Ineffective Rock Breaking and its Impacts on Pick Failures

Picks are critical components in excavation machines used in civil and mining industries. Any failures of picks in an excavator directly affect the reliability and productivity of the machine. Pick tip wear, pick tip crack, pick body wear and pick body bending are common failure modes of picks in production. Among various failure causes, ineffective rock breaking during a cutting process is a major cause which can result in most of these failure modes. In this paper, the mechanism of ineffective rock breaking is investigated and the influences of ineffective rock breaking on pick failures are studied. It shows that apart from pick tip geometry, pick installation angles on a drum and rock properties, pick lacing space is a major factor that affects the effectiveness of rock breaking. More importantly, it is a more controllable parameter in the drum design stage. The results of this research can be used to reduce pick failure probability, and automate optimal drum design.