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Torsional Resonance Damping of Rotary Actuator

IP.com Disclosure Number: IPCOM000050554D
Original Publication Date: 1982-Nov-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Dickie, HG: AUTHOR [+2]

Abstract

In order to alter the frequency response characteristics of the torsional resonances of an electromagnetic rotary actuator, damped couplings are provided to transmit the forces between the moving coil of the actuator and an integral load support table. The couplings are bushes, set into a coil support former, through which the former is bolted to the load support table. Each bush comprises concentric metal sleeves with a trapped layer of elastomer in between.

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Torsional Resonance Damping of Rotary Actuator

In order to alter the frequency response characteristics of the torsional resonances of an electromagnetic rotary actuator, damped couplings are provided to transmit the forces between the moving coil of the actuator and an integral load support table. The couplings are bushes, set into a coil support former, through which the former is bolted to the load support table. Each bush comprises concentric metal sleeves with a trapped layer of elastomer in between.

An actuator employing such couplings is shown in Fig. 1. Briefly, the actuator comprises a moving coil 10 located in an annular air gap between permanent magnets 11 and a shroud 12 of soft magnetic material, providing a return path for flux across the gap. The coil 10 is substantially self-supporting in the gap but is supported at its upper end by a moulded partial former 20. The former 20 is freely located onto a spindle assembly 21 which is mounted in bearings (not shown) for rotation. The spindle assembly includes a flared extension 22 which forms a table for supporting a load. The support table 22 is roughly triangular in shape, and it also has an extension portion 23 which cooperates with limit stops to limit the angular range of movement.

The operation of such an actuator in certain types of closed-loop servo system, can result in a need to lower the torsional resonance frequency of the actuator or to de-tune its resonance so that the frequency response is...