Excavator Boom Function and Involved Machining Processes

The excavator boom is the core component connecting the excavator body and the working device (such as the stick and bucket). Its core function is to bear and transmit the huge digging force and realize the large-amplitude variable amplitude movement required for digging operations. During operation, the root of the boom needs to withstand the huge thrust from the lifting cylinder and the huge digging reaction force transmitted back from the bucket, which requires it to have extremely high bending and torsional strength. At the same time, the pin holes at its front end, as the hub connecting to the stick, must ensure extremely high position and dimensional accuracy to ensure the coordination and smooth movement of the entire working device.

To achieve these demanding functional requirements, the manufacture of the boom involves a series of key machining processes. First, its box-shaped structure is usually cut and welded from high-strength steel plates. A high standard of welding process is the lifeline to ensure structural integrity, ensuring that the strength of each component connection matches the base material. After welding, the overall structure must undergo stress relief annealing to eliminate internal accumulated welding stress, preventing deformation or cracking due to stress release during subsequent use, thereby greatly improving the dimensional stability and service life of the product. Finally, precision boring of the various pin holes connecting the stick and cylinder is a crucial step. This process directly determines the coaxiality and fit clearance of each moving component. Only through high-precision boring can the boom and the entire working device operate flexibly and accurately under long-term heavy-load and impact conditions, and effectively extend the service life of bearings and pins.