Browse Prior Art Database

Combined Air and Magnetic Bearing System

IP.com Disclosure Number: IPCOM000105696D
Original Publication Date: 1993-Sep-01
Included in the Prior Art Database: 2005-Mar-20
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Watrous, RB: AUTHOR

Abstract

Data storage files typically have actuators with ball-bearing-supported carriages. The detrimental friction and wear of these bearings can be eliminated by replacing them with air bearings. A cylindrical bearing is the least expensive form. Its stator can be a precision ground metal or ceramic rod, and the moving cylindrical sleeve, which is supported by the air film, can be a vacuum formed, precision inside diameter, glass tube. A magnetic bearing can be employed to restrain the cylindrical bearing from rotating about its longitudinal axis.

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Combined Air and Magnetic Bearing System

      Data storage files typically have actuators with
ball-bearing-supported carriages.  The detrimental friction and wear
of these bearings can be eliminated by replacing them with air
bearings.  A cylindrical bearing is the least expensive form.  Its
stator can be a precision ground metal or ceramic rod, and the moving
cylindrical sleeve, which is supported by the air film, can be a
vacuum formed, precision inside diameter, glass tube.  A magnetic
bearing can be employed to restrain the cylindrical bearing from
rotating about its longitudinal axis.

      An arrangement embodying these ideas is shown in the figure,
which is a section through a voice coil motor (VCM)-type actuator.
The movement of the frame/coils/ sleeve assembly is perpendicular to
the plain of the paper.  Also attached to the frame is a small
anti-rotation magnet located in a gap between two of the eight
stationary VCM magnets.  By having the magnet polarity as shown, the
anti-rotation magnet remains in the middle of the gap as the actuator
strokes back and forth.  The anti-rotation magnet is much shorter, in
the accessing direction, than the VCM magnets.