An axial roller bearing includes two bearing disks placed in plane-parallel relationship to one another. Each bearing disk has a radial section to form a raceway and an axial collar connected to the radial section, wherein the collar of one bearing disk and the collar of the other bearing disk overlap one another. The axial collars are arranged on an inner or outer peripheral edge of the bearing disks and have breaches to define at least one opening of variable size in dependence on a relative rotation of the bearing disks in circumferential direction. A cage is disposed between the bearing disks for accommodating rolling elements.