Estimating the Fatigue Life of Bearings
Introduction
The fatigue life of bearings is an important issue for many industries and applications. The primary aim of this paper is to present an overview of the current understanding of the fatigue life of bearings, as well as a review of the most commonly used methodologies for estimating the likelihood of bearing failure due to fatigue.
Background
The fatigue of bearings is a process that can be caused by a multitude of factors, including unsuitable design, poor lubrication, extreme operating conditions and improper mounting. The fatigue process is the progressive deterioration of a component or material due to the repetitive nature of stress. For bearings, fatigue phenomenon is caused by the rolling motion, which creates high-cycle vibration, stress concentrations, and contact loading.
The fatigue life of a bearing is determined by many factors, such as alloy composition, material properties, physical size, surface finish, load distribution, operating temperature, corrosion, and lubrication. For these rules, life extension is achieved by optimizing the operating load, operating frequency and lubrication requirements.
Analysis of fatigue life
Modern fatigue analysis involves the application of probabilistic methods that combine experimental data with theoretical principles to determine bearing life estimation. These approaches allow engineers to evaluate the performance of a bearing design through life-damage relationships.
The most common models used to predict the life of bearing under fatigue loading are the Ball-bearing Designdamage curve model and the Multcrown Life-load curve model. The former is based on Larson-Miller parameter, allowing prediction of the fatigue life of a single bearing or an assembly of multiple bearings. The latter, meanwhile, determines the dynamic load of a bearing and its influencing factors, as well as its dynamic fatigue, and enables the life of the bearing to be predicted.
Conclusion
In conclusion, fatigue life estimation of bearings is an important consideration in any design process. Current methods of estimating the likelihood of bearing failure due to fatigue are based on a combination of data and theoretical principles. By optimizing design parameters such as alloy composition, material properties, physical size, and surface finish, engineers can extend the fatigue life of a bearing.
The ball bearing design-damage curve and the Multcrown life-load curve are two of the most commonly used models for predicting bearing life under fatigue loading. Through these models, engineers can develop more reliable life estimates and thereby improve product performance.
