A rotary unit with a brake device, which, for generating a braking effect, is provided with a hysteresis body, which is radially distanced from a rotational axis, and with a subunit, interacting with the same, with a permanent magnet assembly as well as at least one further magnetic field generating apparatus, - wherein the magnetic field of the further magnetic field generating apparatus can be varied with respect to the magnetic field of the permanent magnet assembly, in order to influence the braking effect, - wherein the subunit with the permanent magnet assembly and the further magnetic field generating apparatus is provided on the same side of the hysteresis body and overlaps the same in the axial direction and the magnetic field of the further magnetic field generating apparatus in the area of the hysteresis body may be activated in the same or in the opposite direction with respect to the magnetic field of the permanent magnet assembly, - wherein the further magnetic field generating apparatus is provided with at least one electrifiable winding, wherein the hysteresis body is provided in the form of a hysteresis ring, - wherein the permanent magnet assembly has a first magnetic ring, which is positioned between the radially inner side of the hysteresis ring and the winding, and a second magnetic ring, which is positioned on the radially inner side of the winding, with one or more pairs composed of a magnetic north pole and south pole, respectively, - wherein between the first magnetic ring and the radial inner side of the hysteresis ring a slit for a frictionless rotation is left clear, - wherein the assembly composed of both magnetic rings (2, 3) and the winding disposed therebetween is enclosed by a metallic capsule which increases the magnetic flow density, and - wherein, in the circumferential direction, the north poles and the south poles are formed by the structure of the capsule. - wherein the magnetic field of the further magnetic field generating apparatus can be varied with respect to the magnetic field of the permanent magnet assembly, in order to influence the braking effect, - wherein the subunit with the permanent magnet assembly and the further magnetic field generating apparatus is provided on the same side of the hysteresis body and overlaps the same in the axial direction and the magnetic field of the further magnetic field generating apparatus in the area of the hysteresis body may be activated in the same or in the opposite direction with respect to the magnetic field of the permanent magnet assembly, - wherein the further magnetic field generating apparatus is provided with at least one electrifiable winding, - wherein the permanent magnet assembly has a first magnetic ring, which is positioned between the radially inner side of the hysteresis ring and the winding, and a second magnetic ring, which is positioned on the radially inner side of the winding, with one or more pairs composed of a magnetic north pole and south pole, respectively, - wherein between the first magnetic ring and the radial inner side of the hysteresis ring a slit for a frictionless rotation is left clear, - wherein the assembly composed of both magnetic rings (2, 3) and the winding disposed therebetween is enclosed by a metallic capsule which increases the magnetic flow density, and - wherein, in the circumferential direction, the north poles and the south poles are formed by the structure of the capsule.