Case Study: Oil Analysis Finds Imminent Bearing Failure

In early December 2013, Bodine performed an oil analysis and vibration analysis on a gear reducer for a 2,150 HP motor at a power plant. The vibration analysis indicated that the input bearing on the reducer was failing, but sufficient vibration history was not available to trend the progression. Because of the critical nature of the reducer, an oil analysis was recommended.

That analysis showed suspected bearing particles were present in the sample, and Bodine recommended the reducer be removed from service and reconditioned.

Bodine later received a call from the customer on Christmas Day to schedule service on the reducer. Additional analysis showed the vibration had progressively worsened.

With the importance of returning the reducer to working order, Bodine performed the work on site, completing around-the-clock repairs for four days.

Further analysis of the input bearing showed severe, advanced spalling on both of its raceways and rolling elements. It was clear the reducer was removed from service shortly before imminent bearing failure. Keeping the reducer operational was critical to the power plant’s normal operations, and thus the customer had been unable to change the oil at the frequency recommended by the manufacturer. Bodine recommended switching from a mineral base oil to a synthetic to extend time between oil changes.