Relationship Between Vibration Energy and Wear Condition of Ball Bearings Based on Reye’s Hypothesis

This paper deals with the study of the correlation between the dynamic behavior of a failed ball bearing and wear defect development. Ball bearings are intensively used in industrial applications as supports for rotating machines, so a failure of those components produces unexpected downtime of the line-production. Most of the literature techniques focus on the early detection of localized faults on bearings (e.g. on the outer ring), but more recently some authors have also worked on distributed faults (e.g. generalized roughness).This paper focuses on distributed faults, in particular on the consequences of a lack of grease in ball bearings. This condition happens when the bearing is not maintained correctly or when it works in hostile conditions (e.g. chemical attack). In such cases there is not a pure rotation of the bearing spheres but friction between races and spheres. As a consequence, the presence of an external load generates friction forces which damage the bearing surfaces and increase the bearing vibration. This paper propose a new approach based on Reye’s hypothesis to assess the wear of the bearing surfaces. According to Reye’s hypothesis the mechanical work of the friction force is proportional to the material volume removed by reason of wear. By means of experimental tests it is possible to evaluate the proportional coefficient and to determine the relationship between the typology and intensity of the vibrations and the failure evolution. The aim of this work is to provide a monitoring methodology able to predict the residual life of the support