Patent ID: 7252614

Claim:
An electrically variable transmission comprising: an input member to receive power from an engine; an output member; first and second motor/generators; first, second and third differential gear sets each having first, second and third members; said input member being selectively connected with at least one member of said gear sets, and said output member being continuously connected with at least one member of said gear sets; a first interconnecting member continuously connecting said first member of said first gear set with said first member of said second gear set; a second interconnecting member continuously connecting said second member of said second gear set with said first member of said third gear set; a third interconnecting member continuously connecting said second member of said first gear set with said second member of said third gear set or with a stationary member; said first motor/generator being continuously connected with a member of said first or second gear set; said second motor/generator being continuously connected with a member of said first, second or third gear set, said member being different from said member continuously connected with said first motor/generator; a first torque transfer device selectively connecting a member of said first, second or third gear set with said input member; a second torque transfer device selectively connecting another member of said first, second or third gear set with said input member; a third torque transfer device selectively grounding a member of said first, second or third gear set; a fourth torque transfer device connected in parallel with one of said first and second motor/generators for selectively preventing rotation thereof; a fifth torque transfer device connected in parallel with the other of said first and second motor/generators for selectively preventing rotation thereof; and wherein said first, second, third, fourth and fifth torque transfer devices are engageable alone or in combinations of two or three to provide an electrically variable transmission with a continuously variable range of speed ratios and up to four fixed forward speed ratios.