Patent ID: 8157689

Claim:
A torque transmission unit for a motor vehicle having a permanently driven primary axle and a secondary axle, comprising: a first connection part and a second connection part which are rotatable relative to one another, with the first connection part being adapted for the connection to a drive unit of the motor vehicle and the second connection part being adapted for the connection to the secondary axle of the motor vehicle—or vice versa; furthermore having a plurality of disks which are subdivided in an alternating arrangement into primary disks and secondary disks; a planetary transmission including at least one first transmission element which is rotationally fixedly connected to the first connection part, a second transmission element which is rotationally fixedly connected to the second connection part and a third transmission element which is rotationally fixedly connected to the primary disks, wherein the secondary disks are rotationally fixedly connected to one of the first connection part, to the second connection part or a stationary housing part; an electric coil for the generation of a magnetic field which acts on a magnetorheological medium, with each of the primary disks and secondary disks being surrounded by the magnetorheological medium on at least two sides that define working spaces so that the electric coil, the magnetorheological medium and the primary disks and the secondary disks form a magnetorheological clutch; and wherein the planetary transmission is configured such that a rotational movement of the second connection part relative to the first connection part effects a speed increasing gear ratio with respect to the primary disks.