Keith K Kessler

US Patent:

49221590, May 1, 1990

Filed:

May 9, 1988

Appl. No.:

7/191368

Inventors:

Douglas J. Phillips - Melbourne FL
Keith E. Kessler - Palm Bay FL
John W. Shipley - Palm Bay FL
Dave Hyland - Melbourne Beach FL

Assignee:

Harris Corporation - Melbourne FL

International Classification:

H02K 524
F16K 3108

US Classification:

318128

Abstract:

A high precision linear actuator for compensating short stroke, high frequency vibrations in a space deployed structure comprises a set of cylindrical magnetic pole pieces affixed to respective ones of a pair of graphite flexures, that are mounted to a thermally conductive cylindrical housing, which is to be affixed to the space deployed structure. Reaction against the "proof mass" pole pieces is achieved by a magnetic field produced by set of stationary magnetic coils that surround the pole pieces and are energized by a vibration compensation reaction current supplied from a sense/control processor. Coaxial with and mounted integrally with the cylindrical pole pieces of the proof mass is an internal accelerater, which generates an output signal representative of the force to which the proof mass is subjected. This output signal is monitored by the sense/control processor to close a force feedback loop and effectively reduce both the inherent resonance imparted by the spiral support flexures and non-linearities in the magnetic field, against which the "proof mass" cylindrical pole pieces react in the course of operation of the actuator. The vibration compensation drive signal that is supplied by the sense/control processor may be based upon the output of a second accelerometer that is mounted integrally with the cylindrical housing, but external to the flexures, by way of which the "proof mass" pole pieces, associated drive coils and internal accelerometer are supported.