Press Release
Chassis
Everything under control
- SBCâ„¢: high-pressure braking system with dual control unit
- Air suspension: AIRMATIC DC configured for unique levels of comfort
- Axles: double wishbones at the front, multi-link principle at the rear
- Braking system: two front brake calipers for exemplary performance
- Tires: automatic tyre pressure monitoring on the move
Safety, comfort, handling – three aspects that were writ large during the design
and development of the suspension system for the Maybach. To achieve these
aims the luxury brand uses trailblazing innovations introduced by its sister-brand
Mercedes-Benz, thereby also setting standards in the high-end luxury motor car
segment where suspension technology is concerned:
- Safety: In addition to large brake discs at both front and rear the new
Maybach is equipped with the electrohydraulic braking system
Sensotronic Brake Control (SBCâ„¢). The engineers in Sindelfingen
have developed this technology further for the Maybach and configured
it to meet the need for enhanced braking performance. Together with
ESP®, ASR, ABS and Brake Assist the Maybach therefore features the most advanced and efficient dynamic control systems.
- Comfort: The electronically controlled air suspension system
AIRMATIC DC (Dual Control) enables the luxury car to achieve a new
dimension in ride comfort.
- Handling: The Maybach proves that a large, high-prestige motor car
can also be outstandingly agile and dynamic. This is in large measure
2 due to AIRMATIC DC with its automatic, situation-related adaptation of
spring and shock absorber stiffness and the sophisticated design of the
axles.
AIRMATIC DC: a combination of air suspension and adaptive damping
The suffix "DC" stands for "Dual Control" and refers to the dual function of
AIRMATIC: the system combines an actively controllable air suspension with the
Adaptive Damping System (ADS II), thereby influencing both springing and
damping in equal measure. ADS II regulates the shock absorber force depending
on the road surface, driving style and vehicle load, while rubber bellows filled with
compressed air at the axles ensure comfortable springing in the luxury motor car.
The system in the Maybach operates at a pressure of six to ten bar.
AIRMATIC DC controls the air volume in the rubber spring bellows depending on
the driving situation. On rapid bends or under similarly high dynamic loads, for
example, the air suspension briefly deactivates part of the air volume it contains
and thereby stiffens the spring action to reduce body roll and pitching. During
normal driving the entire air volume remains active, providing soft springing and
maximum comfort.
This situation-related activation and deactivation of what is termed the comfort air
volume and the automatic adjustment of shock absorber stiffness are the result of
a practically instantaneous calculation process (algorithm) during which the microprocessor compares current sensor data for the steering angle, linear and lateral
acceleration and vehicle attitude with specified values stored in a memory.
The Adaptive Damping System (ADS II) supports these control processes with the
so-called Skyhook algorithm. This allows the damping forces at each wheel to be
regulated within less than 0.05 seconds so that the forces acting on the vehicle
body from the wheel movements are noticeably reduced. During a braking
maneuver, for example, the system increases suspension compression at the
front axle and rebound at the rear axle, reducing the tendency of the body to dive.
To make this lightning-fast intervention possible, the shock absorbers of the
Maybach are equipped with electrically operated solenoid valves which separately
influence the compression and rebound of each wheel according to the situation
and its requirements.
In addition the driver is able to adjust the spring rate and damping himself at the
touch of a button. There is a choice between a comfort-focused basic settings
(switch position 0) and two positions with tauter spring and damper settings. In
switch positions 1 and 2 AIRMATIC DC lowers the vehicle body by 15 millimeters –
usually automatically when the speed reaches 140 km/h – to reduce wind
resistance and improve handling stability. Below 70 km/h the body is raised to its
normal level again.
In addition to the air springs with their newly-developed, particularly thin-walled
and harshness-optimized rubber bellows, the ADS II shock absorbers and the
control unit, AIRMATIC DC includes various components which are mainly
responsible for a rapid build-up of pressure and reliable pressure storage:
- The pressure supply unit consists of an electrically powered compressor with a regenerative drier and a valve unit.
- The distribution block features the pressure reservoir charge valve, a central pressure sensor and the connectors for the pneumatic lines.
- The two reservoirs maintain a charge pressure of up to 16 bar which the
system uses when at rest or at low speed to ensure a rapid and noiseless self-leveling
effect.
