According to the bucket, excavators can also be divided into forward shovel excavators, backhoe excavators, dragline excavators, and grab excavators.
Positive excavators are mostly used to excavate materials above the surface, while backhoe excavators are mostly used to excavate materials below the surface. 1. The front shovel excavator is suitable for excavating soil with a water content of less than 27%, rock and frozen soil fragments after blasting, large-scale site leveling earthwork, large pipe trenches and foundation trench cuttings with narrow and deep working faces, independent foundation pits, and slope excavation. The excavation characteristic of a front shovel excavator is "forward and upward, forced cutting of soil". The characteristic of the shovel action form of the front shovel excavator is "forward upward, forced cutting of soil". The front shovel has a large excavation force and can excavate the soil above the parking surface. It is suitable for excavating dry foundation pits with a height of more than 2m, but it is necessary to set up an up and down ramp. The bucket of a front shovel is larger than that of a backhoe with the same equivalent. It can excavate Class I to Class III soil with a water content of no more than 27%, and cooperate with a dump truck to complete the entire excavation and transportation operation. It can also excavate large dry foundation pits and mounds. The excavation method of a front shovel excavator depends on the relative position of the excavation route and the transportation vehicle. There are two methods for excavation and unloading: forward excavation, lateral unloading, forward excavation, and reverse unloading. 2. Backhoe excavator Backhoe type is the most common type we have seen, which is backward downward and forced to cut soil. It can be used for excavation below the shutdown working surface. The basic operation methods include: trench end excavation, trench side excavation, straight line excavation, curve excavation, maintaining a certain angle of excavation, ultra deep trench excavation, and trench slope excavation. Backhoe excavators are suitable for excavating sandy soil or clay with high water content, and are mainly used for excavation of foundation pits (trenches) or pipe trenches, independent foundation pits, and slopes with a small depth below the parking surface. Backhoe excavators are characterized by "backward downward, forced soil cutting.". 3. Grab excavator Grab excavator is also called grab excavator. The characteristics of soil excavation are: "straight up and straight down, cutting soil by self weight". It is suitable for excavation of Class I and II soil below the parking surface, and is commonly used for excavation of foundation pits, open caissons, etc. in soft soil areas. It is particularly suitable for digging deep and narrow foundation pits, dredging old channels, digging mud in water, etc., or for loading loose materials such as gravel and slag. The excavation methods include trench side excavation and positioning excavation. If the grab bucket is made into a grid bar shape, it can also be used for loading ore blocks, wood chips, wood, etc. in a wood storage yard. 4. Dragline excavator Dragline excavator is also called cable shovel excavator. The characteristics of soil excavation are: "backward downward, cutting soil by self weight". It is suitable for excavation of Class I and II soil below the parking surface. When working, use inertial force to swing the bucket out, digging farther, with a larger excavation radius and depth, but not as flexible and accurate as a backhoe. Especially suitable for excavating large and deep foundation pits or underwater excavation.