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Motor Magnetizing Fixture

IP.com Disclosure Number: IPCOM000081934D
Original Publication Date: 1974-Sep-01
Included in the Prior Art Database: 2005-Feb-28
Document File: 2 page(s) / 67K

Publishing Venue

IBM

Related People

Hu, PY: AUTHOR

Abstract

This magnetizing fixture is for use with an assembled direct-current motor and may be left in place or it may be removed without changing the motor's torque or voltage constant as a result of such removal.

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Motor Magnetizing Fixture

This magnetizing fixture is for use with an assembled direct-current motor and may be left in place or it may be removed without changing the motor's torque or voltage constant as a result of such removal.

The motor comprises an armature or rotor 10 which rotates about axis 11. This armature is DC energized by stationary brushes and an armature commutator, not shown.

The motor's stator consists of six equally spaced permanent magnets, four of which are shown at 12. These magnets are magnetized to present opposing poles, as shown. A magnetic pole piece 13 is mounted intermediate each of the opposing magnetic poles. As a result, the assembled motor's magnetic flux path consists of a number of closed-magnetic loops, one of which is shown by the exemplary closed-loop arrow 14. The stator is mechanically held together by nonmagnetic rings 15 and bolts 16.

In order to accurately adjust the motor's torque and/or voltage constants to a given value, +1%, an external magnetizing fixture is placed in a position surrounding the motor.

This fixture consists of an outer nonmagnetic shell 17, preferably aluminum, which mounts six magnetic pole pieces 18 about the inner diameter thereof. Each of these pole pieces is encircled by a coil 19. These coils are DC energized so as to produce magnetic poles of alternating polarity at their inner pole surfaces 20. If, for example, it is necessary to reduce the motor's magnetic field 14, the magnetic polarity of pole surfaces 20 will be as indicated. T...