| 摘要 |
PURPOSE:To provide an oil-impregnated sintered bearing, whose inner diametral part, excellent in a frictional characteristic, is of hourglass form, and its manufacture. CONSTITUTION:A bearing hole 12 of a bearing body 10 made up of a porous sintered alloy is composed of a sliding surface 13, being formed along the intermediate part in the circumferential direction, and a turning shaft is sliding, and a diametral expanding part 14 being ranged with this sliding surface 13 and expanding the diameter in proportion as heading for the outward, and under this constitution, it is composed of crushing a hole of the sliding surface 13. In addition, this oil retaining bearing is manufactured by way of forming the sliding surface 13 after crushing the hole of the inner circumferential surface when frictional force is made to act on the inner circumferential surface surrounding the central part of a through hole, after the diametral expanding part 14 is formed on the inner circumferential surface of this through hole of a sintered body. Since the hole of the sliding surface 13 is crushed, lubricating oil on the sliding surface is in no case leaked out, whereby a firm oil film with no oil-pressure drop on the sliding surface is formed, so any local contact between the turning shaft 11 and the sliding surface 13 is prevented from occurring, thus a frictional factor in the bearing is made reducible. |
