MAN Truck & Bus


Grafik Retarder
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Section of a Voith retarder 1) drive shaft 2) rotor 3) stator 4) heat exchanger 5) central oil drain 6) oil reservoir.

Retarders are used to further improve the braking performance on commercial vehicles. Like engine brakes, they are wear-free continuous brakes. Retarders relieve the service brake and increase the active safety and cost-effectiveness of commercial vehicles. Retarders are installed in a commercial vehicle's drive train. They convert some of the vehicle's kinetic energy into heat. Subject to installation location, a distinction is made between primary retarders (depend on engine speed and installed between engine and transmission) and secondary retarders (speed-dependent and installed between transmission and drive axle). After operation and structure, a further distinction is made between hydrodynamic retarders (hydrodynamic brakes) and electrodynamic retarders. Hydrodynamic secondary retarders are normally used in modern forward control trucks. The braking effect depends on vehicle speed