Full-time all-wheel drive power take-off unit for motor vehicle

A motor vehicle comprising:

• a powertrain including an engine and a transmission;
• a pair of front wheels interconnected to a pair of front axleshafts;
• a rear driveline including a rear differential having an input connected to a first end of a propshaft, and first and second outputs connected to a pair of rear wheels;
• a power transfer unit having an input shaft driven by said powertrain, an interaxle differential having an input component driven by said input shaft and first and second output components, a front drive assembly including a reduction gearset and a differential gearset, said reduction gearset including a sun gear driven by said first output component of said interaxle differential, a fixed ring gear, a carrier driven at a reduced speed, and planet gears supported by said carrier and meshed with said sun gear and said ring gear, said differential gearset includes a ring gear driven by said carrier of said reduction gearset, a pinion carrier driving one of said front axleshafts, a sun gear driving the other of said front axleshafts, and pinions supported from said pinion carrier that mesh with at least one of said sun gear and said ring gear, a rear drive assembly including an input driven by said second output component of said interaxle differential, an output operably connected to a second end of said propshaft, and a right-angled gearset interconnecting said input to said output, a biasing clutch operably disposed between two components of said interaxle differential, a clutch actuator for engaging said biasing clutch, and a traction control system for controlling actuation of said clutch actuator.

A power transfer unit for a four-wheel drive vehicle having a powertrain and front and rear drivelines, comprising:

• an input shaft adapted to be driven by the powertrain;
• an interaxle differential having a first sun gear as a first output, a second sun gear as a second output, a first carrier as an input that is driven by said input shaft, a set of first planet gears rotatably supported by said first carrier and meshed with said first sun gear, and a set of second planet gears rotatably supported by said first carrier and meshed with said second sun gear and said first planet gears;
• a final drive unit having a third sun gear driven by said first sun gear, a first ring gear fixed to a stationary member, and a set of first pinion gears meshed with said first ring gear and said third sun gear and which are rotatably supported from a second carrier;
• a differential unit having a second ring gear driven by said second carrier, a fourth sun gear fixed to one of a pair of front axleshafts associated with the front driveline, a third carrier fixed to the other of said pair of front axleshafts, a set of second pinion gears rotatably supported from said third carrier and meshed with said second ring gear, and a set of third pinion gears rotatably supported from said third carrier and meshed with said fourth sun gear and said second pinion gears;
• a rear drive assembly having an input driven by said second sun gear, an output adapted for connection to the rear driveline, and a right-angled gearset interconnecting said input to said output;
• a biasing clutch operably disposed between said input and one of said first and second outputs of said interaxle differential;
• a clutch actuator for engaging said biasing clutch;
• and
• a traction control system for controlling actuation of said clutch actuator.

A power transfer unit for a four-wheel drive vehicle having a powertrain and sets of first and second wheels, comprising:

• an input shaft adapted to be driven by the powertrain;
• a first planetary gearset having an input driven by said input shaft, and first and second outputs, wherein said input of said first planetary gearset is a first carrier, said first output is a first sun gear, and said second output is a second sun gear;
• a second planetary gearset having an input driven by said first output of said first planetary gearset and an output driven at a reduced speed;
• a third planetary gearset having an input driven by said output of said second planetary gearset, a first output driving a first axleshaft and a second output driving a second axleshaft, said first and second axleshafts driving the set of first wheels;
• and
• a transfer assembly having an input driven by said second output of said first planetary gearset, an output operably connected to the pair of second wheels, and a transfer unit for transmitting rotary power from said input to said output.

A power transfer unit, comprising:

• an input shaft;
• an interaxle differential having an input carrier driven by said input shaft, a first output sun gear, a second output sun gear, and gear means for transferring drive power from said input carrier to said first and second output sun gears;
• a final drive assembly having an input sun gear driven by said first output sun gear, a fixed ring gear, an output carrier, and pinion gears supported on said output carrier and meshed with said fixed ring gear and said input sun gear;
• a differential unit having an input driven by said output carrier, a first output driving a first axleshaft, a second output driving a second axleshaft, and second gear means for transferring drive power from said input to said first and second outputs;
• a bevel gearset;
• and
• transfer means for transferring drive power from said second output sun gear to said bevel gearset.