Excavator bucket tooth structure and improvement method

Excavator bucket tooth is an important part of excavator that is in direct contact with excavation medium. There are two common structures of excavator bucket teeth: straight and horizontal. Direct installation means the pin and bucket teeth are installed vertically; horizontal installation means the pin and bucket teeth are installed in parallel.

1. The direct mounting structure is more convenient to disassemble and install, and it is suitable for the case of short bucket tooth spacing and long pins. Because if installed horizontally, the pins will interfere with adjacent bucket teeth when removing individual bucket teeth. When digging, the direct load pin will be squeezed by the digging material. If the digging force is high, the direct-load bucket tooth structure cannot meet the requirements, and the pin will easily fall off. Therefore, although this structure is easy to disassemble, it cannot be used for excavators with high digging force and high tonnage.

2. Cross-mounted structure, inconvenient to disassemble. Due to the long pins, when dismantling individual bucket teeth, special long rod tools should be used for disassembly and installation to avoid interference between the pins and bucket teeth. During excavation, the cross mounting pin will not be extruded by the excavation material and can withstand greater excavation force. However, the snap spring is prone to wear out when subjected to reciprocating lateral force during use, resulting in the pin falling off.

For both of the above bucket tooth structures, wear will occur in the course of use. Discussing and analyzing only from the structural aspect of the time line, the bucket tooth structure needs to be improved as follows.

1. Impact effect. In most cases, the spring between the tooth seat and the gear sleeve (i.e., between the tooth tips) is connected by a pin. This connection requires a certain clearance between the tooth seat and the gear sleeve to ensure that the mating hole has an alignment margin. If there is no clearance, assembly will be very difficult, processing and manufacturing to achieve a certain level of accuracy, which is not feasible. Under the action of impact force (frequent impact force when digging hard material), strong impact and friction between tooth seat and gear sleeve, resulting in temperature rise, reducing the hardness and impact toughness of material, leading to rapid wear of tooth tip and impact fracture of tooth seat. In addition, high local pressure of hydraulic oil in the hydraulic system (which may lead to chattering) due to repeated shocks can lead to aging failure of sensitive hydraulic and electrical components, and direct and long-term effects may also lead to arm and bucket rod fracture. Moreover, the high frequency of pulse transmission, combined with the sharp noise generated by the pulse, can make the operator uncomfortable. The high local pressure of the hydraulic fluid in the hydraulic system (which can lead to chattering) can lead to aging failure of sensitive hydraulic and electrical components, and the direct and long-term effects can also lead to arm and bucket rod fractures. Moreover, the high frequency of pulse transmission, coupled with the sharp noise generated by the pulse, can make the operator feel uncomfortable.

2. The impact of digging force and digging speed. Without affecting the impact force, high digging force and speed can also cause hard friction between the sleeve and the valve seat, which leads to local temperature increase. In the excavation process, water and air in the gap between the seat and sleeve are heated rapidly due to the harsh working conditions, causing rust in the part of bucket teeth with low surface roughness, accelerating adhesion oxidation and hardening and damaging the bucket body. Under the action of larger digging force, the tooth surface layer and metallurgical organization, so that the bucket teeth can not meet the requirements of use, reducing the efficiency of excavation.