Disk file having thermal expansion ring for ensuring disk/hub concentricity

A disk file including a disk assembly comprising:

• a hub, rotatable about a central axis, having a wall and a peripheral flange;
• at least one data storage disk supported by the flange, the disk and flange being made from materials having dissimilar coefficients of thermal expansion;
• clamping means for clamping said disk to said flange;
• and
• compensation means located between a surface of the flange and an opposed surface of the disk, for ensuring that the disk remains concentric with the hub during temperature changes, said compensation means including:
• an annular ring having a coefficient of thermal expansion different to that of the hub, said ring comprising a substantially flat annular outer portion concentric with the hub, a raised portion projecting from the substantially flat annular outer portion, said raised portion being concentric with the hub and in non-slipping contact with the surface of the disk, and a resilient weakened section located radially inward of the raised portion and coplanar with the outer portion, said resilient weakened section being in contact with the hub wall.

A disk file including a disk assembly comprising:

• a hub, rotatable about a central axis, having a wall and a peripheral flange;
• at least one data storage disk supported by the flange, the disk and flange being made from materials having dissimilar coefficients of thermal expansion;
• clamping means for clamping said disk to said flange;
• and
• compensation means located between a surface of the flange and an opposed surface of the disk, for ensuring that the disk remains concentric with the hub during temperature changes, said compensation means including:
• expansion means having a coefficient of thermal expansion different to that of the hub and different to that of the disk, the expansion means being attached to the hub wall and having raised portions concentric with the hub and in non-slipping contact with the surface of the disk, wherein the coefficient of thermal expansion of the disk is intermediate the coefficient of thermal expansion of the hub and the coefficient of thermal expansion of the expansion means.