, Africa.

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