TBM single disc cutters

الوصف

Single disc cutters are mainly applied to bore in hard rock or mixed ground. Single disc cutters break rock into chips, rather than crushing it into fines or ripping it from the face. The rotating disc cutters create “crush zones” through which fractures propagate. Chips are then broken away from the face. This action makes single disc cutters excellent in solid rock. Ground conditions determine cutters selection and characters, such as ring material, ring hardness, hub hardness, ring profile and width, cutters starting torque, seal and so on. To improve ring wear resistance and toughness, ring is made from alloy tool steel and specially heat-treated to reach proper balance of hardness (HRC****9) and toughness. Tungsten carbide tips will be inserted in ring if cutters are applied in very abrasive ground. To improve boring efficiency, ring is made into different profiles and width for different ground conditions. To improve hub wear resistance in abrasive ground, hub is heat-treated up to HRC*0, or coated wear resistance material in exposed section. According to working conditions, cutters starting torque is adjusted to proper level (*****) by preloading in order to rotate freely and prevent them becoming blocked.