Wrap-around driveline with multi-speed transmission

A driveline for transferring torque from an engine output member of an engine to front wheels of a vehicle comprising:

• a transmission having:
• a transmission casing having a first end wall, a second end wall, and a housing portion interconnecting the first end wall and the second end wall;
• wherein the end walls and the housing portion define a cavity;
• a transmission input member;
• a transmission output member;
• wherein the transmission input member and the transmission output member are aligned with one another and with the front wheels to thereby define a transmission axis about which the transmission input member and the transmission output member rotate;
• wherein the transmission axis is parallel with and spaced from an engine axis defined by the engine output member and about which the engine output member rotates;
• first, second, third and fourth planetary gear sets within the cavity, each planetary gear set having a ring gear member, a sun gear member, and a carrier member rotatably supporting pinion gears intermeshing with both the ring gear member and the sun gear member;
• wherein the transmission casing and the first, second, third and fourth planetary gear sets define six zones within the cavity, including a first zone extending axially from the first end wall to the first planetary gear set and extending radially to an outer periphery of the first, second, third and fourth planetary gear sets, a second zone extending axially from the first planetary gear set to the second planetary gear set and extending radially to the outer periphery of the first, second, third and fourth planetary gear sets, a third zone extending axially from the second planetary gear set to the third planetary gear set and extending radially to the outer periphery of the first, second, third and fourth planetary gear sets, a fourth zone extending axially from the third planetary gear set to the fourth planetary gear set and extending radially to the outer periphery of the first, second, third and fourth planetary gear sets, a fifth zone extending axially from the fourth planetary gear set to the second end wall and extending radially to the outer periphery of the first, second, third and fourth planetary gear sets, and a sixth zone bordering the first, second, third, fourth and fifth zones and extending radially outward to the housing portion and axially between the first and second walls;
• wherein the ring gear member of the first planetary gear set is continuously connected for common rotation with the sun gear member of the second planetary gear set;
• wherein the ring gear member of the second planetary gear set is continuously connected for common rotation with the carrier member of the third planetary gear set;
• wherein the ring gear member of the third planetary gear set is continuously connected for common rotation with the carrier member of the fourth planetary gear set;
• wherein the sun gear member of the third planetary gear set is continuously connected for common rotation with the sun gear member of the fourth planetary gear set;
• wherein the sun gear member of the first planetary gear set is grounded to the transmission casing;
• five torque-transmitting mechanisms for selectively interconnecting the members of the planetary gear sets with the stationary members or with other members of the planetary gear sets;
• wherein the torque-transmitting mechanisms are selectively engagable in different combinations to achieve eight forward speed ratios and a reverse speed ratio between the transmission input member and the transmission output member;
• and
• at least one rotatable element operable to transfer torque from the engine output member to the transmission input member;
• and
• an additional planetary gear set having a ring gear member, a sun gear member and a carrier member, one of the members of the additional planetary gear set being connected for common rotation with the transmission output member and each of the members of the additional planetary gear set being concentric about the transmission axis;
• a differential mechanism having a first, a second and a third member;
• wherein the first member of the differential mechanism is connected for common rotation with one of the members of the additional planetary gear set that is not connected for common rotation with the transmission output member;
• wherein the second member of the differential mechanism is connected for common rotation with a first of the front wheels;
• a drive shaft running coaxial with the transmission axis through the first, second, third and fourth planetary gear sets;
• and wherein the third member of the differential mechanism is connected for common rotation with a second of the front wheels via the drive shaft.