US3596155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Load-balancing circuit for parallel dc motors
Assignee: Caterpillar Inc
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Filing: 1969-09-24
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Granted: 1971-07-27
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Expires: 1989-09-24
Abstract
Abstract A load-balancing system for paralleled DC motors wherein the field of a separate exciter is connected between the armature circuits of a pair of motors while the armature of the separate exciter is coupled to the fields of the motors to reduce the load unbalance between the motors.
Inventors
- 👤 James T Huxtable
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:27
CPC Classifications
H; H02; H02P; H02P5/00; H02P5/68
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
167 words
A load-balancing system for paralleled DC motors, each of said motors having a field winding divided into two half windings, said system comprising: a separate exciter having an armature and field winding, said exciter field winding being coupled between the armatures of said motors; first circuit means connecting one half winding of one motor field winding in series with one half winding of the other field; second circuit means connecting the remaining half winding of said motor field windings in series; third circuit means connecting said armature of said separate exciter between said first and second circuit means so that current from said exciter flows through said motor fields in opposite directions; and a separate controlled source with leads connecting said first and second circuit means in parallel with said separate controlled source whereby the excitation levels created by said series connected remaining windings are respectively assisted and reduced by current flow in said series connected windings in said first circuit means when any load unbalance occurs.
Claim 2
Dependent Claim
167 words
A load-balancing system for paralleled DC motors, each of said motors having a field winding divided into two half windings, said system comprising: a separate exciter having an armature and field winding, said exciter field winding being coupled between the armatures of said motors; first circuit means connecting one half winding of one motor field winding in series with one half winding of the other field; second circuit means connecting the remaining half winding of said motor field windings in series; third circuit means connecting said armature of said separate exciter between said first and second circuit means so that current from said exciter flows through said motor fields in opposite directions; and a separate controlled source with leads connecting said first and second circuit means in parallel with said separate controlled source whereby the excitation levels created by said series connected remaining windings are respectively assisted and reduced by current flow in said series connected windings in said first circuit means when any load unbalance occurs.
Claim 3
Dependent Claim
38 words
The system of claim 1 wherein said separate exciter is provided with switch means for reversing the flow of current through the armature of the separate exciter when the direction of rotation of said DC motors is reversed.
Claim 4
Dependent Claim
17 words
The load-balancing system of claim 1 wherein said separate exciter is driven at a substantially constant speed.
Claim 5
Dependent Claim
19 words
The load-balancing system of claim 1 wherein said DC motors are the traction motors of an electrically driven vehicle.
Claim 6
Dependent Claim
56 words
The load-balancing system of claim 4 wherein said vehicle includes a prime mover drivingly connected to a DC generator, said generator supplying power to the armatures of said DC motors, said prime mover also being drivingly connected to said separate exciter and governor means on said prime mover to operate it at a substantially constant speed.
Claim 7
Independent Claim
153 words
A method for balancing the load between two DC motors with their armatures connected in parallel to a generator, said method comprising: dividing the field windings of each motor in two halves, connecting a one-half field winding of one of said motors in series to a one-half field winding of said other motor and in parallel to a controlled external excitation source, connecting the remaining one-half field windings of said motors in series and in parallel to said controlled external excitation source, sensing any unbalance in current flow between said armatures of said motors, and utilizing said unbalance to generate a separate current between said series connected one-half field windings whose amplitude is related to sensed unbalance and whose direction in said series connected one-half windings respectively assists and reduces excitation level of said remaIning one-half windings in said motors excited from said controlled external source in a manner to balance the load.
Claim 8
Independent Claim
153 words
A method for balancing the load between two DC motors with their armatures connected in parallel to a generator, said method comprising: dividing the field windings of each motor in two halves, connecting a one-half field winding of one of said motors in series to a one-half field winding of said other motor and in parallel to a controlled external excitation source, connecting the remaining one-half field windings of said motors in series and in parallel to said controlled external excitation source, sensing any unbalance in current flow between said armatures of said motors, and utilizing said unbalance to generate a separate current between said series connected one-half field windings whose amplitude is related to sensed unbalance and whose direction in said series connected one-half windings respectively assists and reduces excitation level of said remaIning one-half windings in said motors excited from said controlled external source in a manner to balance the load.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |