Patent ID: 7070032

Claim:
A hydrodynamic coupling apparatus ( 10 ) for transmitting torque between driving and driven elements by dynamic fluid action, the apparatus comprising: a case ( 12 ); an input shaft ( 14 ) having a first end ( 16 ) rotatably supported within the case ( 12 ) and a second end ( 18 ) connectable to a torque generator ( 20 ); a hydrodynamic clutch ( 22 ) connected to the first end ( 16 ) of the input shaft ( 14 ) and including: a clutch housing ( 24 ) carried by the case ( 12 ); a driving element ( 26 ) fixed to the first end ( 16 ) of the input shaft ( 14 ) and rotatably supported with the input shaft ( 14 ) in the clutch housing ( 24 ); a driven element ( 28 ) rotatably supported in the clutch housing ( 24 ) adjacent the driving element ( 26 ), magnetorheological fluid ( 30 ) disposed in the clutch housing ( 24 ) and between the driving element ( 26 ) and the driven element ( 28 ); an electromagnetic field generator ( 32 ) positioned to generate a magnetic field in the magnetorheological fluid ( 30 ), the electromagnetic field generator ( 32 ) being adjustable to increase and decrease flux density of the magnetic field; and the driving element ( 26 ) including an impeller ( 34 ) and the driven element ( 28 ) including a turbine ( 36 ), the impeller ( 34 ) having blades configured to rotate the turbine ( 36 ) by propelling magnetorheological fluid ( 30 ) against blades of the turbine ( 36 ).