Bearing Life Equation for Engine Accessory Devices

Abstract

We describe the fatigue phenomena in bearings for automotive alternators. Characterics of this fatigue are as follows. (1) Flakings are concentrated in the outer rings on the pulley side. (2) Flaking occurs faster than the calculated bearing life. In order to analyze and investigate the effect of engine vibration and rigidity of the housing on the bearing life, fatigue tests were carried out using actual engines and alternator simulation test rigs. Eight different test conditions were used to derive the new equation which includes a new load factor. It was suggested that the new equation can be applied to engine accessory bearings.