Tooth is an important part of the excavator, similar to our human teeth, and is also a vulnerable part. It is a combination of tooth holders and tooth tips, which are connected by pins. Since the tooth wear failure portion is mostly the tooth tip, the dead tooth can be replaced only by the tip.
Excavators equipped with tooth teeth are mostly very harsh due to their working environment and conditions. Therefore, the performance of the tooth failure is generally abrading, and a few will break, so it is a part that is easy to wear and consume. The excavator tooth is a cantilever beam structure. During construction, the tip of the tooth is inserted into the material pile. When the material is loaded into the bucket during rotation, the tooth has a certain impact when it is just in contact with the material. To withstand bending moments, wear out for a long time throughout the use and thus fail.
The tooth working face is in contact with the excavated object, and the force is different in different working stages in a complete excavation process. When the tip of the tooth first contacts the surface of the material, the tip of the tip is subjected to a strong impact due to the faster speed. If the yield strength of the teeth is low, plastic deformation will occur at the tip. As the depth of the excavation increases, the force on the teeth will change. When the tooth cuts the material, the tooth moves relative to the material, and a large positive pressing force is generated on the surface, thereby generating a large friction between the tooth working surface and the material. If the material is hard rock, concrete, etc., the friction will be very large. The result of repeated action of this process produces varying degrees of surface wear on the tooth working face, which in turn produces a furrow with a greater depth. The positive pressure of the front working face is obviously larger than that of the rear working face. The front working face is seriously worn. It can be judged that the positive pressure and friction force are the main external mechanical factors of the tooth tooth failure, and play a major role in the process of failure.
At the same time, the excavator driver should pay attention to the angle operation during excavation. When mastering the excavation as much as possible, the bucket teeth should be perpendicular to the working surface when digging, or the camber angle should be no more than 120 degrees to avoid breaking the teeth due to excessive inclination. Also be careful not to swing the excavating arm to the left or right with a large resistance. This will cause the tooth and the tooth to be broken due to excessive force on the left and right. Because the mechanical design principle of most types of teeth does not consider the left and right forces. design.
The above content about the failure analysis of the ESCO bucket teeth is explained by Nix, technical engineer of the after-sales service department of A&S Bucket Teeth Co., Ltd.