초록 ▼

A drive system for a four-wheel drive motor vehicle, in particular an agricultural tractor, includes a gradually lockable differential for the front wheels, a gradually lockable differential for the rear wheels, and a gradually lockable center differential in the drive to the front and rear differen

A drive system for a four-wheel drive motor vehicle, in particular an agricultural tractor, includes a gradually lockable differential for the front wheels, a gradually lockable differential for the rear wheels, and a gradually lockable center differential in the drive to the front and rear differential gears. The degree of locking of the respective differentials is controlled by a control circuit based upon their relative rotational speeds, the steering angle and the temperature in the center differential. In an alternative embodiment, brakes on each wheel and on the shafts connecting the center differential to the front and rear differential are used to supplement or replace the differential locks.

대표청구항 ▼

A drive system for a motor vehicle, comprising: a front pair and a rear pair of wheels, at least one pair of which can be steered; a front differential and a rear differential, each drivably connected to a respective one of said front and rear wheel pairs; a center differential drivably connected to

A drive system for a motor vehicle, comprising: a front pair and a rear pair of wheels, at least one pair of which can be steered; a front differential and a rear differential, each drivably connected to a respective one of said front and rear wheel pairs; a center differential drivably connected to said front and rear differentials; adjustment means comprising a gradually engageable lock for each said differential for adjusting the speeds of any relative rotation within each of said differentials; a sensor for determining a steering angle of said steerable pair of wheels; a plurality of wheel speed sensors, each determining a rotational speed of a corresponding one of said wheels; a plurality of differential speed sensors, each determining a rotational speed of a corresponding one of said front and rear differentials; and a control circuit including means for controlling said adjustment means based upon the sensed steering angle and rotational speeds, said control circuit comprising: means for calculating the ratio of the sensed rotational speeds of said front wheels; means for comparing said calculated ratio to a reference value corresponding to the sensed steering angle; and means for decreasing the degree of locking of said front differential by a first predetermined amount if said calculated ratio corresponds to said reference value, and for increasing the degree of locking of said front differential by a second predetermined amount if said calculated ratio does not correspond to said reference value.