Patent ID: 8479896

Claim:
A hydrodynamic retarder comprising: a rotor blade wheel comprising: a first base body defining a plurality of receptacles; a first plurality of blades; first blade tangs connecting at least some of the first plurality of blades to respective receptacles in the first base body; and a stator blade wheel comprising: a second base body defining a plurality of receptacles; a second plurality of stator blades, concentric to the rotor blade wheel, the first blade wheel and the second blade wheel grouped around a common axis of rotation to form a hydrodynamic circuit; second blade tangs connecting at least some of the second plurality of blades to respective receptacles in the base body; wherein one of the rotor blade wheel and the stator blade wheel further comprises: a first ring segment comprising at least one first blade having a flow edge facing the other blade wheel, the flow edge having a radially outer end and a radially inner end, the flow edge extending in a substantially straight line between the radially outer end and the radially inner end; and a second ring segment comprising at least one second blade, the at least one second blade comprising a setback from: a flow edge facing the other blade wheel and a projection projecting toward the rotor blade wheel; wherein the setback between the radially outer end of the flow edge and the projection is curved and essentially arc-shaped, the setback merging in an at least essentially continuous manner with at least one of the flow edge and the projection, and the second ring segment extends between an outlet area assigned to the fluid supply and a control area of the rotor or stator blade wheel.