Classification of excavators

Excavators can usually be classified in the following ways:

• Crawler excavators: This is one of the most common types. It is characterized by walking on crawlers, which gives it good stability and off-road performance. It can travel on various complex terrains, such as muddy areas and rugged mountain roads. The crawlers have a large contact area with the ground, resulting in low pressure on the ground, and it is not easy to sink into soft ground, making it suitable for working in harsh working conditions.
• Wheeled excavators: They move on tires, with relatively fast driving speeds, which makes it convenient to transfer between construction sites. They can drive quickly on highways, saving transportation costs. They have good mobility and can flexibly shuttle through urban roads, small construction sites and other places. However, the stability of wheeled excavators is relatively poorer than that of crawler excavators. When working on soft or uneven ground, the tires are likely to sink or the excavator may tip over.
• Walking excavators: This kind of excavator moves through a special walking mechanism. It can move the body forward step by step, just like a person walking. The advantage of walking excavators is that they can work in some special sites, such as narrow spaces and areas with obstacles, and they have strong flexibility and adaptability. However, their walking speed is slow, and the work efficiency is relatively low.

• Front shovel excavators: The working device of a front shovel excavator digs forward and upward, and the tip of the bucket tooth moves from bottom to top. It has a large digging force and can excavate the soil above the parking surface. It is suitable for earthwork projects with a large digging height and hard soil, such as open-pit mine mining and the excavation of large foundations.
• Backhoe excavators: The backhoe excavator is the most commonly used form of working device. Its bucket digs backward and downward, and the tip of the bucket tooth moves from top to bottom. It is mainly used for excavating the soil below the parking surface and is suitable for projects such as excavating foundation pits, trenches and rivers. It has the characteristics of large digging depth and flexible operation.
• Dragline excavators: The bucket of a dragline excavator is suspended on the boom by a steel cable. During operation, the bucket is first placed on the ground, and then the bucket is dragged on the ground by pulling the steel cable to load the soil into the bucket. Then the bucket is lifted and rotated to the unloading position for unloading. It has a large digging radius, but the digging depth is relatively shallow. It is often used for projects such as excavating large foundation pits, river dredging and soil borrowing sites.
• Clamshell excavators: The working device of a clamshell excavator is a clamshell, which is composed of two or more jaws and is opened and closed by a steel cable or hydraulic drive. Clamshell excavators are mainly used for grabbing loose materials, such as coal, ore, garbage, etc. They can also be used for grabbing underwater objects, such as salvaging sunken ships and clearing debris in rivers.

• Diesel engine-driven excavators: Using a diesel engine as the power source, they have the advantages of high power, large torque and stable power output, which can meet the operating requirements of excavators in various complex working conditions. Diesel engine-driven excavators have a wide range of applications and can be used in various environments such as the wild, mines and construction sites. However, they need to be refueled regularly, and the exhaust gas emitted by the engine may cause certain pollution to the environment.
• Electric motor-driven excavators: Using an electric motor as the power source, they have the advantages of low noise, no pollution and low operating costs. They are suitable for use in urban environments, indoor operations or places with high environmental protection requirements, such as urban subway construction and the demolition and renovation of buildings. However, electric motor-driven excavators require a stable power supply, and the operating range is limited by the power lines.
• Hybrid-driven excavators: Combining the advantages of diesel engines and electric motors, by equipping the excavator with a hybrid system, the power source can be automatically switched under different working conditions to achieve the goal of energy conservation and emission reduction. For example, a diesel engine is used to provide strong power during the digging operation, while an electric motor is switched to drive during walking or standby, reducing fuel consumption and exhaust emissions.

• Small excavators: Generally, they refer to excavators with a total machine mass of less than 6 tons. They have the characteristics of being compact, flexible, easy to operate and having a low investment cost. They are suitable for small earthwork projects, municipal construction, farmland water conservancy construction, garden cultivation and other fields.
• Medium-sized excavators: The total machine mass is usually between 13 and 30 tons. Medium-sized excavators have moderate power and digging ability, and can adapt to most conventional earthwork projects and construction tasks, such as the excavation of the foundations of general buildings, road construction, and the excavation of large foundation pits.
• Large excavators: The total machine mass is more than 30 tons. Large excavators have a powerful digging force and loading capacity, and can play an important role in large-scale mine mining, large-scale water conservancy projects, large-scale infrastructure construction and other projects, and can achieve efficient earthwork excavation and transportation operations.