公开(公告)号：JPH11339411A

公开(公告)日：1999-12-10

申请号：JP12082499

申请日：1999-04-28

Applicant: IBM

Inventor： THOMAS R ALBRECHT ,  CHARLES H HEINO JR ,  TSUAI WEI WOO

IPC: G11B21/12 ,  G11B5/54 ,  G11B5/55 ,  G11B21/22

Abstract: PROBLEM TO BE SOLVED: To make avoidable the position deviation due to the thermal expansion to easily and accurately mount by comprising a load-unload ramp defining the ramp-disc spacing from a data memory disc and selecting the thermal expansion coefficient of a rigid support structure to be mounted so that the ramp-disc spacing is const. during temp. change. SOLUTION: The material of a rigid support structure 52 is selected to have a thermal expansion rigorously agreeing with that of a spindle 26, and the spindle 26, spacer ring 29, disc 30 and rigid support structure 52 are pref. made of the same material. A ramp unit 50 moves due to the expansion/shrinkage of the rigid support structure 52 and has a small vertical range 55 and hence the thermal expansion movement of the rigid support structure 52 dominates over that of the ramp 32. The spindle 26 and the rigid support structure 52 expand/shrink at the same proportion and hence the spacing 38 between the ramp and disc is const. in a disc plane-ramp pair.