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Limited Rotation Motor

IP.com Disclosure Number: IPCOM000080434D
Original Publication Date: 1973-Dec-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 2 page(s) / 52K

Publishing Venue

IBM

Related People

Hu, PY: AUTHOR

Abstract

A limited rotation direct-current motor is made from a conventional high torque - low inertia rotary motor, by removing the motor's brushes and attaching flexible conductor strips from the fixed position power terminals to permanent taps on the movable armature winding. This procedure can be applied to flat "pancake" armatures, to tubular printed-circuit armatures, and to cup or basket shaped moving coil armatures having a shaft-mounted commutator.

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Limited Rotation Motor

A limited rotation direct-current motor is made from a conventional high torque - low inertia rotary motor, by removing the motor's brushes and attaching flexible conductor strips from the fixed position power terminals to permanent taps on the movable armature winding. This procedure can be applied to flat "pancake" armatures, to tubular printed-circuit armatures, and to cup or basket shaped moving coil armatures having a shaft-mounted commutator.

Figs. 1, 2 and 3 show these three armatures, respectively. In each case, the two points of permanent electrical connection to the armature winding (Figs. 1 and 2) and the shaft-mounted commutator (Fig. 3) are separated by a mechanical distance equal to 360 degrees divided by the number of alternating magnetic poles, and occupy the positions that the brushes normally occupy.

Figs. 4 and 5 show two conductive shorting strips 10 and 11 soldered to the underlying armature conductors of a tubular armature, such as shown in Fig. 2. Conductive strip 10 is connected to the positive terminal of a direct current energizing source. Conductive strip 11 is connected to the negative terminal. As a result, the current in conductors 12 flows in one direction, under south magnetic pole 13, and the current in conductors 14 flows in the opposite direction, under north pole 15.

Both of these motors are four-pole motors. In each case, the conductive shorting strips are spaced 90 mechanical degrees. Each magnetic fiel...