US Patent 7613273 Apparatus with a moving system and a stationary system

An apparatus includes a first, stationary system, in particular a stator, and a second system which is provided for moving relative to the first system, in particular an armature, a first and second electrical reference potentials which are assigned to the first system and the second system, respectively, and a coupler for potential coupling of the two reference potentials. The coupler is used for the potential coupling of a ground of the moving system to a ground of the stationary system in order to ensure a reliable data transmission between the systems. In order to achieve a coupling with a maximal service life and requires minimal maintenance, the coupler has a field coupling component for mechanically contactless potential coupling.