Theoretical Analysis of Capacitive Effect of Roller Bearings on Repeated Starts and Stops of a Machine Operating Under the Influence of Shaft Voltages

Abstract

A theoretical analysis has been carried out to study the capacitive effects of roller bearings on repeated starts and stops of a machine operating under the influence of shaft voltages. The analysis gives the time required for the charge accumulation and increase of charge with time on the bearing surfaces based on bearing capacitance, resistance of film thickness and the shaft voltage. Also, it investigates the effect of gradual leakage of the accumulated charges with time as the shaft voltage falls as soon as the power supply to the machine is switched off. This paper gives an approach to determine ratio of the number of shaft revolutions required for charge accumulation and gradual discharge of the accumulated charges on the bearing surfaces depending on bearing to shaft voltage. Also, number of repeated starts and stops before initiation of craters on roller track of races are established to restrict the deterioration and damage of bearings.