Remanufacturing Process and Improvement in Fatigue Life of Spherical Roller Bearings

Dept. of Mechanical Engineering, Sun Moon University, Asan 336-708, Korea(Received; Setpember 23, 2014 Revised; November 2, 2014; Accepted; November 5, 2014)Abstract − This study proposes a sustainable bearing remanufacturing process using the ultrasonic nanocrystalsurface modification (UNSM) technique. The UNSM technique is a newly developed and sophisticated surfacemodification technique that can increase the mechanical properties and improve the friction and wear per-formance of materials. Taking advantage of the bearing manufacturing process is the most significant way ofoptimizing the life of a bearing. The proper maintenance and usage of repaired bearings can increase their lifeto be equal to or greater than that of new bearings. This paper discusses the restoration of certain mechanicalproperties of worn, damaged, and discarded bearings, and suggests a remanufacturing process for used bearings,which can impart them with a lifespan equivalent to that of new bearings. The most damaged part of the dis-carded bearings is the raceway, which is the site of accumulated fatigue. The existing polishing or barrel finishingprocesses can recover the accumulated fatigue only partially. Rolling contact fatigue tests performed on UNSM-treated new and used specimens polished after 4×10