Prevention of Smearing Damage in Cylindrical Roller Bearings

Abstract

Smearing damage was created on cylindrical roller bearings (CRBs) using a laboratory test protocol that required alternating the load zone direction according to a square wave function. The experimental goal was to compare the wear protection afforded by various surface treatments, including vibratory superfinishing (ES20), black oxide treatment, and special tungsten carbide–reinforced amorphous hydrocarbon roller body coatings (WC/a-C:H). The only bearing treatments that did not smear in these severe tests were the WC/a-C:H bearings. Black oxide and ES20 bearings experienced smearing with the same frequency as untreated bearings, albeit to different degrees of microscopic damage. The test rig was instrumented to measure cage slip, which provided insight about the roller–raceway slip dynamics during the tests via kinematic calculations. The CAGEDYN bearing dynamics model was used to simulate the experimental smearing test conditions, and it provided encouragement that accurate prediction of smearing risk may be possible in the future with further development.