Method of controlling clutches in a multi-function torque converter

A method of controlling a multi-function torque converter including a cover arranged to receive torque, an impeller including an impeller shell and at least one impeller blade connected to the impeller shell, a turbine including a turbine shell and at least one turbine blade connected to the turbine shell, a first pressure chamber at least partially formed by the turbine shell and the cover;

• a second pressure chamber at least partially formed by the impeller and turbine shells, and a third pressure chamber at least partially formed by the impeller shell and the cover, an impeller clutch including a portion of the impeller shell, and a turbine clutch including a portion of the turbine shell, the method comprising:
• pressurizing the first pressure chamber to substantially a first fluid pressure level or to a second fluid pressure level greater than the first fluid pressure level;
• pressurizing the second pressure chamber to a third fluid pressure level greater than the first and second fluid pressure levels;
• passively draining the third pressure chamber to be substantially at the first fluid pressure level;
• and,
• connecting the impeller shell to the cover for a torque converter mode.

A method of controlling a multi-function torque converter including a cover arranged to receive torque, an impeller including an impeller shell and at least one impeller blade connected to the impeller shell, a turbine including a turbine shell and at least one turbine blade connected to the turbine shell, a first pressure chamber at least partially formed by the turbine shell and the cover;

• a second pressure chamber at least partially formed by the impeller and turbine shells, and a third pressure chamber at least partially formed by the impeller shell and the cover, an impeller clutch including a portion of the impeller shell and first friction material, and a turbine clutch including a portion of the turbine shell and second friction material, the method comprising:
• maintaining a substantially constant first fluid pressure force, in a first axial direction, on the impeller shell;
• applying a second fluid pressure force on respective first sides of the turbine and impeller shells in the first axial direction and in a second axial direction opposite the first axial direction, respectively;
• applying a third fluid pressure force to a second side of the turbine;
• displacing the impeller shell in the second axial direction;
• bringing the first friction material into contact with the cover and the portion of the impeller shell;
• and,
• independently rotating the turbine shell with respect to the impeller shell.