Dental drill bearings

The utility model discloses a bur bearing and relates to the field of medical oral cavity appliance. The bur bearing comprises a bearing inner ring, a bearing outer ring and a rolling ball positioned between the bearing inner ring and the bearing outer ring. The bur bearing is characterized in that the surface of the bearing outer ring is provided with an annular groove; and the annular groove is internally provided with a thrust ring with a gap. As the annular groove of the surface of the bearing outer ring is internally provided with the thrust ring with the gap, the axial displacement of a rubber ring is completely avoided; and the high-speed stable operation of a wind wheel is ensured.