Field case · Design review
Cement mill counter shaft: three white-metal bearings replaced by two roller bearings, and why the load inputs decide the life
A 2,500 kW mill counter shaft at 124 rpm moves to a located spherical roller bearing and a free CARB bearing. The life figure swings from 13,000 to over 200,000 hours depending on one axial-load input.
What the case covers
- The application
- The proposal
- Why the layout is right
- What the review found
- What the real torque gives
- How the life depends on the axial input
- How to read that table
- Where the axial load should come from
- The free bearing
- Other things to check
- What to do instead
Takeaway. The bearing choice (a located spherical roller bearing and a free toroidal bearing) is sound. The numbers behind it are not yet. Fix the inputs first, because the life depends on them far more than on the bearing.
Read the full case, with the data and the numbers