Patent ID: 8823227

Claim:
A drive unit comprising: a housing forming a stator; a drive element arranged for rotation within the stator; an output element arranged in the housing; a transmission stage for transferring drive torque via the drive element to the output element, wherein the transmission stage comprises a plurality of movable toothed segments, and the drive element and transmission stage are arranged coaxially and lie in a common plane (E); and the drive element has a contoured inner surface which acts on the plurality of movable toothed segments, wherein the drive element has an outer surface having a plurality of magnetic field exciters arranged on the outer surface, wherein the magnetic field exciters comprise permanent magnets, wherein the transmission stage comprises an element having the plurality of toothed segments inserted into guides, wherein the toothed segments are capable of radial movement and wherein the element is coaxially within the drive element, wherein an intermediate element comprising a segmented bearing ring is provided between the toothed segments and the contoured inner surface, and wherein the contoured surface acts via the intermediate element on the plurality of movable toothed segments.