| 摘要 |
PURPOSE:To prevent the deflection of a shaft caused by a gap by pressing an elastic body into a gap between outer rings of upper and lower ball bearings and upper side and lower side bearing containing parts, pressing the elastic body into between the upper and lower ball bearings and a disk placing shaft, too, and eliminating virtually the respective gaps. CONSTITUTION:In a recessed groove 28 pierced in the outside peripheral part of an outer ring 12A of an upper ball bearing 9A, the outside periphery is projected to the outside from the outside peripheral surface of the outer ring 12A in a free state, and a rubber ring 27 detained to an annular elastic body is outsert-molded. In the same way, a recessed groove is pierced in an outer ring 15A of a lower ball bearing 10A, too, in which the rubber ring 27 is outsert- molded. In this way, gaps between the outer rings 12A, 15A of the upper and lower ball bearings 9A, 10A, and upper side and lower side bearing containing parts 6, 8 are absorbed by a restoring force of the rubber ring 27 which has been deformed at the time of insertion, therefore, the deflection of a shaft in the course of rotation of a rotor 19 is extremely small. |
