A Study on Wear of Carbon Flat Commutator and Brush of DC Motor for Automotive Fuel Pump

摘要

In an automotive fuel pump system, a small DC motor is widely used to drive the pump. The authors have been reporting the wear of brush and carbon flat commutator in gasoline and ethanol so far. In this paper commutation period, arc duration, brush and other characteristics are examined in ethanol 50-gasoline 50%. Brush wears are very small compared with the previous results. Namely mechanical sliding wear is predominant rather than erosion by arc due to short arc duration. Further, an area eroded by arc is observed to come back to a sliding surface. From these results a wear model is proposed to explain this phenomenon.