Patent ID: 8057101

Claim:
An oil-impregnated sintered bearing, comprising: a cylindrical bearing body which is made of a porous sintered alloy containing vacancies and having a bearing hole into which a rotary shaft may be inserted, wherein the bearing body has an outer peripheral surface and an inner peripheral surface, the outer peripheral surface is divided into a semicircular first half area and a semicircular second half area in a circumferential direction of the outer peripheral surface, the inner peripheral surface is divided into a semicircular first half area and a semicircular second half area in a circumferential direction of the inner peripheral surface, the first half area of the outer peripheral surface and the first half area of the inner peripheral surface are on the same side of the cylindrical bearing body, the second half area of the outer peripheral surface and the second half area of the inner peripheral surface are on the same side of the cylindrical bearing body, the vacancies on the first half area of the outer peripheral surface and the first half area of the inner peripheral surface have a crushed shape, a surface vacancy rate per unit area of the first half area of the outer peripheral surface and the first half area of the inner peripheral surface is 10% or less, the vacancies on the second half area of the outer peripheral surface and the second half area of the inner peripheral surface are not crushed, and a surface vacancy rate per unit area of the second half area of the outer peripheral surface and the second half area of the inner peripheral surface is higher than that of the first half area of the outer peripheral surface and the first half area of the inner peripheral surface.