A sintered bearing includes, on an inner peripheral surface, a cylindrical portion and a one-side increased-diameter portion, which are provided so as to be continuous in the axial direction. An end portion of one side in the axial direction of the cylindrical portion and an end portion of another side in the axial direction of the increased-diameter portion coincide, and the cylindrical portion and the increased-diameter portion are molded by performing sizing on a sintered compact having a tubular shape, which is introduced into a die.

Provided is a method of manufacturing a sintered bearing including, on an inner peripheral surface, a cylindrical portion and a one-side increased-diameter portion (increased-diameter portion), which are provided so as to be continuous in the axial direction. When sizing is performed on a sintered compact, the cylindrical portion and the one-side increased-diameter portion are molded on an inner peripheral surface of the sintered compact by press-fitting a cylindrical portion molding surface formed on a core into an inner peripheral surface of the sintered compact from the one side in the axial direction, and then by pressing a one-side increased-diameter portion molding surface provided so as to be continuous with the cylindrical portion molding surface in the axial direction against an inner peripheral surface of the sintered compact under a state in which an outer peripheral surface of the sintered compact is retained by a die.

A sintered bearing includes a cylindrical portion, one-side increased-diameter portion and another-side increased-diameter portion. A metal structure of the another-side increased-diameter portion has a higher density than a metal structure of a core portion of the sintered compact. A metal structure of the cylindrical portion has an expansion along a direction of ironing by the sizing core and a higher density than the metal structure of the another-side increased-diameter portion. A metal structure of the one-side increased-diameter portion has an expansion along a direction of ironing by the sizing core and a higher density than the metal structure of the cylindrical portion.

Provided is a method of manufacturing a sintered bearing including, on an inner peripheral surface, a cylindrical portion and a one-side increased-diameter portion (increased-diameter portion), which are provided so as to be continuous in the axial direction. When sizing is performed on a sintered compact, the cylindrical portion and the one-side increased-diameter portion are molded on an inner peripheral surface of the sintered compact by press-fitting a cylindrical portion molding surface formed on a core into an inner peripheral surface of the sintered compact from the one side in the axial direction, and then by pressing a one-side increased-diameter portion molding surface provided so as to be continuous with the cylindrical portion molding surface in the axial direction against an inner peripheral surface of the sintered compact under a state in which an outer peripheral surface of the sintered compact is retained by a die.