6.1.1 Purpose of the chassis
There is a body and there are wheels (propellers, if in a scientific way). The question arises: how to connect the wheels to the car body, so that it is possible to drive a car, continuously transmit the traction from the engine to the drive wheels and at the same time comfortably overcome all the unevenness of the roads with various surfaces and without pavement? In this case, the connection of the wheels with the car body must be sufficiently rigid so that the car, while performing any maneuvers, simply does not turn over. The answer is simple - install the wheels on the intermediate link. A suspension performs a function of such a link.
Suspension elements should be as light as possible and provide maximum isolation from road noise. In addition, it should be mentioned that the suspension transmits the forces arising from the contact of the wheel with the road to the car body. Therefore, it is designed in such a way that it has increased strength and durability (see figure 6.1).
Figure 6.1 Forces on the wheel when it’s moving on the road.
Due to the high requirements for the suspension, each of its elements must be designed according to certain criteria, namely: the hinged joints used should easily rotate, but at the same time be sufficiently rigid and provide noise insulation for the car body; levers must transmit the forces arising from the operation of the suspension in all directions, as well as perceive the forces that arise during braking and acceleration; however, they should not be too heavy or expensive to manufacture.