Patent ID: 7980980

Claim:
A hybrid powertrain comprising: an input member; an output member; an engine operatively connected with the input member; first and second electric motor/generators; a differential gear set having multiple members; selectively engageable torque-transmitting mechanisms; wherein at least some of the input member, the output member, the engine and the motor/generators are selectively interconnected through the differential gear set by engagement of different combinations of the torque-transmitting mechanisms; an electronic controller operatively connected to the electric motor/generators and configured to control the electric motor/generators to provide multiple operating modes between the input member and the output member, including: a first electric-only operating mode in which the engine is off, one of the first and second electric motor/generators acts as a motor to provide torque at the output member while the other of the first and second electric motor/generators is not connected to any of the members of the differential gear set and is able to remain substantially stationary; and a second electric-only operating mode in which the engine is off and both first and second electric motor/generators act as motors to provide torque at the output member; and wherein the engine is not continuously connected to any of the members of the differential gear set and is selectively connectable for common rotation with the second motor/generator by engagement of one of the torque-transmitting mechanisms.