Importance of Acoustic Emission Method in Evaluation of Durability of Rolling Contact

摘要

Rolling-element bearings are reliable and widely used mechanical components whose life is in the case of correct operating conditions and compliance with the mounting procedures limited only by rolling contact fatigue. In the final stage, the rolling contact fatigue on surface of bearing race resulted in formation of pitting or spalling. This is influenced by many factors: homogeneity and structure of the material, lubricant properties, contact pressure, surface quality, etc. Conducting an endurance test series on full-scale bearings is expensive because numerous test specimens are required to obtain useful experimental life estimation. The flat washer tests allow obtaining in a short time and cheaper the information about durability of material under testing. The life of tested material is commonly determined by vibrodiagnostics. However this method detects only final stage of rolling contact fatigue - pitting and processes during the test are not adequately described. This paper deals with the processes before the onset of the final damage on the surface of the specimen during testing under different conditions (material and lubricant properties) using acoustic emission method. It can be concluded that method of acoustic emission is able to describe changes during rolling contact tests better than vibrodiagnostics and temperature monitoring.