Hydrodynamic retarder has a controlled fluid level at lower speeds by removing fluid via impulses applied to the fluid

摘要

A hydrodynamic retarder has a stator (5) and a rotor (7) at a set spacing (d) and with the stator cavity drained via an outlet (11) into a stator chamber (13). To remove fluid from the retarder when operating at low speeds, or running at idling speed, pressure pulses are applied to the trapped hydraulic fluid causing a non return valve to vent excess fluid. The lower level of fluid greatly reduces the drag of the retarder for normal running.