A bearing unit includes: a thrust damper extendable in an axial direction of a shaft placed in a gearbox, the movement of which toward one side in the axial direction is regulated; a shaft receiver component held by the thrust damper on the other side of the thrust damper in the axial direction; a metal holder that holds the shaft receiver component in such a manner as to be detachable in the axial direction; and an oilless metal held by the metal holder and placed on the other side of the shaft receiver component, in which the thrust damper, the shaft receiver component, the metal holder, and the oilless metal are integrated all together before being incorporated into the gearbox.