Page 226 - Automotive Engineering Powertrain Chassis System and Vehicle Body

CH AP TER 8 .1 Types of suspension and drive

Fig. 8.1-41 Front axle of the Mercedes-Benz Sprinter series (1995). The wheel-controlling strut is screwed on to the wheel carrier,
which is, in turn, connected to the lower cross-member by means of a ball joint. Both the vehicle suspension and roll stabilization are
ensured by means of a transverse plastic leaf springmounted on rubber elements. Large rubber buffers with progressive rigidity act
as additional springs and bump stops.

and it drives the rear wheels. The power plant can sit
behind the axle (Fig. 8.1-45, rear-mounted engine) or in
front of it (Fig. 8.1-46, central engine). This configuration
makes it impossible to have a rear seat as the engine
occupies this space. The resulting two-seater is only
suitable as a sports or rally car.
The disadvantages of rear and central engine drive on
passenger cars are:

moderate straight running abilities (caster offset at

ground angles of up to s ¼ 8 are factory set);
sensitivity to side winds;
indifferent cornering behaviour at the stability limit
(central engine);
oversteering behaviour on bends (rear-mounted
engine, see Fig. 10.1-42);

Fig. 8.1-42 Driven rear axle with air springs of the Mercedes-
Benz lorry 1017 L to 2219 L 6 2. The axle is carried in the
longitudinal and lateral directions by the two struts 1 and the
upper wishbone type control arm 2. The four spring bellows sit
under the longitudinal frame members and, because of the twin
tyres, they have a relatively low effective b Sp . The tracking width
b r divided by b Sp yields approximately the ratio i 4 ¼ 2.2.
To reduce body roll pitch the anti-roll bar 3 was placed
behind the axle and is supported on the frame via the rod 4.
The four shock absorbers 5 are almost vertical and are
positioned close to the wheels to enable roll movements of
the body to fade more quickly.

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