Electric drive unit and powertrain system incorporating the same

A powertrain system comprising:

• a first driveline having a first pair of wheels;
• a second driveline having a second pair of wheels;
• a primary propulsion system that acts to generate and translate a first rotational torque only to said first pair of wheels of said first driveline;
• an auxiliary propulsion system that acts to generate and translate a second rotational torque only to said second pair of wheels of said second driveline, said auxiliary propulsion system including an electric drive unit having:
• an electric motor that acts to selectively generate a third rotational torque;
• a pinion disposed in selective rotational communication with said electric motor;
• a differential interposed in torque translating relationship between said pinion and said second pair of wheels for splitting a fourth rotational torque between said pinion and said second pair of wheels;
• a first planetary gearset disposed in selective torque translating relationship between said electric motor and said pinion;
• a second planetary gearset disposed in selective torque translating relationship between said first planetary gearset and said pinion;
• and
• a dog clutch assembly interposed in torque translating relationship between said pinion and said first planetary gearset and said second planetary gearset, wherein said dog clutch assembly is movable between a first position wherein the third rotational torque from said electric motor is translated through said first planetary gearset and said dog clutch assembly to said pinion so as to drive said second pair of wheels at a first predetermined drive ratio, and a second position wherein the third rotational torque from said electric motor is translated through both of said planetary gearsets and said dog clutch assembly to said pinion so as to drive said second pair of wheels at a second predetermined drive ratio.