Tribological wear of diesel engine atomisers

The authors indicate design changes in injection systems that result in increased tribological loads of atomizers. It is observed that mechanisms of tribological wear of atomizers should be examined in detail. The following four tribological nodes were identified in an atomizer: guide-cylindrical part of the needle, atomizer seat-closing cone of the needle, needle front surface-front surface of injector spring, atomizer front surface-body front surface. A limited set of one type of atomizers was visually examined. Typical images of damage for each node are presented and wear mechanisms are described as well as the feedback between the technical conditions of atomizer tribological nodes and the node load. The authors indicate that: the technical condition of the needle-guide node affects the force imposing a load on the other nodes; the wear of needle front surface-spring node and the seat-needle cone node results in an increased travel of the needle; the time to failure should be considered as the time to the loss of tightness and depends on the distribution of wear on the ring circumference of the conical seat-needle contact.