The main components that must adequately ensure reliability during operation, the required load capacity, ease of management of a variety of cargo trawls, trailers and semi-trailers are a high-quality frame base and an efficient suspension and axle system.
At the same time, the suspension system itself includes not only axles, but also spring elements, steering arms and other elements that very often fail in our difficult operating conditions.
All existing types of auto-suspensions are conventionally divided into two large categories:
Speaking of a dependent type, it is understood that the wheels of each continuous separate axis are fixed in a rigid bundle. In this case, the torque is transmitted from the engine through the bridge to all wheels simultaneously. The main disadvantage of such a system is the reaction to the problems (pits, bumps) of the road surface of two wheels at once, and not one.
A car with this type of suspension is quite difficult to drive, it requires an excellent response from the driver to the slightest changes in the movement of vehicles on bumps. Roughnesses in the road should compensate for dampers or springs in such situations. In this case, depending on the type of suspension can be used:
Any dependent suspension is characterized by poor sprungness of the entire body, strong shaking on road bumps, drifts during bends, and difficult handling of the car.
These suspension options are more variable in their execution. The drive for individual wheels is the semi-axis, which interacts with the chassis using a rather complex system of levers of longitudinal and transverse types. Suspension independence is expressed in the fact that each wheel reacts to road irregularities (bumps, pits) individually, while the general kinematics of the movement process is simpler and more predictable.
Over the decades, hundreds of variations of independent-type pendants have been invented, tested and released.
It does not make sense to list them all, because only a few options are most often used in modern automotive industry:
For a long time, the main type of suspension for this type of vehicle was the dependent suspension on springs. Over time, the tasks facing the carriers became more complicated, the dimensions and weight of the cargo increased. This required the search for new, more efficient and reliable systems in management. Today, dependent suspension on springs in trawls, if it is found, is quite rare.
The main types of suspension in our time are:
As practice shows, the most common steel suspension using pneumatics. Off-road high-frame semitrailers are most often equipped with spring-balancer suspension. Special reinforced pneumatic suspension systems can also be used here.
One of the expected innovations is the hydraulic suspension type, which are equipped with semi-trailers of all lines. The hydraulic system is controlled by “smart electronics”, which minimizes the impact on the parameters of movement of the road terrain.
She constantly monitors all the features of the coating, if necessary, increasing the angles of rotation of the axes and varying the clearance (ground clearance). With such a system, it is simple enough to go through even the coolest turns.
One of the important points when testing the strength of the frame and axles is the loading of a heavy load – self-propelled equipment. Here, the critical point is tensile loads of tens of tons of the rear trawl truck, which experiences maximum impact.
It is for this reason that the trawls for transporting self-propelled equipment are additionally reinforced in the rear. In addition, appropriate ladders for arrival are selected, which may differ in carrying capacity, material, type of execution.
Existing norms and standards for heavy equipment, multi-axle trucks, semi-trailers, trailers include strict requirements for maximum axle loads. The design of modern semi-trailers includes special gauge sensors that allow you to avoid quite substantial fines for exceeding the permissible loads on the roadway.
