Beyond the Bearing: Root Cause Analysis of Roksh Separator Recurring Issues

The recurring failure of the middle bearing (SRTB) in Roksh separators at pellet plant. The SRTB, a spherical roller thrust bearing, exhibits frequent failures, with a lifespan significantly shorter than the expected 10 years. Analysis reveals a pattern of severe spalling and wear on rollers and raceways, indicative of inadequate lubrication and high operating temperatures. The investigation highlights insufficient sealing, leading to grease leakage and insufficient lubrication. The use of an unsuitable grease grade (NLGI 1) for the high-axial-load, vertical application exacerbated the problem. Further contributing factors include inadequate assembly practices, resulting in seal damage, and a high material temperature affecting bearing operating temperatures. Comparative analysis with a similar unit reveals significant differences in operating parameters and bearing lifespans. Corrective and preventive recommendations focus on improving seal design, implementing appropriate lubrication practices, refining assembly procedures, and addressing operational parameters. A long-term feasibility study is also recommended to explore design modifications and alternative bearing options to mitigate future failures.