As in passenger cars, the global trend in commercial vehicles is clearly moving towards disc brakes. The result is that the demand for drum brakes is limited to special applications, such as construction and off-road vehicles. Disc brakes exert deceleration due to friction: b equipped with brake pads are pressed against the brake disc that is attached to the wheel – using the same principle as the traditional rim brake on a bicycle.
Depending on arrangement of the brake pistons required for the contact pressure, a distinction is made between so-called fixed and floating caliper disc brakes. Floating caliper disc brakes are mainly used today due to their low space requirement and weight and their (comparatively) simple production.
Disc brakes are lighter and offer even further advantages compared to drum brakes. The pads can be replaced more quickly, the braking effect can be regulated more precisely and the tendency towards fading is much lower. The latter is due above all to better cooling resulting from the open design. Internally ventilated brake discs, which are the norm on commercial vehicles, further reinforce this positive effect.
A focus on weight and service
Disc brakes are dimensioned differently depending on axle load, rim diameter and required braking torques for trailers, semi-trailers, trucks and buses. In the past, practically all brake manufacturers were able to continue reducing the inherent weight of the brakes while maintaining the same stability. A further feature of this continuous development is the important matter of service friendliness, above all the use of pads, calipers and other components like guide bolts and adjusting screws that are easy to replace.