Abstract: A powertrain includes an engine with an engine output member, such as a crankshaft, and a first motor/generator having a first rotor connected to the crankshaft for rotation therewith. A transmission includes a transmission input member, a transmission output member, and a differential gearing arrangement selectively operatively connecting the transmission input member and the transmission output member. A plurality of torque transmitting devices is selectively engageable to provide a plurality of fixed speed ratios between the transmission input member and the transmission output member. A second motor/generator includes a second rotor connected to the gearing arrangement to provide torque to the transmission output member. The transmission input member is selectively connectable to the engine output member and the first rotor to alternate between a series hybrid drive mode and a fixed ratio mode of powertrain operation. A corresponding method is also provided.

Abstract: The electrically variable transmission family of the present invention provides low-content, low-cost electrically variable transmission mechanisms including three differential gear sets, a battery, three interconnecting members, two electric machines serving interchangeably as motors or generators and five or six selectable torque-transfer devices. The selectable torque transmitting devices are engaged to yield an EVT with a continuously variable range of speeds and five fixed speed ratios, including four mechanically fixed forward speed ratios and one reverse speed ratio. The torque transmitting devices and the first and second motor/generators are operable to provide five operating modes in the electrically variable transmission, including battery reverse mode, EVT reverse mode, reverse and forward launch modes, continuously variable transmission range mode, and fixed ratio mode.