Patent ID: 8311717

Claim:
A method of operating a drive train of a vehicle, the drive train comprising a drive unit, a transmission, and an all-wheel splitter having an automatically operated clutch, the all-wheel splitter being located between the transmission and first and second drive output axles, the method comprising the steps of: directing drive unit torque from the drive unit to the transmission and controlling and converting the drive unit torque from the drive unit to transmission output torque, the transmission output torque being transmitted from the transmission to the clutch; controlling the clutch of the all-wheel splitter to variably divide the transmission output torque into clutch output torque and nominal torque, directing the clutch output torque from the clutch to the first drive output axle and the nominal torque to the second drive output axle, the clutch output torque being the drive unit torque minus the nominal torque; controlling the clutch with a control unit to vary the nominal torque, which is defined by an all-wheel drive strategy, such that the transmission output torque is controllably divided into the clutch output torque and the nominal torque; and dividing the transmission output torque, if defined operating conditions of the drive train are met to prevent thermal overload of the clutch.