Multi-mode electromechanical variable transmission

A drive system for a vehicle, comprising:

• a first planetary gear set;
• a second planetary gear set directly coupled to the first planetary gear set;
• an engine directly coupled to the first planetary gear set with a connecting shaft, wherein the first planetary gear set, the second planetary gear set, and the connecting shaft are radially aligned;
• a first electromagnetic device coupled to the first planetary gear set, wherein the first electromagnetic device includes a first shaft;
• a second electromagnetic device directly coupled to the second planetary gear set and selectively rotationally engaged with the engine, wherein the second electromagnetic device includes a second shaft, wherein the first shaft and the second shaft are radially aligned with the first planetary gear set, the second pplanetary gear set, and the connecting shaft, and wherein the connecting shaft extends through the second electromagnetic device and through the second planetary gear set to the first planetary gear set;
• and
• an output selectively coupled to the first planetary gear set and the second planetary gear set, wherein the output is radially offset from the first planetary gear set, the second planetary gear set, and the connecting shaft.

A vehicle, comprising:

• a multi-mode transmission including:
• a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier, wherein the first planetary gear carrier and the second planetary gear carrier are rotatably coupled;
• a first motor/generator coupled to the first gear set;
• and
• a second motor/generator coupled to the second gear set;
• an engine selectively coupled to the second gear set;
• and
• a drive axle selectively coupled to the multi-mode transmission;
• wherein during a power generation mode of the multi-mode transmission the engine is coupled to the second motor/generator and isolated from the drive axle, and
• wherein during a series electric mode of the multi-mode transmission the engine is decoupled from the second motor/generator, the second motor/generator is selectively coupled to the drive axle, and the engine is coupled to the first motor/generator such that rotation of the first motor/generator by the engine generates electricity to power the second motor/generator.