公开(公告)号：DE69027208D1

公开(公告)日：1996-07-04

申请号：DE69027208

申请日：1990-01-08

Applicant: IBM

Inventor： DEW GRAHAM ,  HEARN ANTHONY ,  SEBBORN DAVID ,  YOUNG JULIAN

IPC: G11B17/038 ,  G11B17/00 ,  G11B19/20 ,  G11B23/03 ,  G11B25/04 ,  G11B33/14

Abstract: PCT No. PCT/GB90/00020 Sec. 371 Date Oct. 1, 1992 Sec. 102(e) Date Oct. 1, 1992 PCT Filed Jan. 8, 1990 PCT Pub. No. WO91/11004 PCT Pub. Date Jul. 25, 1991.A disk file includes an expansion ring attached to the wall of the hub and which is located between the lowermost disk of the disk stack and the hub flange. A circular ridge concentric with the hub is formed on the ring and engages the underside of the disk. The ring is adapted so that the thermal expansion of the ring is substantially equal to that of the aluminum disk at the position of contact between the two. A washer interposed between ring and flange allows the ring to move freely relative to the flange. During thermal cycling, the ring and disk move at the same rate at the point of contact, the ring ensuring that the disks remain concentric with the hub throughout the range of disk file operating temperatures.