Browse Prior Art Database

Capstan Motor having Integral Analog and Digital Tachometers

IP.com Disclosure Number: IPCOM000081933D
Original Publication Date: 1974-Sep-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Hu, PY: AUTHOR [+2]

Abstract

This high torque - low inertia capstan motor/tachometer assembly is n constructed to insure that the assembly exhibits a high mechanical resonant frequency characteristic with a single-mode resonance.

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Capstan Motor having Integral Analog and Digital Tachometers

This high torque - low inertia capstan motor/tachometer assembly is n constructed to insure that the assembly exhibits a high mechanical resonant frequency characteristic with a single-mode resonance.

Tape drive capstan 10 is mounted on shaft 11 and carries the see-thru disc 12 of a digital tachometer. This disc cooperates with the optical tachometer's stationary portion 13. This digital tachometer's pulse output signal is a direct function of the capstan's angular displacement and speed.

The shaft rotates in bearings 15 and 16. These bearings are mounted in nonmagnetic end bells 17 and 18. Magnets 19 and 20 are cantilever supported by end bells 17 and 18, respectively. The shaft 11 freely passes through aligned bores in the magnets and supports a nonmagnetic hub 22 which rotates with the shaft.

Annular flux return tube assembly 21 cooperates with magnets 19 and 20, respectively, to define two tubular air gaps therebetween. The magnets present an even number of magnetic poles, of alternating magnetic polarity, about the inner circumference of each of the air gaps.

A hollow motor armature 23 is mounted on electrical insulating hub 22 in the air gap between magnet 19 and flux return tube 21. Armature 23 carries a DC winding thereon, for example, a lap or a wave winding. This winding is DC energized by way of brushes 24 so as to cause capstan 10 to be driven by shaft
11.

A hollow analog tachometer armature...