Effect of WC/C coated rolling element to improve bearing life

Abstract

The research is aimed to understand the effect of WC/C coating on the bearing rolling elements to improve fatigue life in surface distress conditions. The 1-1.5 microns optimized coating thickness was deposited on the steel substrate using the PVD process. The coating's physical and chemical properties were analysed by X-ray diffraction, scanning electron microscope, contact profilometer, nanoindentation hardness, and micro scratch indenter. The wear properties were compared on a ball-on-disc tribometer with and without a coated specimen. The bearing tests were performed in contaminated and clean lubrication conditions to prove the coating's effect on bearing life in surface distress conditions. Results show that coated roller bearings perform at least two times that of the standard bearing. The overall benefit of less friction and wear resistance was due to the polishing action and coating transfer mechanism of multi-layer coating which increases oil film thickness between contacts and hence improve bearing life.

Failure Mechanism of Bearings under Extremely Cryogenic Conditions

“…At this stage, for cryogenic rotating equipment, the running status of its key components bearing directly affects the performance and safety of the entire equipment. Therefore, developed countries such as the United States and Japan will improve bearing performance and improve bearing life as a research focus [10][11][12][13]. However, the key factors causing bearing failure and failure mechanism are still unclear.…”