Patent ID: 6361737
Filing Date: 2002-03-26
Classification: B22F,F16C,Y10T

Abstract:
A method for producing a sintered porous bearing, comprising the steps of:placing a cylindrical sintered material in a cavity composed of a hole of a die, a core having a smaller diameter than an internal diameter of the sintered material and disposed in the center of the die, and punches provided within the die, in such a manner that a gap is provided between the internal circumferential portion of the sintered material and an external circumferential portion of the core, and that an external circumferential portion of the sintered material circumferentially contacts with an internal circumferential portion of the hole of the die; approaching the punches to each other in an axial direction of the sintered material until each end face of the punches contacts each end face of the sintered material in a direction perpendicular to the axial direction of the sintered material; and compressing the sintered material by the punches in the axial direction so that both end portions of the internal circumferential portion of the sintered material near to the end faces of the sintered material protrude inward in a radius direction in the gap, until both end portions of the internal circumferential portion of the sintered material near to the end faces of the sintered material come into contact with the external circumferential portion of the core to form side portions sliding on a shaft to be inserted into the sintered porous bearing; wherein the external circumferential portion of the sintered material circumferentially is kept with the original external circumferential configuration without any deformation of the external circumferential configuration during the compressing step.