Hydrodynamic coupling

A flow controlled hydrodynamic coupling, comprising:

• a rotatable pump impeller;
• a drive shaft connected with the pump impeller for rotating the pump impeller;
• a turbine impeller spaced from the pump impeller;
• a driven shaft connected to the turbine impeller for being rotated by the turbine impeller;
• the pump impeller and the turbine impeller being so placed with respect to each other and so shaped as together to define a toroidal operating chamber into which the pump impeller and the turbine impeller communicate and into which operating medium may be filled for coupling the pump impeller to the turbine impeller by the operating medium;
• the operating chamber defined by the impellers having regions of greatest and lesser radius with respect to an axis of the rotation of the impellers;
• an outer circuit for supplying a fluid operating medium;
• a chamber inlet communicating from the outer circuit into the operating chamber;
• a housing surrounding and spaced out from the impellers, a housing inlet into the housing for receiving operating medium, and a housing outlet from the housing and spaced from the housing inlet for exit of the operating medium from the housing;
• and
• the inlet to the operating chamber being from inside the housing and past one of the impellers defining the operating chamber and being located at the region of greatest radius of the operating chamber.