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High Precision Quiet Spindle Assembly

IP.com Disclosure Number: IPCOM000099600D
Original Publication Date: 1990-Feb-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Dixon, G: AUTHOR [+3]

Abstract

This article describes a method of assembly of a disk file spindle. By using precision tooling, from a single datum, the bearings are first bonded into the spindle hub by their outer races. After insertion of the spindle shaft the inner races are inwardly loaded and bonded to the shaft, eliminating the need for a preload spring. This has been found to improve acoustic performance because movement due to a preload spring is eliminated. An accurate low-cost spindle assembly can be manufactured in medium to high volume with less the 0.01 mm bearing run-out tolerances, having consistent bearing preloads and low vibration.

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High Precision Quiet Spindle Assembly

       This article describes a method of assembly of a disk
file spindle.  By using precision tooling, from a single datum, the
bearings are first bonded into the spindle hub by their outer races.
After insertion of the spindle shaft the inner races are inwardly
loaded and bonded to the shaft, eliminating the need for a preload
spring.  This has been found to improve acoustic performance because
movement due to a preload spring is eliminated.  An accurate low-cost
spindle assembly can be manufactured in medium to high volume with
less the 0.01 mm bearing run-out tolerances, having consistent
bearing preloads and low vibration.

      The stages in assembly are shown in sequence from Fig. 1 to
Fig. 5.  The assembly is tooled from a common datum D to minimize
tolerance build-ups commencing with the sleeve 1 in Fig. 1.  The
first bearing 2 in Fig. 2 is fitted with tool 1 into position in
sleeve 1 with a light load 3 applied to the top outer race of bearing
2 to ensure correct seating 10 relative to D.  Bearing 2 is retained
in this position by bonding.

      The second bearing 3 in Fig. 3 is similarly positioned with
tool 2 from the same datum D to achieve the required positioning.  To
assist in accurate axial positioning, a friction ring 4 may be used.
Friction ring 4 is a light press fit in sleeve 1 and therefore
enables the bearing 3 to be pushed in with the ring 4 ahead of it
into the required position. If frictio...