Flat coil carrier

A flat coil, comprising a flat coil carrier and a coil wire, the coil carrier including:

• a carrier body including a groove spiral;
• the groove spiral disposed on an axial front side of the carrier body and having an axially open groove opening;
• the groove spiral extending spirally on the carrier body such that a spiral separating wall protruding axially from the carrier body extends parallel to the groove spiral and separates radially adjacent portions of the groove spiral;
• wherein the carrier body further includes a plurality of protrusions projecting radially from the spiral separating wall into the groove spiral such that a plurality of undercuts configured to receive the coil wire are defined;
• wherein, relative to a radial center of the groove spiral, the plurality of protrusions project radially outward from the spiral separating wall;
• wherein the coil wire is received in the groove spiral;
• wherein the plurality of protrusions are arranged along the spiral separating wall longitudinally spaced apart from one another such that the spiral separating wall includes a plurality of longitudinal undercut sections and a plurality of longitudinal separating sections disposed in an alternating manner;
• wherein the carrier body further includes a plurality of undercut segments and a plurality separating segments extending radially from the radial center of the groove spiral and disposed about the radial center in an alternating manner;
• wherein the plurality of undercut segments are each defined by a subset of the plurality of undercut sections that are disposed in radial alignment with one another;
• wherein the plurality of separating segments are each defined by a subset of the plurality of separating sections that are disposed in radial alignment with one another;
• wherein the plurality of undercut segments each extend over an angular area of 60° or less;
• wherein the carrier body further includes a plurality of axial apertures disposed in a bottom of the groove spiral;
• wherein, in at least one of the plurality of longitudinal undercut sections, a radial surface of the spiral separating wall, which faces toward or away from the radial center of the groove spiral, defines at least a portion of a respective undercut of the plurality of undercuts and at least a portion of a respective axial aperture of the plurality of axial apertures;
• and
• wherein, in at least one of the plurality of longitudinal undercut sections, a respective protrusion of the plurality of protrusions and a respective axial aperture of the plurality of axial apertures are at least partially aligned with one another in the axial direction.

A flat coil, comprising a coil wire and a flat coil carrier including a carrier body, wherein:

• the carrier body includes:
• a groove spiral extending spirally around an axis extending in an axial direction, the groove spiral disposed on an axial front side of the carrier body and having an axially open groove opening;
• a spiral separating wall protruding axially from the carrier body, extending parallel to the groove spiral, and separating radially adjacent portions of the groove spiral;
• at least one protrusion projecting radially from the spiral separating wall into the groove spiral such that an undercut configured to receive the coil wire is defined;
• and
• at least one axial aperture disposed in a bottom of the groove spiral, the at least one protrusion and the at least one axial aperture at least partially aligned with one another in the axial direction;
• the coil wire is received in the groove spiral;
• the coil wire has a diameter that is i) larger than a radial dimension of the at least one protrusion and ii) smaller than a radial dimension of a radially reduced portion of the groove opening defined between the at least one protrusion and the spiral separating wall;
• and
• a curved surface is arranged at a transition between the at least one protrusion and the spiral separating wall, the curved surface defining a corner region of the undercut and having a curvature corresponding to an outer contour of the coil wire.