Theoretical Analysis of the Effects of Instantaneous Charge Leakage on Roller Tracks of Roller Bearings Lubricated With High Resistivity Lubricants Under the Influence of Electric Current

Abstract

An analysis is presented for determining the effects of instantaneous charge leakage on the rise of contact temperature between rollers and roller track of races of roller bearings lubricated with high resistivity lubricant. Analysis is also given for the contact stresses on the races which lead to initiation of craters by the arcing effect on the roller tracks and subsequent damage to the roller bearing. Estimates of the leakage of charge between roller tracks and rollers during momentary asperity contacts along with an expression for the instantaneous contact resistance between roller and race was used to establish heat generated and instantaneous temperature rise in the contact zone on the roller tracks in each shaft revolution. Using this temperature rise, the contact stresses were determined and the minimum number of cycles was calculated before craters are initiated on the roller track of the races. The number of cycles thus determined corresponds, within the reasonable limits, to the appearance of the craters on the roller track of the inner race of a roller bearing, operated under the influence of electric current. Subsequently, the ratio of reduction in bearing life with that of the bearing operated under rolling friction without the influence of electric current is established. This paper gives general guidance for determination of instantaneous temperature rise due to charge leakage in the contact zone and makes it possible to predict the life of a roller bearing lubricated with high resistivity lubricant under the influence of electric current before the craters appear on the roller tracks.