The rolling resistance of 4wd tractors is mainly due to the deformation of the tires and soil. Under the heavy pressure of the 4wd tractor, the tires are flattened and the soil is compacted. During the rolling process of the wheel, the various parts of the tire that come into contact with the ground along the circumferential direction subsequently undergo flattening deformation, while the soil pressure in front of the wheel is downward, causing deformation and forming wheel ruts.
This is known as rolling resistance, which prevents the wheel from rolling forward. There are many factors that affect rolling resistance, mainly related to factors such as ground firmness and the degree of moisture in vertical loads. For the same 4wd tractor, if the ground conditions are different, its rolling resistance will also be different. For example, when driving on asphalt cement or dry and hard ground, the rolling resistance is small, and the traction force of the 4WD tractor is large.
Under the same usage conditions, if a large weight is added to the tires, the vertical deformation of the soil will also be large, and the rolling resistance will also be large. Generally speaking, reducing the deformation of the tire itself and the vertical deformation of the soil is beneficial for reducing rolling resistance.
If a 4WD tractor operates on soft ground, using low-pressure tires and increasing the tire support area can reduce soil deformation in the vertical direction, reduce rolling resistance, and thus improve traction. Due to the fact that 4WD tractors are mainly used for field work and often run on soft ground to reduce soil deformation in the vertical direction, these 4wd tractors generally use low-pressure tires, and the use of widened tires is also the same reason. In our business, we should pay attention to the differences in the use of low-pressure tires, widened tires, and high-pressure tires.