The bucket teeth of an excavator are the main vulnerable parts of the excavator, similar to human teeth. They are composed of a combination of a tooth seat and a tooth tip, which are connected by a pin shaft. Due to the wear and failure of the bucket teeth, the tooth tip is the only part that needs to be replaced.
1、 Structure and function of bucket teeth
According to the bucket tooth seat. The bucket teeth of excavators generally have two structural forms, namely, the direct mounted type and the horizontal mounted type. The direct installation type refers to the vertical installation of the pin shaft and the front face of the excavation bucket tooth; Horizontal installation refers to the installation of the pin shaft parallel to the front face of the digging bucket teeth.
(Direct Mount/Horizontal Mount)
Direct mounting type: It is convenient to disassemble, directly smashing from above, and has a large operating space. During excavation, the directly installed tooth pin will face the squeezing force of the excavated material. If the excavation force is large, the clamping force of the expansion spring cannot meet the requirements, which can easily lead to the tooth pin falling off.
Therefore, the direct loading type is generally used on excavators with smaller excavators and lower tonnage.
Horizontal installation: it is not convenient to disassemble, the side operation space is small, and awesome is difficult. When disassembling a single bucket tooth, special long rod tools must be used in sequence. During excavation, the front face of the laterally mounted tooth pin will not be subjected to the squeezing force of the excavated material and can withstand a large excavation force. However, when the expansion spring is subjected to reciprocating lateral forces during use, it is prone to wear and failure, resulting in the tooth pin falling off.
Therefore, the horizontal type is generally used on excavators with a digging force of more than 20 tons.
Classification based on the environment in which excavator bucket teeth are used. Excavator bucket teeth can be divided into rock teeth (for iron ore, stone ore, etc.), earthwork teeth (for digging soil, sand, etc.), and tapered teeth (for coal mining). However, the bucket tooth shapes of different brands of excavators also have their own characteristics.
(Rock tooth/Earth tooth/Cone tooth)
Why do excavators need bucket teeth? With so many bucket teeth, we can also see that:
1. Protect the entire bucket. Bucket teeth are wear and tear parts. Due to the large wear and tear of the bucket during operation, combined with bucket teeth, the bucket is protected to a certain extent.
2. Make the operation more precise. For operations that require fine operation, it is impossible to achieve without bucket teeth.
3. Easy to dig and shovel. The bucket teeth are tapered, and there is a gap between the bucket teeth. This way, the force acting on the entire bucket becomes smaller, the pressure increases, and the operation becomes smoother.
4. After digging hard things, it can play a buffer role for the entire machine.
2、 Selection and purchase of bucket teeth
Bucket teeth generally have the difference between cast bucket teeth and forged bucket teeth. Generally, forged bucket teeth are more wear-resistant, have greater hardness, and have a service life of about twice that of cast bucket teeth, while the price is about 1.5 times that of cast bucket teeth.
Casting bucket teeth: The method of casting liquid metal into a casting cavity suitable for the shape of the part, and then cooling and solidification to obtain the part or blank is called casting. Castings are prone to air holes and formation of sand holes, and their mechanical properties, wear resistance, and service life are lower than those of forgings.
Forging bucket teeth: Using a forging machine to apply pressure to a special metal blank, it is extruded under high temperature to refine the crystalline material in the forging, causing it to undergo plastic deformation to obtain certain mechanical properties. After forging, the metal can improve its organizational structure, which can ensure that the forged bucket teeth have good mechanical properties, more wear resistance, and longer service life.
Of course, when purchasing bucket teeth, we also need to determine the type of bucket tooth based on the working environment in which the excavator is used.
Generally, flat mouth bucket teeth are used for soil excavation and sand dispersion. Secondly, RC type bucket teeth are used for excavating massive hard rock, and TL type bucket teeth are generally used for excavating massive coal seams.
In addition, in the actual operation process, most people like the common RC bucket teeth. The editor recommends not to use the RC bucket teeth in general, and it is best to use the flat bucket teeth. Because the front wear of the RC bucket teeth after a period of time increases the digging resistance and wastes power, while the flat bucket teeth always maintain a sharp surface during the wear process, reducing the digging resistance and saving fuel.
3、 Recommendations for maintenance and extended service life of bucket teeth
During the use of the bucket teeth of the excavator, the outermost bucket teeth of the excavator are 30% faster than the innermost wear parts. After a period of time, the bucket teeth can be shifted from inside to outside.
When operating, the excavator driver should try to dig under the bucket teeth perpendicular to the working surface, to avoid breaking the bucket teeth due to excessive inclination.
3. Do not swing the excavation arm left and right with great resistance, as this can easily cause the bucket teeth and tooth seats to break due to excessive left and right forces, and the design of left and right forces is not considered.
4. It is recommended to replace the gear seat when it is worn by 10%. There is a large gap between the excessively worn gear seat and the bucket tooth, which changes the fit and force point of the bucket tooth and the gear seat, and the bucket tooth breaks due to the change in force point.