Multi-mode transmission for vehicle powertrain system

A torque transmission device for a powertrain system, comprising:

• a variator unit for a continuously variable unit (CVU) arranged in parallel with a fixed-gear-ratio transmission to transfer torque between a transmission input member and a transmission output member;
• the transmission input member selectively rotatably coupled to an input member of the CVU by activating a CVU input clutch;
• the transmission output member rotatably coupled to a CVU output member;
• the fixed-gear-ratio transmission including first and second planetary gear sets arranged to transfer torque between the transmission input member and the transmission output member in fixed-gear-ratio modes by selectively activating a plurality of transmission clutches;
• the first and second planetary gear sets each including a plurality of meshingly engaged gear members including a ring gear, a plurality of planet gears coupled to a carrier and a sun gear, wherein each of the gear members represents a node;
• the transmission input member rotatably coupled to one of the nodes of the first planetary gear set and one of the nodes of the second planetary gear set;
• the transmission output member rotatably coupled to another of the nodes of either the first planetary gear set or the second planetary gear set;
• wherein one of the nodes of the first and second planet gear sets is grounded to a transmission case;
• the torque transmission device transferring torque in a continuously variable mode when the CVU input clutch is activated;
• the torque transmission device transferring torque in a first of the fixed-gear-ratio modes including a fixed overdrive input/output speed ratio when the CVU input clutch is deactivated and a first one of the transmission clutches is activated;
• and
• the torque transmission device transferring torque in a second of the fixed-gear-ratio modes including a fixed underdrive input/output speed ratio when the CVU input clutch is deactivated and a second one of the transmission clutches is activated.

A torque transmission device for a powertrain system, comprising:

• a continuously variable unit (CVU) arranged in parallel with a fixed-gear-ratio transmission to transfer torque between a transmission input member and a transmission output member;
• the transmission input member selectively rotatably coupled to an input member of the CVU by activating a CVU input clutch;
• the transmission output member rotatably coupled to a CVU output member;
• the fixed-gear-ratio transmission including first and second planetary gear sets arranged to transfer torque between the transmission input member and the transmission output member in fixed-gear-ratio modes by selectively activating a plurality of transmission clutches;
• the first and second planetary gear sets each including a plurality of meshingly engaged gear members including a ring gear, a plurality of planet gears coupled to a carrier and a sun gear, wherein each of the gear members represents a node;
• the transmission input member fixedly rotatably coupled to one of the nodes of the second planetary gear set and selectively rotatably coupled to one of the nodes of the first planetary gear set;
• the transmission output member rotatably coupled to another of the nodes of either the first planetary gear set or the second planetary gear set;
• the torque transmission device transferring torque in a continuously variable mode when the CVU input clutch and a single one of the plurality of transmission clutches are activated;
• the torque transmission device transferring torque in a first of the fixed-gear-ratio modes including a fixed underdrive input/output speed ratio when the CVU input clutch is deactivated and a first set of two of the transmission clutches is activated;
• and
• the torque transmission device transferring torque in a second of the fixed-gear-ratio modes including a fixed overdrive input/output speed ratio when the CVU input clutch is deactivated and a second set of two of the transmission clutches is activated.