A bearing mechanism includes a shaft, a bearing portion, and a cover closing a bottom end of the bearing portion. The bearing portion and the cover are preferably connected to one another by laser welding. A surface of a welded portion formed by the laser welding includes an inclined surface which is inclined such that the further from a central axis a portion thereof is, the axially higher the portion is. With this unique structure, contamination of lubricant used inside the bearing mechanism by fumes generated due to the laser welding is minimized, and therefore a reliable and durable bearing mechanism is provided.