- Two sensors on the front axle and one on the rear axle monitor the level of the vehicle body. In addition, the AIRMATIC control unit receives signals from three
acceleration sensors on the bodywork and a steering angle sensor.
Front suspension: double wishbones and an efficiently isolated subframe
In view of the outstanding performance and weight of the Maybach the choice by
the development engineers naturally fell on a double wishbone front suspension.
This design meets all the requirements for this unique luxury motorcar while
providing a low level of road roar and tire vibration. It consists of forged steel and
aluminum components, the lower wishbone being of forged steel and the upper of
aluminum.
Wheel location is via two control arms on each side: the upper wishbone is directly
connected to the body via large rubber mountings, while the lower wishbone
supporting the air suspension spring strut is attached to a large sheet steel
subframe, also via rubber mountings, which is in turn isolated from the body by
four hydraulically dampened bearings. This technology makes a major contribution
to the high vibration comfort of the Maybach.
Steering: a system with many comfort benefits
In the case of the steering the engineers likewise opted for the system that offers
the most comfort benefits with the front axle load and steering forces of the
Maybach, namely recirculating-ball steering.
This operates with speed-sensitive power assistance and has an electronically
controlled regulating valve to reduce the steering effort from approx. five Newton
meters on fast roads to only approx 2.5 Newton meters when parking or
manoeuvring at low speeds. The design features an inner and outer jacket tube
which can be moved relative to each other via a spindle, enabling the steering
wheel to be individually adjusted for reach from the normal position by up to 21
millimeters to the front and up to 35 millimeters to the rear. The driver need only
operate a lever adjacent to the steering column and an electric motor carries out his
wishes. The same applies to the height adjustment by up to 35 millimeters upwards
and a maximum of 13 millimeters downwards. This adjustment is carried out by a
further electric motor, a gear and two lifting spindles -- a high level of technical
sophistication for maximum individual comfort.
The rim of the steering wheel (diameter 384 millimeters) is covered in fine leather
and wood and is of die cast aluminum.
SBCâ„¢: electrohydraulic braking system with eight circuits
The introduction of Sensotronic Brake Control (SBCâ„¢) by Mercedes-Benz in 2001
began the company's entry into the world of so-called "by wire" systems, which no
longer transmit the driver's commands mechanically or hydraulically, but
electronically by cable. Maybach has benefited from the technological lead of its
sister-brand and equips its high-end luxury motor car with a further development of
the SBCâ„¢ system.
By contrast with the Mercedes-Benz SL and E-Class, which are likewise equipped
with SBC, the system in the Maybach has two central control units, two high-pressure
reservoirs, two hydraulic units and therefore a total of eight brake circuits. In this way, the engineers have done justice to the higher hydraulic volume requirement of the larger braking system in the Maybach.
The two powerful microprocessors interact constantly and control all braking
processes. When the driver depresses the brake pedal, sensors register the
pressure and speed of pedal operation and transfer this information to the control
units to initiate an almost instantaneous and highly dynamic brake management
process. At the same time the SBCâ„¢ microprocessors are also receiving sensor
signals relating to the current driving situation from other electronic assistance
systems, and are therefore able to adapt the braking command precisely to the
actual conditions for optimal deceleration and handling stability. During the
process SBCâ„¢ individually calculates the brake force for each wheel.
The brake fluid in the two high-pressure reservoirs is under a constant, high
pressure of 140 to 160 bar, which guarantees the extremely short response times
of this innovative braking system. The microprocessors regulate this pressure to
suit the requirements, and also control the electric pump connected to the
reservoir. The eight pressure modulators in the hydraulic units transfer the braking
pressure to the wheels, with two responsible for each wheel. In this way the
commands from the electronic control units can be precisely implemented at each
wheel.
The extremely dynamic build-up of pressure and precise monitoring of driver and
vehicle behaviour by means of a sophisticated sensor system are the greatest
advantages of this unique braking system and significantly improve handling
safety. During emergency braking, for example: SBCâ„¢ even recognizes a rapid
movement of the driver's foot from the accelerator to the brake pedal as an
indication of an emergency situation and responds automatically. With the help of
the high-pressure reservoir the system increases the pressure in the brake lines
and immediately brings the brake linings into light contact with the brake discs,
ensuring that they are able to exert their full pressure at once when the brake
pedal is operated.
