Spindle motor, information recording and reproducing apparatus having a spindle motor, and manufacturing method of spindle motor
AssigneeMatsushita Electric Industrial Co., Ltd.
InventorsHiromitsu Noda, Shigeo Obata
Life of this patent
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Abstract
A spindle motor of small size, thin type, high reliability, and high performance suited to an information recording and reproducing apparatus is presented. Specifically, a rotary disk is composed by integrally forming a disk board, and a rotary shaft of spindle motor, and a bearing is composed by forming dynamic pressure generating grooves in the rotary shaft of the rotary disk. As a result, small size and thin structure are realized, surface deflection of the disk during rotation of the spindle motor, and its axial center deflection are substantially decreased, and moreover the recording density is enhanced, the number of constituent parts is curtailed, and the cost is saved.
Claims14
A spindle motor comprising:
- a rotary disk including a disk unit, with a rotary shaft, and an information recording layer above said disk unit, the information recording layer being attached from an underside thereof
- a rotor yoke attached to said rotary disk below said rotary disk;
- a rotary magnet affixed to said rotor yoke;
- a bearing unit, including a fixed side bearing member that includes a bearing sleeve and a thrust supporting plate, wherein a plurality of dynamic pressure generating grooves are formed in a) one of an outer circumference of the rotary shaft or an inner circumference of the bearing sleeve, and b) in one of a bottom of said rotary shaft or an upper surface of the thrust supporting plate;
- and
- thrust attracting means for attracting said rotor yoke and said rotary magnet to a side of the fixed side bearing member.
Dependencies are inferred from the claim text.