The biggest advantage of wheeled chassis is low fuel consumption and easy to maneuver. Generally, its weight does not exceed 30T(8*8), so it cannot be loaded with heavy armor. Its passing performance is worse than that of crawler chassis, but it is easy to be transported by air (such as C 130 and Il 76) and its cost is relatively low.

Crawler chassis is generally a heavy armored vehicle or tank, which consumes a lot of oil and relies heavily on logistics, and its passing performance is better than that of wheeled vehicles. The requirement of air transportation is high, so it must be carried by heavy transport aircraft.

Crawler walking device is characterized by large driving force (usually the driving force of each crawler can reach 35%-45% of the machine weight) and low specific pressure (40- 150kPa), so it has good off-road performance and stability, and large climbing ability (generally 50%-80%, and the maximum driving force can reach 100%).

However, the crawler walking device has high manufacturing cost, low running speed, large power consumption during running and steering, and rapid wear of parts.

Compared with crawler-type walking device, tire-type walking device has the advantages of fast running speed, good maneuverability and no damage to the road surface during running, so it is very popular in urban construction. Disadvantages are high grounding pressure and low climbing ability.

Wheeled robot:

Advantages: high speed, high efficiency and low movement noise.

Disadvantages: poor obstacle crossing ability and terrain adaptability, low turning efficiency, or large turning radius.

Suitability: Both outdoor and urban environments are acceptable, but the terrain should not be too complicated, and it is difficult to climb stairs.

Crawler robot:

Advantages: Strong obstacle-crossing ability and terrain adaptability, and can turn in place.

Disadvantages: slow speed, low efficiency and loud movement noise.

Applicability: It can be used in outdoor and urban environment, especially for climbing stairs and crossing obstacles.

(1) crawler tractor

Because the crawler tractor is supported on the ground by the wound crawler, the contact area between the crawler and the ground is large and the pressure (unit area pressure) is small. For example, the grounding pressure of Dongfanghong -802 is 44. 1 kPa (0.45 kg/cm2), so the tractor is not easy to sink. Moreover, because there are many treads inserted into the soil, it is easy to grasp the soil layer, and it is not easy to slip on wet, muddy or soft soil, and it has good traction and adhesion performance. Compared with other types of tractors with the same power, it can send out more traction, so the crawler tractor has good adaptability to different ground and soil conditions, and can do heavy work such as land reclamation, deep ploughing and farmland infrastructure that other types of tractors cannot do. Its disadvantages are large and heavy volume, high metal consumption, high price and maintenance cost, few supporting agricultural machinery and tools, narrow working range, easy to destroy the road surface, and not suitable for road transportation. Therefore, the comprehensive utilization performance is low.

(2) Two-wheel drive wheeled tractor

Its characteristics are basically the opposite of crawler tractors. It has the advantages of small volume, light weight, less metal consumption and lower price and maintenance cost. There are many supporting agricultural machinery and tools, which can be used for road transportation, with long annual use time and high comprehensive utilization performance. The main production and sales of two-wheel tractors in China are large. Its disadvantage is that it has great pressure on the ground. In field operation, the tire pressure is generally 83.3 ~137.2kpa (0.85 ~1.4kg/cm2), which is hard.

The pavement is generally147 ~196 kpa (1.5 ~ 2.0 kg/cm2), so it is easy to get stuck. It is easy to slip on wet, muddy or soft soil, and the traction adhesion performance is poor, so it can't send out large traction. Therefore, when two-wheel drive wheeled tractors need large traction or poor road soil conditions (such as land reclamation, deep ploughing, farmland infrastructure, crossing road obstacles, etc.), the working quality is not as good as that of crawler tractors. )

(3) Four-wheel drive tractor

Its characteristics are between two-wheel drive wheeled tractor and crawler tractor, and it is a vehicle with both advantages. Because it is a four-wheel drive, the traction performance is 20% ~ 50% higher than that of a two-wheel drive tractor. It is suitable for hanging heavy or wide efficient farm tools, and also suitable for farmland capital construction. When working in moderate temperature soil, its working quality is similar to that of crawler tractor, but it is quite different when working in high humidity and cohesive soil. Structurally, it is more complicated and expensive than a two-wheel-driven wheeled tractor. But it consumes less metal and its price is lower than that of crawler bulldozers.

Power of various tractors:

The power of large tractors is greater than 73.6 kW (100 HP).

The power of medium tractor is14.7 ~ 73.6 kw (20 ~100 horsepower).

The power of small tractors is below 14.7 kW (20 HP).