Experimental Study on Reducing the Adherence Phenomenon between Idle Gear and Housing for Low-Pressure Fuel Pump of Excavator Engine

sThis paper describes the adherence phenomenon, including the tribological characteristics, of a low- pressure fuel pump in a diesel engine for an excavator. Most fuel pumps of a diesel-engine excavator are of the fixed-quantity-gear type and have low pressure. However, the developed pumps develop problems in the pump- ing system owing to performance instability. Cavitation, which is the main obstacle to stable driving in the pump, occurs between an idle gear and the housing to produce a serious adherence problem. The present study not only examined how to suppress cavitation in a pump but also developed a simple method to improve pump per- formance through the early creation of a lubrication film with a phosphoric acid coating on the surface of the idle gear. The results showed that the coating successfully prevents breakage of the idle gear due to adherence. Keywordsexcavator(굴삭기), fuel pump(연료펌프), gear(기어), adherence(응착), coating(코팅), housing (하우징)