Illumination device for vehicle headlamps, especially for single-track vehicle headlamps, comprising: - an optical unit with at least one light source, said optical unit is configured to form a light distribution with a cut-off line, wherein the light distribution being radiated in a main beam direction and - an adjusting mechanism for rotating the optical unit about a first axis by means of a pivot bearing, wherein the first axis is oriented parallel to the main beam direction, wherein the pivot bearing comprises a first ring and a second ring, arranged concentrically and rotatable to each other about the first axis, wherein the optical unit is attached to the first ring, and wherein the adjusting mechanism comprises - a holder, attached to the second ring, and - a gear wheel element, which is inserted in an opening area of the holder and rotatable about the first axis, said gear wheel element is attached to the first ring of the pivot bearing, characterized in that the adjustment mechanism further comprises - a linear drive with a toothed rack, said linear drive is attached to the holder and configured to generate a linear motion of the toothed rack along a second axis, wherein the toothed rack is configured to engage with the gear wheel element in order to convert a linear motion of the toothed rack into an angular motion of the gear wheel element and the optical unit about the first axis, and wherein the optical unit comprises at least one light-forming component configured to form the light distribution of the optical unit by forming light emitted by the at least one light source, and wherein the optical unit is arranged on a mount, said mount is attached to the first ring of the pivot bearing, wherein the optical unit comprises at least one heatsink configured to dissipate the heat of the at least one light source, wherein the at least one light source is arranged on the at least one heatsink, and wherein the mount is the heatsink configured to dissipate the heat of the at least one light source. - an optical unit with at least one light source, said optical unit is configured to form a light distribution with a cut-off line, wherein the light distribution being radiated in a main beam direction and - an adjusting mechanism for rotating the optical unit about a first axis by means of a pivot bearing, wherein the first axis is oriented parallel to the main beam direction, wherein the pivot bearing comprises a first ring and a second ring, arranged concentrically and rotatable to each other about the first axis, wherein the optical unit is attached to the first ring, and wherein the adjusting mechanism comprises - a holder, attached to the second ring, and - a gear wheel element, which is inserted in an opening area of the holder and rotatable about the first axis, said gear wheel element is attached to the first ring of the pivot bearing, - a holder, attached to the second ring, and - a gear wheel element, which is inserted in an opening area of the holder and rotatable about the first axis, said gear wheel element is attached to the first ring of the pivot bearing, characterized in that the adjustment mechanism further comprises - a linear drive with a toothed rack, said linear drive is attached to the holder and configured to generate a linear motion of the toothed rack along a second axis, - a linear drive with a toothed rack, said linear drive is attached to the holder and configured to generate a linear motion of the toothed rack along a second axis, wherein the toothed rack is configured to engage with the gear wheel element in order to convert a linear motion of the toothed rack into an angular motion of the gear wheel element and the optical unit about the first axis, and wherein the optical unit comprises at least one light-forming component configured to form the light distribution of the optical unit by forming light emitted by the at least one light source, and wherein the optical unit is arranged on a mount, said mount is attached to the first ring of the pivot bearing, wherein the optical unit comprises at least one heatsink configured to dissipate the heat of the at least one light source, wherein the at least one light source is arranged on the at least one heatsink, and wherein the mount is the heatsink configured to dissipate the heat of the at least one light source.