A petrochemical refinery was experiencing increased failures on centrifugal pump bearings. NSK was consulted and performed a bearing failure investigation which showed roller skidding due to insufficient radial load. It was also revealed that the customer had recently changed the motor drive from belt to direct drive. This resulted in removal of the belt load and a consequential reduction of radial loading. Taking this into consideration NSK engineers proposed an alternative Deep Groove Ball Bearing set-up. A trial was investigated, which demonstrated that the bearing life was extended to over 3 times that of before. In fact, there were no breakdowns in a 1 year period with pump remaining running. This resulted in a significant reduction in maintenance costs and productivity improvements.
|Before||Cost p.a.||NSK Solution||Cost p.a.|
|Old Bearings Costs||$161||Replacement Bearing Costs||$27|
|3 Breakdowns / 6 hour change over for 2 people / Labor cost $21 / hour||$772||No Breakdowns||$0|
|3 breakdowns / 6 hours / Loss production cost $1,607/hour||$28,926||No Breakdowns||$0|