Excavator bucket teeth are an important part of the excavator in direct contact with the excavation medium. The common structures of excavator bucket teeth are straight and horizontal. Direct installation means that the pin and bucket teeth are installed vertically; horizontal installation means that the pin shaft and bucket teeth are installed in parallel.
1. Direct mounting structure, more convenient disassembly and assembly, suitable for occasions with short tooth pitch and long pins. Because if it is installed horizontally, when a single bucket tooth is removed, the pin will interfere with the adjacent bucket teeth. When digging, the direct load pin will be squeezed by the excavated material. If the digging force is large, the straight-load bucket tooth structure cannot meet the requirements, and the pins are easy to fall off. Therefore, although this structure is easy to disassemble, it cannot be used for excavators with large digging force and large tonnage.
2. Cross installation structure, inconvenient to disassemble. Due to the long pins, when disassembling individual bucket teeth, special long rod tools should be used for disassembly and assembly to avoid interference between pins and bucket teeth. The cross mounting pin will not be squeezed by the excavation material during excavation, and can withstand greater excavation force. However, the jumper is easily worn when subjected to reciprocating lateral force during use, causing the pin to fall off.
The above two bucket tooth structures will wear out during use. Only discussing and analyzing from the structure of the timeline, the tooth structure needs to be improved as follows.
1. Shock effect. In most cases, the springs between the adapter and the gear housing (ie between the tooth tips) are pinned. This connection requires a certain clearance between the tooth seat and the gear sleeve to ensure that the matching holes have an alignment margin. Without clearance, assembly would be difficult, and manufacturing would require a level of precision that would not be feasible. Under the action of impact force (often impact force when excavating hard materials), strong impact and friction will occur between the tooth seat and the tooth sleeve, resulting in an increase in temperature, reducing the hardness and impact toughness of the material, resulting in rapid wear and impact of the tooth tip Teeth fractured. In addition, the local pressure of the hydraulic oil in the hydraulic system is too high (which may cause chattering), and the sensitive hydraulic and electrical components will age and fail due to repeated shocks. The immediate and long-term effects may also cause the stick and the stick to break. In addition, the high frequency of pulse transmission, combined with the high-pitched noise generated by the pulses, can be uncomfortable for the operator. Excessive local pressure of the hydraulic oil in the hydraulic system (causing chatter) can lead to aging failure of sensitive hydraulic and electrical components, and the immediate and long-term effects can cause sticks and sticks to break. Also, the high frequency of pulse transmission, combined with the high-pitched noise generated by the pulses, can be uncomfortable for the operator.
2. The influence of digging force and digging speed. Without affecting the impact force, the large digging force and speed will also cause hard friction between the sleeve and the valve seat, resulting in local temperature rise. During the excavation process, due to the harsh working conditions, the water and air in the gap between the valve seat and the sleeve are heated rapidly, resulting in rusty parts of the bucket teeth with low surface roughness, accelerated adhesion, oxidation hardening, and damage to the bucket body. Under the action of a large digging force, the tooth surface layer and metallurgical structure make the bucket teeth unable to meet the use requirements and reduce the digging efficiency.