Residual life prediction of large-size slewing bearings based on small-sample test

A residual life prediction approach for slewing bearings was proposed based on a small-sample test. Firstly, a residual life prediction model for slewing bearings was established based on modified Weibull distribution. Then, the load distribution over the slewing bearing raceway was analyzed on the basis of Hertz's theory. Afterwards, a new method for Weibull parameters estimation was proposed based on a small-sample test, which utilized the Archard theory and the Anti-power acceleration life model. Finally, an experiment was conducted on an inner-geared slewing bearing (QNA-730-22) to verify the proposed approach. The results show that the fatigue life distributions of multiple samples in multiple load cases can be determined through one life-cycle experiment, and that the proposed approach is closer to engineering practice compared with the NREL design guide and the ISO 281. Besides, the modeling procedure of the proposed method is efficient and time-saving, and all the merits of the method provide a potential for enterprises in making timely proactive maintenance schedules.