US3875495A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamo-electric rotary transformer
Assignee: ELECTRIC MOTION CONTROL CORP INTERNATIONAL
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Filing: 1973-05-07
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Granted: 1975-04-01
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Expires: 1993-05-07
Abstract
Abstract The properties of a rotary DC-to-DC transformer, such as may be used for control of traction motors and the like, comprising a dynamo-electric machine with movable secondary brushes, are significantly improved by providing two sets of counter-rotating secondary brushes which are maintained in symmetrical angular relation to the primary brush set and which share the secondary current. That structure reduces both the maximum energy loss due to armature resistance and the maximum armature reaction mmf to one quarter of their conventional values. Such improved rotary transformers become a practicable means for obtaining smooth motor control and automatic regenerative braking. Circuitry is described for correcting or compensating the armature reaction in such machines, including compensation of the reaction component due to torque current in a rotary transformer having its rotor and a controlled direct current motor differentially coupled to an output shaft. With dual output, the invention provides combined speed and steering control for vehicles.
Inventors
- 👤 Robert D Middlebrook
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:31
CPC Classifications
H; H01; H01R; H01R39/00; H01R39/02; H01R39/44; H02; H02M; H02M3/00; H02M3/22; H02M3/34; H02M3/38; H02M3/40
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
198 words
Dynamo-electric apparatus for transforming direct current electric power between a constant supply voltage and a controllably variable output voltage, said apparatus including a rotor journaled on a rotor axis and having electrically coupled commutator means and armature winding means, substantially magnetically saturated field structure cooperating electromagnetically with the armature winding means, supply terminal means for connection to a source of direct current supply voltage, output terminal means for connection to external means for utilizing the direct current output voltage, and a set of primary brushes engaging the commutator means at electrically neutral angular position and electrically connected to the supply terminal means for producing rotor rotation, said apparatus further comprising two sets of secondary brushes engaging the commutator means and mounted for rotary movement about the axis, control means for adjustably rotating the secondary brush sets through equal angles and in opposite directions with respect to the position of the primary brush set, and circuit means connecting the secondary brush sets to the output terminal means for producing at said terminal means direct current voltages responsive to said control means and for normally supplying to said terminal means substantially equal secondary direct currents from the respective brush sets.
Claim 2
Dependent Claim
198 words
Dynamo-electric apparatus for transforming direct current electric power between a constant supply voltage and a controllably variable output voltage, said apparatus including a rotor journaled on a rotor axis and having electrically coupled commutator means and armature winding means, substantially magnetically saturated field structure cooperating electromagnetically with the armature winding means, supply terminal means for connection to a source of direct current supply voltage, output terminal means for connection to external means for utilizing the direct current output voltage, and a set of primary brushes engaging the commutator means at electrically neutral angular position and electrically connected to the supply terminal means for producing rotor rotation, said apparatus further comprising two sets of secondary brushes engaging the commutator means and mounted for rotary movement about the axis, control means for adjustably rotating the secondary brush sets through equal angles and in opposite directions with respect to the position of the primary brush set, and circuit means connecting the secondary brush sets to the output terminal means for producing at said terminal means direct current voltages responsive to said control means and for normally supplying to said terminal means substantially equal secondary direct currents from the respective brush sets.
Claim 3
Dependent Claim
31 words
Dynamo-electric apparatus according to claim 1 in which said two secondary brush sets are rotatable continuously between positions aligned with said primary brush set and positions spaced 180 electrical degrees therefrom.
Claim 4
Dependent Claim
25 words
Dynamo-electric apparatus according to claim 1 including means for mechanically coupling said rotor to an external device for utilizing mechanical power derived from the rotor.
Claim 5
Dependent Claim
121 words
Dynamo-electric apparatus according to claim 1 in which said field structure comprises main magnetic pole structure and field winding means magnetically coupled thereto, and field circuit means for producing in the field winding means first and second direct current components which are magnetically additive, the value of the first component being constant and selected to substantially saturate the magnetic pole structure, and the value of the second component being variable, said field circuit means including means for maintaining said second component substantially proportional to the sum of the absolute magnitudes of the currents flowing in the secondary brush sets with a factor of proportionality selected to compensate only the parallel components of the total armature reaction mmf due to said currents.
