Annual Report 2012 - Knorr-Bremse AG.

Report
69
Differential lock for commercial vehicles assists truck drivers
Drivers sometimes find it difficult to decide when to activate the differential lock and when it is
better not to. The result is that it is often switched on too late, when the vehicle has already stopped
moving or one wheel is already spinning so much that the differential lock no longer engages. The
so-called Differential Lock Control system developed by Knorr-Bremse helps the driver by activating
the lock on solo and tandem rear axles and automatically deactivating it again as soon as it is no
longer required.
If one or more wheels start to spin, the system applies the brake to the spinning wheel(s) to synchronize
the axle concerned, and then automatically activates the differential lock. To speed up
the process, ensure rapid activation and minimize wear, the drive train may also be briefly disengaged.
New ST7-430 trailer brake boosts efficiency in trailers too
The new ST7-430 brake literally lightens the load for trailers. This successor to the successful SK7 is
one of the lightest two-piston disc brakes for 22.5-inch wheels on the market. The ST7-430 is designed
for 9-tonne trailer axles and thanks to its optimized disc and caliper weighs in at around four
and a half kilograms less than its predecessor. This means that for a classical trailer application the
unladen weight is reduced by 27 kg. The fact that this enables the load volume to be increased is, if
you take a mineral oil tanker as an example, a strong argument for purchasing the system. And if the
full load capacity is not used, the 27 kg saved will certainly reduce fuel consumption. Thus either
way, trailer efficiency can be increased. During 2012 prototype testing was completed and preparations
made for customer field testing.
Compressor development for hybrid applications
There are still many unanswered questions about how truck hybrid applications can be used effectively
in the medium and long term, but one thing is clear: sooner or later such modern drive systems
are going to be found in this segment. It is also clear that the compressors used to generate air for the
braking system will no longer be powered by the vehicle’s combustion engine, as – depending on
the type of system involved – it temporarily switches off during hybrid operation. And, of course in
the case of fully electric vehicles, the combustion engine will cease to exist completely. Hence the
need to look to the future and develop an electrically-powered compressor.
The new electrically-powered
compressor
is designed for
maximum flexibility
and can be installed
in a wide range of
hybrid vehicles.
During the year under review, Knorr-Bremse started to work on a prototype electric compressor that
is also oil-free and air-cooled, as current compressors are not just mechanically linked to the vehicle’s
combustion engine but also share its oil- and water-cooling system. The new compressor is completely
separate from the drive system and can be installed anywhere in the vehicle as a stand-alone,
battery-powered component. Knorr-Bremse sees the main use of hybrid drive systems as being on
urban buses and local distribution trucks, so the new battery has been designed to be highly flexible
and capable of installation in a wide variety of different vehicle types. At the same time the emphasis
during the development stage was on noise and vibration reduction.
Volume production launched of new slack adjusters for disc brakes
Slack adjusters are essential elements of any disc brake, as they ensure that the running clearance
between the brake pads and disc remains constant, however much wear the pads are exposed to.
During 2012 Knorr-Bremse successfully launched volume production of its new N2G slack adjuster.
These will initially be installed on semi-trailer tractor units, and in 2013 will be rolled out for the entire
range of disc brake applications including truck trailers.