3 Axle Low Flatbed Semi Trailer Not Running Smoothly
Sometimes a 3 axle low flatbed semi trailer feels unstable when driving for a long time, which can be related to the road trailer itself. Let’s talk about the possible reasons for the instability of the 3 axle low flatbed semi trailer when driving:
The wheel plane is not perpendicular to the road surface
When a 3 axle low flatbed semi trailer is loaded, the axle shell and axle sleeve (or axle head) of the trailer can be deformed by load, which can lead to wheel inclination. At the same time, there is mounting clearance between hub, bearing and other parts or when driving in areas with large road falls, the phenomenon of wheel inclination can also worsen. If the wheel is not perpendicular to the road surface, the pressure distribution on the ground area is uneven, and the tire is in a rolling and sliding state while driving, resulting in tire wear. In this case, the wear on the inside of the tyre tread of the internal gearbox of the axle of the 3 axle low flatbed semi trailer is serious.
Unreasonable matching of structural parameters
The force acting on the tyre depends on factors such as load, road condition, driving speed and vehicle parameters.If the vehicle is driving on an uneven road, the tyre is subjected to a large dynamic load, and its value increases with the increase in load, road roughness, driving speed, suspension and wheel stiffness. Under the same operating conditions, the tyre will be protected from excessive impact loads if the structural parameters of the 3 axle low flatbed semi trailer are reasonably designed to have good damping properties. However, for the 3 axle low flatbed semi trailer produced by most domestic manufacturers, the middle truck rear suspension unit is basically selected for the suspension part, and the measures for adding sheets are also taken to increase the strength of spring separation. We believe that this combination does not well ensure the reasonable match of stiffness between semi-trailer frame, suspension and tire, so the 3 axle low flatbed semi trailer does not have good damping properties, which is one of the important factors to increase the dynamic load of tires and accelerate tire wear.
Whether the braking distribution is reasonable depends on the structural parameters and operating conditions of the 3 axle low flatbed semi trailer.Since the axle load of the semi trailer varies greatly between empty load and full load, the center of gravity of the semi trailer is high, and the load transfer during braking is large. Currently, the medium sized semi trailer produced in China is basically not equipped with brake force control. Therefore, it is difficult to ensure the requirements for the ideal characteristics of the vehicle’s braking force under non load and full load conditions simultaneously in the design. In general, it can only be designed according to the requirements of full load characteristics. In this way, the phenomenon of excessive braking of the trailer axle wheels occurs when the 3 axle low flatbed semi trailer is under non full load under emergency braking. When braking, the “locking” of the tire of the trailer axle often occurs, which accelerates the wear of its tread.
