The bulldozer is an engineering vehicle with a large metal bulldozer in front. When in use, put down the bulldozer, cut and push mud, sand and stones forward. The position and angle of the bulldozer can be adjusted. The bulldozer can complete the excavation, transportation and unloading work independently, and has the characteristics of flexible operation, convenient rotation, small working face required, and fast driving speed.

According to engine power, bulldozers can be divided into:
Small bulldozer: power below 37kv;
Medium bulldozer: power: 37-250kw;
Large bulldozer: power above 250kw.
Bulldozing can still be divided into:
Crawler bulldozer: It is a multipurpose machine with large traction, low specific pressure to ground, strong climbing ability and good operation performance.
Tyred bulldozer: It has high driving speed, good mobility, short operation cycle time, convenient and rapid transfer, and does not damage the ground. It is especially suitable for use in urban construction and road maintenance projects. However, the adhesion performance is far less than that of crawler bulldozer, and the scope of use is limited.
Bulldozers can be divided into:
Fixed blade bulldozer: the bulldozer blade is fixed at right angles to the longitudinal axis of the main machine, which is also called shovel bulldozer. Its structure is simple, but it can only push the soil directly in the direction of advance. Its operation flexibility is poor, and it is only used for small and medium-sized bulldozers.
Rotary blade bulldozer: the bulldozer blade can rotate at a certain angle in the horizontal plane, and can be installed at a fixed right angle or a non-right angle with the longitudinal axis of the main machine, also known as angle blade bulldozer. This bulldozer has a wide range of operations, which is convenient for moving soil and excavating side ditches.
Bulldozers can be divided into:
Mechanical transmission bulldozer: the bulldozer with mechanical transmission is reliable in operation, simple in manufacture, high in transmission efficiency and convenient in maintenance. However, it is laborious to operate, and the transmission device has poor adaptability to load, which is easy to cause engine flameout and reduce operation efficiency. It has been less used in large and medium-sized bulldozers.
Hydro-mechanical transmission bulldozer: the combination transmission device of hydraulic torque converter and power shift transmission is adopted, which has the ability of self-driving stepless speed change and torque change, and automatically adapting to external load changes. The engine is not easy to shut down, can shift with load, has less shift times, is easy to operate, and has high working efficiency. It is the transmission form commonly used by modern large and medium-sized bulldozers.
Full-hydraulic transmission bulldozer: driven by hydraulic motor, the driving force is directly transmitted to the traveling mechanism. Because there are no transmission parts such as the main derailment, transmission, drive axle, etc., the structure is compact, the overall arrangement is convenient, the overall weight is light, the operation is simple, and the in-place steering can be achieved. However, the full hydraulic bulldozer has high manufacturing cost, poor durability and reliability, and is only used on the bulldozer with medium power.
Electrically driven bulldozer: converts the mechanical energy output by the diesel engine into electrical energy, drives the motor through the cable, and then drives the walking device and working device. It is compact in structure, convenient in general arrangement, flexible in operation, and can realize stepless speed change and in-place steering of the whole machine. However, due to its high quality and high manufacturing cost, the whole machine is only used on a few high-power wheeled bulldozers.
The bulldozer can be divided into:
Wire rope bulldozer: the lifting and lowering of the blade is controlled by the wire rope. The blade enters the soil by its own weight and cannot be forced to cut the soil. There are many friction parts of the mechanism (such as pulleys and power hinges), which are easy to wear. The operating mechanism needs to be adjusted manually frequently. It is rarely used now.
Hydraulic bulldozer: the blade acts under the action of hydraulic cylinder, which can be forced into the soil under the action of hydraulic cylinder, or the blade can be buried by its own weight. It can shovel and push hard soil, with excellent operation performance and good leveling quality. In addition, the blade is light in structure, easy to operate, and the control mechanism does not need manual adjustment. The lifting and lowering speed of hydraulic blade is stable, which is more significant in winter.