D.C. motor and reversing circuit

• US 5,877,573 A
• Filed: 07/22/1997
• Issued: 03/02/1999
• Est. Priority Date: 07/22/1997
• Status: Expired due to Fees

• Current Assignee: Siemens Electric Limited
• Original Assignee: Siemens Electric Limited
• Inventors: Oberheide, G. Clarke
• Primary Examiner(s): Stephan, Steven L.
• Assistant Examiner(s): JONES, JUDSON
• Application Number:
  US08/898,310
• Time in Patent Office: 588 Days
• Field of Search: 310/177, 310/50, 310/180, 310/184, 310/238, 310/239, 318/292
• US Class Current: 310/180
• CPC Class Codes: H02K 23/36 having two or more windings; having two or more commutators; having two or more stators

Abstract

A D.C. motor and an associated switch circuit for selecting between forward and reverse motor rotation about a motor axis. Two armature winding portions are disposed on an armature core, A magnetic flux source on the stator provides magnetic flux across an air gap for interaction with these winding portions. One winding portion, when energized, causes armature rotation in a forward sense; the other winding portion, when energized, causes armature rotation in a reverse sense. The associated switch circuit contains first circuit branch, including a first selectively operable switch, connected via certain brushes and commutator to include the one winding portion, and a second circuit branch, including a second selectively operable switch, connected via certain brushes and commutator to include the other winding portion. Operation of the first switch to closed position energizes the one winding portion to cause forward rotation; operation of the second switch to closed position energizes the other winding portion to cause reverse rotation.

Claims

1. An D.C. motor and an associated switch circuit for selecting between forward and reverse motor rotation about a motor axis comprising:

a D.C. motor comprising a stator and an armature, said armature comprising two armature, winding portions disposed on an armature core, said stator comprising a magnetic flux source providing magnetic flux across an air gap between said stator and armature for interaction with said winding portions;

one of said winding portions comprising forward-rotation causing windings for causing rotation of said armature in a forward sense, the other of said winding portions comprising reverse-rotation-causing windings for causing rotation of said armature in a reverse sense;

commutator means disposed on said armature and connected with said winding portions;

first and second pairs of brushes disposed on said stator and engaging said commutator means for delivering electric current to said winding portions via said commutator means;

said associated switch circuit comprising a first circuit branch connected via said first pair of brushes and said commutator means to include said one winding portion and a second circuit branch connected via said second pair of brushes and said commutator means to include said other winding portion;

said first and second circuit branches each comprising a respective first termination and a respective second termination via which the respective circuit branch can he connected across a D.C. voltage supply, said second terminations being connected in common;

said first circuit branch comprising a first selectively operable switch connected between a first brush of said first pair of brushes and the first termination of said first circuit branch for selectively establishing and disestablishing continuity between said first termination of said first circuit branch and said first brush of said first pair of brushes; and

said second circuit branch comprising a second selectively operable switch connected between a first brush of said second pair of brushes and the first termination of said second circuit branch for selectively establishing and disestablishing continuity between said first termination of said second circuit branch and said first brush of said second pair of brushes.

2. An D.C. motor and an associated switch circuit as set forth in claim 1 in which said commutator means comprises two independent commutators, one engaged by said first pair of brushes, and the other engaged by said second pair of brushes.

3. A D.C. motor and an associated switch circuit as set forth in claim 2 in which said first and second brushes of said first pair of brushes are disposed diametrically opposite each other about the motor axis, and said first and second brushes of said second pair of brushes are disposed diametrically opposite each other about the motor axis.

4. A D.C. motor and an associated switch circuit as set forth in claim 1 in which said second terminations have a common connection internal of the D.C. motor.

5. A D. C. motor and an associated switch circuit as set forth in claim 1 in which said winding portions are disposed on a common ferromagnetic portion of said armature core.

6. A D.C. motor and an associated switch circuit as set forth in claim 5 in which said magnetic flux source comprises a permanent magnet providing magnetic flux commonly for both said winding portions.

7. A D.C. motor and an associated switch circuit as set forth in claim 1 further including a D.C. voltage supply comprising a pair of terminals across which a D.C. voltage is provided, and in which said first terminations are connected to one of said pair of terminals of said D.C. voltage supply, and said commonly connected second terminations are connected to the other of said pair of terminals of said D.C. voltage supply.

8. A D.C. motor land an associated switch circuit as set forth in claim 1 in which said commutator means comprises a single commutator, engaged both by said first pair of brushes and by said second pair of brushes.

9. A D.C. motor and an associated switch circuit as set forth in claim 8 in which said first and second brushes of said first pair of brushes and said first and second brushes of said second pair of brushes are disposed at 90°

intervals about the motor axis, and said first and second brushes of each pair are disposed 90°

apart from each.

10. A D.C. motor and an associated switch circuit as set forth in claim 8 in which said second terminations have a common connection internal of the D.C. motor.

11. A D.C. motor and an associated switch circuit as set forth in claim 8 in which said second terminations have a common connection external of the D.C. motor.

12. A D.C. motor and an associated switch circuit as set forth in claim 8 in which said winding portions are disposed respectively on different respective ferromagnetic portions of said armature core.

13. A D.C. motor and an associated switch circuit as set forth in claim 12 in which said magnetic flux source comprises a first permanent magnet portion providing magnetic flux for said one winding portion, and a second permanent magnet portion providing magnetic flux for said other winding portion.

14. A D.C. motor and an associated switch circuit as set forth in claim 8 further including a D.C. voltage supply comprising a pair of terminals across which a D.C. voltage is provided, and in which said first terminations are connected to one of said pair of terminals of said D.C. voltage supply, and said commonly connected second terminations are connected to the other of said pair of terminals of said D.C. voltage supply.

15. A D.C. motor and an associated switch circuit for selecting between forward and reverse motor rotation about a motor axis comprising:

a D.C. motor comprising a stator and an armature, said armature comprising two armature winding portions disposed on an armature core, said stator comprising a magnetic flux source providing magnetic flux across an air gap between said stator and armature for interaction with said winding portions;

one of said winding portions comprising forward-rotation-causing windings for causing rotation of said armature in a forward sense, the other of said winding portions comprising reverse-rotation-causing windings for causing rotation of said armature in a reverse sense;

commutator means disposed on said armature and connected with said winding portions;

brushes disposed on said stator and engaging said commutator means for delivering electric current to said winding portions via said commutator means;

said associated switch circuit comprising a first circuit branch connected via certain of said brushes and said commutator means to include said one winding portion and a second circuit branch connected via certain of said brushes and said commutator means to include said other winding portion;

said first and second circuit branches comprising terminations via which the respective circuit branch can be connected across a D.C. voltage supply;

said first circuit branch comprising a first selectively operable switch connected between a first brush and one termination for selectively establishing and disestablishing a current flow path through said first circuit branch; and

said second circuit branch comprising a second selectively operable switch connected between a second brush and another termination for selectively establishing and disestablishing a current flow path through said second circuit branch.