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Multipole Closed End Linear Motor

IP.com Disclosure Number: IPCOM000074551D
Original Publication Date: 1971-May-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Lindsley, JC: AUTHOR

Abstract

This linear motor provides a greater flux field across a voice-coil type bobbin resulting in higher forces for the same core size than could be achieved by prior linear motors.

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Multipole Closed End Linear Motor

This linear motor provides a greater flux field across a voice-coil type bobbin resulting in higher forces for the same core size than could be achieved by prior linear motors.

Drawing A shows an exposed side view of a multipole closed end linear motor having three poles. Each magnetic pole is comprised of a pair of permanent magnets 3 and 3'. Each magnetic pole has a pole piece 5 for obtaining the desired curvature of the pole. The magnetic circuit is completed by the housing 1 and center core 2. Pole pieces 4 on the center core 2 are used to define the magnetic gap formed between pole pieces 5 and 4 and between which the voice-coil type bobbin 6 is placed. A bucking coil or shorted turn 7 is provided between adjacent magnetic poles 4 and between magnetic poles 4 and housing 1 to reduce any effect of excessive inductance.

Drawing B is a sectional view along sector lines A-A, which shows the configuration of pole pieces 5 with relation to the voice coil bobbin 6. Drawing C, is a top sectional view of the linear motor and shows the means for attaching to the voice coil bobbin 6.

This multipole closed end linear motor provides a constant force on bobbin 6 regardless of the bobbin's position within the housing 1. Magnetic poles 3 are evenly spaced and are of equal size, the space between the magnetic poles being Y and the width of the poles being X. The bobbin 6 length is 2X + 2Y, where it is desired to have the bobbin acted on by two of the magnetic poles at any given instant of time. The stroke of t...