Multi-link suspension

(Also called multi- link axis) The multi-link suspension is a suspension often used on the rear axle, but also at the front of car with three to five links per wheel behind the term refers to a plethora of possible or actually exported constructions. Complicating the overview is vendor- specific names. Together the effort, the spatial movement of the wheel is to be designed so that as many criteria are met in the design.

In the multi-link suspension is one or both of the wishbone otherwise often used in single handlebar dissolved. In the base form of five individual links ( support rod ) can be used for each wheel, the steering knuckle and to the vehicle body (or the fixed body subframe ) are mounted at a respective point of a ball joint or rubber stock. Each of these links takes the knuckle one of the six degrees of freedom of a body in space, so that just remains a degree of freedom for compression and rebound. Example of this embodiment, the multi-link axle of Mercedes -Benz.

This design offers over conventional axles more ways to the change of camber and toe depending on the compression and the forces acting ( elasto ) vote. The pole position of the handlebar extensions can be put in contrast to A-arms in the wheel center plane or beyond. If the pole of two links in the midplane of the wheel, a lever arm can be realized for the zero acting on the wheel forces. Due to the structural design, a targeted steering behavior of the wheel can be achieved ( for example, a tendency towards toe- in drive forces). It is also possible to allow at any longitudinal forces a parallel displacement of the wheel center. A toe-in can be avoided.

The multi-link axle was of Mercedes -Benz W201 in the series ( " 190 "), first used in 1982 and is a Mercedes -Benz innovation. To date, a modified version of the multi-link axle found in the current models of the brand. Copied and modified forms of this construction can now be found in many models from other car manufacturers.

As the front axle design of a five - link axle is much more complex than on the rear axle as a result of the additional wheel lock. At Audi models and the VW Passat was nevertheless implemented and is there referred to as " four-link suspension ". However, the counting expects the tie rod not to the handlebars.

Other types

If the knuckle housing the upper arm above the wheel center plane, a wishbone, instead of the two upper wishbones are used (as in the picture). Here, the rear lower control arm is usually mechanically adjustable to set the correct toe-in can. In the illustrated case, a very precise guiding of the fall is ensured by the lying far above wishbone. This design can also be on the front axle - used - but with a different geometry. Here the term 4- link axle is common because of the wishbone is counted as one link.

In the spherical double -wishbone axle, the trailing arm rigidly connected to the wheel support is supported with two cross- links. The trailing arm is connected by a spherical joint with the structure. All points of the wheel move on spherical surfaces around this joint. The shaft has only one degree of freedom, can therefore be used as a rear axle. At BMW, the axis is called a central-arm rear axle.

If the fifth link designed as a coupling link between two other drivers, the result is the integral link suspension, which is used in the BMW 5 Series and 7 Series as a rear axle. Connects the coupling link the trapezoidal-link (variant of the wishbone ) to the wheel, the result is the trapezoidal-link axle, which is used as rear axle application in 7 Series models from BMW or Audi.

As the combination of a front wheel- strut is used with a broken lower wishbone at BMW and Mercedes. With the tie rod as the third support rod, this creates the spring or damper strut suspension. By resolution of the wishbone an ideal expansion axis ( steering axis) is achieved. The same principle is used with a different geometry as a rear axle. Example is the Camuffo rear axle.

For vehicles with powerful engines with front wheel drive, Ford developed a variant of the MacPherson - axis under the name RevoKnuckle axis. Advantage is the very small disturbing force lever arm, so one-sided driving forces have little effect on the steering. At General Motors, this principle is referred to as " HiPer Strut suspension".