SBCâ„¢ also improves handling safety in other respects, as the system works
together with other control systems in the Maybach via a databus:
When skidding is imminent SBC™ supports the Electronic Stability Program ESP® and ensures extremely rapid, finely metered braking impulses which reliably and
comfortably stabilize the vehicle.
When braking on bends the variable brake force distribution actively influences
the oversteer and understeer characteristics if the car: SBCâ„¢ enables the brake
pressure to be metered in such a way that it is automatically increased at the outer
wheels, transferring greater brake forces as a result of larger tyre contact forces.
At the same time the brake forces at the inner wheels are reduced in favor of the
lateral stabilizing forces which are important for directional stability. The result is
more stable braking behavior with optimal deceleration values.
In wet conditions Sensotronic Brake Control removes the film of water from the
brake discs by briefly applying the brake linings at regular intervals, thereby
ensuring that the system can operate with full efficiency at all times. This
automatic brake-drying function is activated when the windscreen wipers have
been in operation for a certain time. The finely metered braking impulses are not
noticeable to the driver.
Mechanically isolating the SBCâ„¢ brake pedal from the remaining braking system
together with proportional pressure control improves comfort when braking –
especially during heavy deceleration or when the anti-lock braking system is
activated. The pulsing usually felt in the brake pedal during ABS intervention no
longer occurs.
The Soft-Stop function is another comfort-enhancing feature of the braking
system. This enables the vehicle to be brought to a particularly gentle stop, e.g. in
city traffic with frequent traffic lights. This is made possible by finely metered
pressure control, as SBCâ„¢ reduces the brake servo pressure shortly before the
vehicle comes to a halt and thereby prevents the characteristic jerk frequently felt
when braking to a stop. The Soft-Stop function is always active – the system only
gives priority to rapid deceleration during emergency braking or during slow
maneuvers.
Braking system: ready for any challenge with six brake calipers
An exceptionally powerful and imposing luxury motor car requires an equally
exceptional braking system. SBCâ„¢ is a highlight, which makes the new Maybach
something special in this area, and this system is complemented with large,
internally ventilated front disc brakes, each of which features two brake calipers.
This means that a remarkable 248 square centimeters of brake lining surface are
available to decelerate this high-end luxury car safely and reliably.
The rear axle is equipped with four-piston, fixed-caliper brakes with a total lining
surface of 124 square centimeters. The front and rear brake discs are of cast iron,
the calipers of die cast aluminum.
Rear suspension: redesigned multi-link independent suspension
The well-proven multi-link independent rear suspension used in Mercedes models
also ensure precise wheel location and a high level of rear suspension comfort in
the Maybach. Almost all the components of this sophisticated five-link system
have however been newly developed for the Maybach.
The radius rods and camber arms as well as the track rods are of forged steel,
while the spring links are of sheet steel. The axle carriers are two tubular steel
sections connected by two cross-members (sheet steel) and isolated from the
vehicle body by hydraulically dampened bearings. The control arms have their
mounting points on the sides of the axle carriers and likewise feature large rubber
bearings.
Wheels and tires: a majestic 19 inches
19-inch tyres accentuate the imposing appearance of the Maybach luxury
automobile, which is equipped with attractive, cast light-alloy wheels as standard.
The wheel size is 8 J x 19 ET 67, while tires are of size 275/50 R 19. On request
the wheels can be fitted with a run-flat feature in the form of a steel supporting
ring which allows a defective tire to continue running. The innovative tire sealing
kit TIREFIT is standard equipment in the Maybach – a fully-fledged spare wheel is
available at no extra cost as an alternative.
An electronic control system which constantly monitors the tire pressures is also
provided as standard. This function is performed by sensors in the four tire valves
which measure both the inflation pressure and inside temperature of each tyre.
These data are usually transmitted to special antennae in the wheel arches by
radio once every minute, then transferred to a microprocessor by cable. This
evaluates the signals from the four transmitters according to their different
identification codes and is therefore able to provide the driver with specific
information concerning the air pressure in each tire. The values appear in the
central display in the instrument cluster. In the event of a sudden and rapid
pressure loss in any of the tires an appropriate signal is immediately sent to alert
the driver in good time.