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公开(公告)号:JPH08124287A
公开(公告)日:1996-05-17
申请号:JP26513094
申请日:1994-10-28
Applicant: IBM
Inventor: SATO KIYOSHI , SASAKI MASAKAZU , KITABORI HIRONORI , NEMOTO SUNAO , DEEBITSUDO ARUBUREHITO , GUREGORII FURIIZU
Abstract: PURPOSE: To equalize the coupled resonance frequency of a hard disc drive at the time of loading one magnetic disc and two magnetic discs based on the parameters of a model. CONSTITUTION: Assuming the spring coefficient of a spindle motor is Kp and the mass thereof is Mp, while the spring coefficient of a magnetic disc is Kd and the mass thereof is Md, a disc drive is modeled by a coupled vibration model (A) of a linear two degree of a freedom system for a case (B) loaded with a single disc and a case (C) loaded with two discs. The spring coefficient Kp of the spindle motor, i.e., the components, are then adjusted such that the coupled resonance frequency of the spindle motor and the disc is substantially constant for the case loaded with a single disc and the case loaded with two discs. According to the arrangement, stabilized track follow can be ensured without requiring any additional disc.
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公开(公告)号:JPH09282787A
公开(公告)日:1997-10-31
申请号:JP7485496
申请日:1996-03-28
Applicant: IBM
Inventor: SATO KIYOSHI , DEBITSUDO ARUBUREHITO , NEMOTO SUNAO
IPC: G11B19/20 , G11B17/022 , G11B33/08 , G11B33/14
Abstract: PROBLEM TO BE SOLVED: To reduce the deformation of a hub by providing a reduced stress region having an inner peripheral diameter of the hub in a part of a joined region larger than in other parts and reducing stress between the outer periphery of a sleeve and the inner periphery of the hub when a thermal expansion occurs because of a temperature change. SOLUTION: Because of a change in temperature, stress of vector A or B is produced in the full inner periphery of a hub, thus an imbalance occurs in a joined part between a hub 14 and a sleeve 11, distortion occurs in the hub and a thermal runout, that is, rotational shaking occurs in a disk loaded in the hub. The inner peripheral diameter of the center part of a joined region between the hub 14 and the sleeve 11 is larger than that of each of the upper and lower joined parts 24 and 25 of the joined region, thus a stress reducing region 23 is formed. In a left part V, a difference between the stress vectors A' and B' of the upper and lower ends of the reducing region is smaller than that between the vectors A and B. This is because no stress occurs between the hub 14 and the sleeve 11 caused by a linear expansion coefft. difference. By reducing the imbalance between the stress vectors, thermal runout is reduced.
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