An apparatus for a pivot assembly that can strongly and reliably fix a sleeve to an outer ring, and in addition, that can also solve the problem of out gas. Ball bearing 2 are mated to both ends of a shaft 1, and to the outer circumference of these ball bearings 2, an inner wall part 31 mates a sleeve disposed between both ball bearings 2, and the sleeve 3 was fixed by laser welding to the outer ring 22 of the bell bearings 2.