Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Magnetic Preloading System for Pivot Bearing

IP.com Disclosure Number: IPCOM000119642D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 35K

Publishing Venue

IBM

Related People

Fukushima, Y: AUTHOR [+3]

Abstract

Disclosed is a preloading system for a pivot bearing which is used in an HDD (Hard Disk Drive) which has a rotary actuator mechanism. Radial preloading is made on the pivot bearing by a magnetic attracting force between a permanent magnet and a steel piece, which is mounted nearby moving coil of the rotary actuator.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Magnetic Preloading System for Pivot Bearing

      Disclosed is a preloading system for a pivot bearing
which is used in an HDD (Hard Disk Drive) which has a rotary actuator
mechanism.  Radial preloading is made on the pivot bearing by a
magnetic attracting force between a permanent magnet and a steel
piece, which is mounted nearby moving coil of the rotary actuator.

      A bearing of an actuator pivot in HDD is preloaded for precise
actuator positioning in normal use.  The figure is a cross section
showing one example of HDD using the magnetic preloading system.  An
actuator arm 1 is fixed to a pivot shaft 2 to which an upper bearing
3 and a lower bearing 4 are mounted.  A steel piece 5 on the actuator
arm 1 is attracted toward a permanent magnet 6 by a magnetic force.
Then, the magnetic force is transformed into a moment force around
the pivot.  Next, the moment force generates a radial force to the
lower bearing 4.  The radial force is calculated by the following
equation:
 f=F*l/r
 where F:  magnetic force
       l:  distance between steel piece 5 and pivot center
       f:  radial force to lower bearing 4
       r:  distance between upper bearing 3 and lower bearing 4

      This equation shows that 'f' is controlled by 'F', 'l' and 'r'.
'F' is controlled by the area of the steel piece and by the distance
between the steel pieces and the permanent magnet 6.