Hydrodynamic coupling apparatus

A hydrodynamic coupling apparatus (10) for transmitting torque between driving elements (26) by dynamic fluid action, the apparatus (10) 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) supported by the case (12);
• an impeller (34) 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 turbine (36) rotatably supported in the clutch housing (24) adjacent the impeller, a magnetorheological fluid (30) disposed in the clutch housing (24) and between the impeller and the turbine, the impeller (34) having blades configured to rotate the turbine by propelling magnetorheological fluid (30) against blades (40) of the turbine (36);
• and
• 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 the flux density of the magnetic field;
• and
• the field generator (32) is further positioned such that the magnetic field crosses and is localized at the turbine, localizing viscosity changes in the magnetorheological fluid adjacent the turbine and allowing relatively lower fluid viscosities to exist in the magnetorheological fluid adjacent the impeller.

A method for transmitting torque between driving and driven elements by dynamic fluid (30) action, the method including the steps of:

• providing a hydrodynamic coupling apparatus (10) comprising an input shaft (14) having a first end (16) rotatably supported within a clutch housing (24), an impeller (34) carried by the input shaft (14) within the clutch housing (24), and a turbine (36) rotatably supported in the clutch housing (24) adjacent the driving element (26) and operably connected to an output shaft (42);
• providing magnetorheological fluid (30) in the clutch housing (24) and between the driving element (26) and the driven element (28);
• providing an electromagnetic field generator (32) adjacent the magnetorheological fluid;
• applying torque to the output shaft (42) by rotating the turbine (36) by propelling magnetorheological fluid (30) against blades of the turbine (36) by rotating the impeller (34) by applying torque to the input shaft (14);
• and
• adjusting the proportion of torque passed from the input shaft (14) to the output shaft (42) by changing the viscosity of the magnetorheological fluid (30) by causing the field generator (32) to change the magnitude of the electromagnetic field.

A method for dampening vibration including the steps of:

• providing a hydrodynamic coupling apparatus (10′) in a drive train, the apparatus (10′) comprising an input shaft (14′) having a first end (16′) rotatably supported within a housing and carrying an impeller (26′), and a turbine (28′) supported in the housing adjacent the impeller (26′);
• providing magnetorheological fluid (30′) in the housing and between the impeller (26′) and the turbine (28′);
• providing an electromagnetic field generator (32′) adjacent the magnetorheological fluid;
• providing a sensor (78), (80), (82) at a desired sensor location in the drive train;
• providing a controller (74) and connecting the controller (74) to the sensor and to the field generator (32′);
• applying torque to the input shaft (14′) to rotate the driving element (26′);
• countering a torque oscillation, pulse, or vibration detected at the sensor location by causing the controller (74) to energize the coil (62′) in response to a corresponding signal received from the sensor;
• and
• positioning the field generator such that its magnetic field crosses and is localized at the turbine, localizing viscosity increases in the magnetorheological fluid adjacent the turbine and allowing relatively lower fluid viscosities to exist in the magnetorheological fluid adjacent the impeller.