Case study from the Cement industry – Finish Mill Separator

Machine: Finishing mill in a cement plant

Problem description

  • Bearing outer race fatigue
  • Higher than normal vibration

Spectrum indicating fault

  • Test point:  Inboard West Motor Radial
  • Analysis name:   Spectrum 60,000cpm or 1000hz
  • Comment:   Note harmonics of outer race

Spectrum indicating fault

  • Test point:  Inboard West Motor Radial
  • Analysis name:   Spectrum 60,000cpm or 1000hz
  • Comment:   Note harmonics of outer race
  • Trend over 13 months

Spectrum After Repair

  • Test point:  Inboard West Motor Radial
  • Analysis name:   Spectrum 60,000cpm or 1000hz
  • Comment:   No sign of outer race defect

Root cause

  • Defect area in the outer race of the bearing
  • Could have been caused by many factors
    • Lack of lube
    • Dirt, etc.