Claim 6
Dependent Claim
38 words
Dynamo-electric apparatus according to claim 4 in which said field circuit means comprise diode rectifying circuit means connected in series with the secondary brush sets and connected to said field winding means for producing said second current component.
Claim 7
Dependent Claim
59 words
Dynamo-electric apparatus according to claim 1 in which said field struCture comprises main magnetic pole structure and main and auxiliary field winding means magnetically coupled thereto, main field circuit means for energizing the main field winding means, and auxiliary field circuit means for connecting each of said secondary brush sets in series relation with the auxiliary field winding means.
Claim 8
Dependent Claim
47 words
Dynamo-electric apparatus according to claim 6 in which said auxiliary field circuit means include rectifying circuit means for so directing current in the auxiliary field winding means that the main and auxiliary winding means are magnetically additive independently of the current direction in the secondary brush sets.
Claim 9
Dependent Claim
41 words
Dynamo-electric apparatus according to claim 6 in which said auxiliary field winding means comprise at least two distinct auxiliary field windings, and said auxiliary field circuit means comprise means for connecting said windings in series with the respective secondary brush sets.
Claim 10
Dependent Claim
48 words
Dynamo-electric apparatus according to claim 8 in which said auxiliary field circuit means include rectifying circuit means for each said auxiliary field winding for so directing current therein that the main and auxiliary winding means are magnetically additive independently of the current direction in the secondary brush sets.
Claim 11
Dependent Claim
65 words
Dynamo-electric apparatus according to claim 1 including also a dynamo-electric machine having a rotor and having an input brush set electrically connected via said output terminal means to said secondary brush sets in parallel to form a secondary circuit, said machine having separately excited field structure, and an output shaft differentially coupled to the respective rotors of said dynamo-electric apparatus and of said dynamo-electric machine.
Claim 12
Dependent Claim
58 words
Dynamo-electric apparatus according to claim 10 in which said field structure of said dynamo-electric apparatus includes compensation winding means, and means for supplying to the compensation winding means a current proportional to the current flowing in said secondary circuit to compensate the armature reaction due to the current component in the primary brush set resulting from rotor torque.
Claim 13
Dependent Claim
78 words
Dynamo-electric apparatus according to claim 10 in which said field structure of said dynamo-electric apparatus includes auxiliary field winding means comprising over-excitation winding means and compensation winding means, means for supplying to the over-excitation winding means a current having a constant direction and corresponding in magnitude to the current flowing in said secondary circuit, and means for supplying to the compensation winding means a current corresponding in magnitude and direction to the current flowing in said secondary circuit.
Claim 14
Dependent Claim
68 words
Dynamo-electric apparatus according to claim 10 and in which said field structure of said dynamo-electric apparatus includes over-excitation winding means, and means for supplying to the over-excitation winding means a current having a constant direction and having a magnitude corresponding to the current flowing in said secondary circuit and of such value as to correct the maximum armature reaction due to all currents flowing in said armature means.
Claim 15
Dependent Claim
96 words
Dynamo-electric apparatus according to claim 1 including also two similar voltage utilization devices electrically connected via said output terminal means to the respective said secondary brush sets, said control means including a manual control handle coupled to said secondary brush sets and movable in one coordinate for adjustably rotating the secondary brush sets through equal angles in opposite directions to produce like variations of the voltages applied to the respective devices, and movable in another coordinate for rotating the secondary brush sets in the same direction to vary differentially the voltages applied to the respective devices.
Claim 16
Dependent Claim
68 words
Dynamo-electric apparatus according to claim 14 in which said other coordinate of handle movement coMprises rotation about a handle axis on which a planet gear is journaled, and said one coordinate of handle movement comprises swinging of the handle and handle axis about a swing axis which is perpendicular to the handle axis and on which are journaled two sun gears coupled to the respective secondary brush sets.
Claim 17
Dependent Claim
38 words
Dynamo-electric apparatus according to claim 14 in which said voltage utilization devices are separately excited direct current motors coupled to respective mechanical loads which are driven at speeds that are normally similar and are subject to differential variation.
Claim 18
Dependent Claim
31 words
Dynamo-electric apparatus according to claim 1 in which said output terminal means comprise two output terminals and said circuit means connect said secondary brush sets in parallel between the output terminals.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |