Multi - Link Suspension

Multi-link suspension on the 2010 Mercedes-Benz E- Class

Multi-link suspension was first developed by Mercedes-Benz in 1982 for the 190 series.
Driven and non-driven multi-link front and rear suspensions have been used. Up to five
links are used to control wheel forces and torque depending on the geometry, kinematics,
elastokinematics and force application of the axle. As the arrangement of links is almost
a matter of choice depending on the amount of available space.


Advantage :

• Free and independent establishment of the kingpin offset, disturbing force and torquedeveloped by the radial force.
• Considerable opportunities for balancing the pitching movements of vehicles during braking and acceleration (up to more than 100% anti-dive, anti-lift and anti-squat possible.)
• Advantageous wheel control with regard to toe-in, camber and track with width behavior from the point of view of tire force build-up and tire wear as a function of jounce with almost free definition of the roll center and hence a very good possibility of balancing the self-steering properties.

Disadvantage :

• Increased expenditure as a result of the high number of links and bearings; 
• Higher production and assembly costs; 
• The possibility of kinematic over-correction of the axle resulting in necessary deformation of the bearings during vertical or longitudinal movements;
• High requirements with regard to the observation of tolerances relating to geometry and rigidity.

Multi-Link

Multi-link rear suspension of the BMW 5 series (E39, 1996). Mainly aluminum is used for

the suspension system derived from the geometry of the BMW 7 series.

(1) The sub-frame (rear-axle support), produced from welded aluminum tubes, is attached to thebodywork by means of four large rubber mounts (2). These are soft in a longitudinal direction
for the purpose of riding comfort and noise insulation and rigid in a transverse direction to
achieve accurate wheel control.

The differential gear also has compliant mounts (3). The wheel carrier is mounted on a U-shaped arm (5) at the bottom and on the transverse link (7) and inclined guide link (8) at the top. As a result of this inclined position, an instaneous center is produced between the transverse link and guide link outside the vehicle which leads to the desired brake understeer during cornering and the elastokinematic compensation of deformation of the rubber bearings and components.

The driving and braking torque of the wheel carrier (11) is borne by the ‘integral’ link (9) on the swinging arm (5), which is subject to additional torsional stress as a result. This design makes it possible to ensure longitudinally elastic control of the swinging arm on the guide bearing (10) for reasons of comfort, without braking or driving torque twisting the guide bearings as would be the case with torque borne by pairs of longitudinal links. The stabilizer behind presses on the swinging arm (5) by means of the stabilizer link (6), whereas the twin-tube gas-pressure shock absorber, whose outer tube is also made of aluminum, and the suspension springs provide a favorably large spring base attached directly to the wheel carrier (11). For reasons of weight, the wheel discs are also made of aluminum plate. The wheel carrier is made of shell cast aluminum. The rear axle of the station wagon BMW Tourer is largely similar in design. However, the shock absorber extends from the U-shaped swinging arm in order to allow for a wide and low loading area.