Estimation of Rolling Bearing Life under the Environmentof Electrical Erosion using Accelerated Life Test

Abstract

This study experimentally investigates the life of rolling bearings in electric vehicles under electrical erosion. The design and preparation of an electrical erosion simulation test rig, setting of accelerated life test conditions and test methods, and results of life analysis under electrical erosion are described. We selected a constant current as the acceleration factor for life under electrical erosion, and an electrical erosion life test was conducted using three current values. The bearing was determined to have failed when the root mean square value of the acceleration data from the bearing was 4 g or higher. Based on the test data, a formula to predict life under electrical erosion was developed and used to estimate life under electrical erosion when the bearing was exposed to a random current value. The Weibull distribution was used to estimate the life of the bearing under electrical erosion based on the results of the statistical analysis that used the accelerated life test data. The estimated values were presented considering the shape parameter, acceleration index for a constant current, and the uncertainty of the estimated life value. The acceleration indices for the shape parameter of the electrical erosion life data distribution and constant current were 3.391 and 0.776, respectively. The B10 life values were 51.7, 14.8, and 8.7 h when the supplied currents were 0.1, 0.5, and 1, respectively. This study provides empirical guidelines for predicting the life of ball bearings under electrical erosion.