Electrically variable transmission having three interconnected planetary gear sets, two clutches and at least two brakes

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 continuously connected with at least one member of said gear sets, and said output member being continuously connected with another 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 first gear set with said first member of said third gear set;
• a third interconnecting member continuously connecting said second member of said second gear set with said second member of said third gear set;
• said first motor/generator being continuously connected with a member of said first, second or third gear set;
• said second motor/generator being continuously connected with a member of said first, second or third gear set which is different from said member continuously connected with said first motor/generator;
• and
• first, second, third and fourth torque transfer devices for selectively interconnecting said members of said first, second or third gear sets with a stationary member or with other members of said planetary gear sets, said first, second, third and fourth torque transfer devices being engageable alone or in pairs to provide an electrically variable transmission with a continuously variable range of speed ratios and four fixed forward speed ratios between said input member and said output member.

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 continuously connected with at least one member of said gear sets, and said output member being continuously connected with another 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 first gear set with said first member of said third gear set;
• a third interconnecting member continuously connecting said second member of said second gear set with said second member of said third gear set;
• said first motor/generator being continuously connected with a member of said first, second or third gear set;
• said second motor/generator being continuously connected with a member of said first, second or third gear set which is different from said member continuously connected with said first motor/generator;
• a first torque transfer device selectively connecting a member of said first or third gear set with another member of said second or third gear set;
• a second torque transfer device selectively connecting a member of said first, second or third gear set with another member of said first, second or third gear set, the pair of members connected by said second torque transfer device being different from the pair of members connected by said first torque transfer device;
• a third torque transfer device selectively grounding a member of said first, second or third gear set;
• a fourth torque transfer device is connected in parallel with one of said first and second motor/generators for selectively preventing rotation thereof;
• a fifth torque transfer device, such as a motor brake, connected in parallel with the other one of said first and second motor/generators for selectively braking rotation thereof;
• wherein said first, second, third, fourth and fifth torque transfer devices are engageable alone or in pairs to provide an electrically variable transmission with a continuously variable range of speed ratios and four fixed forward speed ratios.