The Voith Aquatarder is installed at the engine front end and directly connected with the engine crank shaft. It therefore belongs to the category of primary retarders.
In tractive operation, the volume flow created by the water pump is guided directly to the engine, by-passing the Aquatarder circuit. Every braking command activates the switch valve, so that the volume flow of the water pump is directed 100% into the retarder circuit. From there, further transport of the flow is taken over by the retarder, because it acts like a strong pump itself. In order to achieve the desired braking power with this pump performance, the retarder needs to act against an outlet resistance. This throttling point is a pneumatic outlet control valve which enables the stepless control of the braking torque.
When the retarder is switched off, the two valves are ventilated and put back into their starter position. Consequently, the switch valve allows the cooling water to by-pass the retarder, while the retarder is draining against the power of the shut-down outlet valve. |
