Rotary transformer and electric motor

is rotary transformer and electric motor for inductive energy transfer from a primary coil to a secondary coil, which rotationally fixedly connected to a rotor shaft which is mounted relative to the rotatable primary coil, in which the secondary coil having a coil core and a secondary winding, in particular stator coil, which are received in a receiving part, in particular wherein the receiving part is rotationally fixedly connected to the rotor shaft, wherein a lid part is connected with the receiving part, said secondary winding between the lid part and the receiving part is arranged, wherein the core between the cover part and the receiving part is arranged, wherein the coil core comprises a yoke disc with at least two through the yoke disc connected legs having, in particular wherein the secondary winding is arranged between the limbs, wherein the cover part has axially continuous in the circumferential direction, in particular regularly spaced apart recesses, wherein the radial distance of the area of ​​the respective recess covers the radial distance of the coil core or at least a first leg of the coil core, in particular completely covered, wherein the part of the lid covered axial portion overlaps, in particular overlaps genuine, in particular partially overlaps, with the axial covered by the coil core region, in particular wherein the core projects axially into the respective recess in particular wherein the recesses are each formed as a circular ring section.