US3569804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct current motor with stationary armature and field
Assignee: National Aeronautics and Space Administration
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Filing: 1968-08-20
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Granted: 1971-03-09
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Expires: 1988-08-20
Abstract
Abstract This disclosure describes a direct current (DC) motor structure having stationary (immovable) field and armature windings. A rotor formed of a material having high magnetic permeability and having a plurality of salient poles is rotatably mounted adjacent to the field winding so that the field winding electromagnetically induces magnetic flux in the poles. The armature windings are also mounted adjacent to the rotor. In operation, the magnetic flux induced in the poles interacts with the current passing through the armature windings. The current flow in the armature windings is controlled by a solid-state commutator in a manner normally associated with brushless DC motors. By controlling the magnitude of the current supplied to the field windings, the speed of the motor is controlled. In addition, the windings can be connected in a series, shunt or compound configuration as desired.
Inventors
- 👤 Philip A Studer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:23
CPC Classifications
H; H02; H02K; H02K41/00; H02K41/02; H02K41/03; H02K29/00; H02K29/06; H02K29/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
152 words
An electronically commutated brushless direct current would field motor comprising: and armature mounted in a stationary position; a field winding mounted in a stationary position; a rotor having salient poles mounted for rotation on a shaft, said armature, field and shaft aLl mounted in a housing; said rotor mounted so that magnetic flux is induced in said poles by said field and so that said induced magnetic field interacts with current flow through said armature causing rotation of said rotor; control means directly connected to said armature and field for controlling the flow of current through said armature and the flow of current through said field; position-sensing means mounted in said housing and connected to said control means for sensing the position of said rotor and for applying a control signal to said control means and chopping means mechanically connected to said rotor for generating a position signal in said position-sensing means.
Claim 2
Dependent Claim
152 words
An electronically commutated brushless direct current would field motor comprising: and armature mounted in a stationary position; a field winding mounted in a stationary position; a rotor having salient poles mounted for rotation on a shaft, said armature, field and shaft aLl mounted in a housing; said rotor mounted so that magnetic flux is induced in said poles by said field and so that said induced magnetic field interacts with current flow through said armature causing rotation of said rotor; control means directly connected to said armature and field for controlling the flow of current through said armature and the flow of current through said field; position-sensing means mounted in said housing and connected to said control means for sensing the position of said rotor and for applying a control signal to said control means and chopping means mechanically connected to said rotor for generating a position signal in said position-sensing means.
Claim 3
Dependent Claim
28 words
An electronically commutated brushless direct current motor as claimed in claim 1 wherein said shaft is fixedly attached to said housing and said rotor rotates about said shaft.
Claim 4
Dependent Claim
149 words
An electronically commutated brushless direct current motor as claimed in claim 2 wherein said rotor comprises: a front rotor support cone rotatably mounted on said shaft; a back rotor support cone rotatably mounted on said shaft; a front rotor section mounted on said front rotor support cone, said front rotor section being ring-shaped and having a plurality of teeth that project outwardly from one side of said ring in a direction parallel to the axis of said ring, said teeth projecting into a space between said field winding and said armature winding; and a back rotor section mounted on said back rotor support cone, said back rotor section being ring-shaped and having a plurality of teeth that project outwardly from one side of said ring in a direction parallel to the axis of said ring, said teeth projecting into the space between said armature winding and said field winding.
Claim 5
Dependent Claim
34 words
An electronically commutated brushless direct current motor as claimed in claim 3 including a rotor spacing member mounted between the teeth of said front rotor section and the teeth of said back rotor section.
Claim 6
Dependent Claim
112 words
An electronically commutated brushless direct current motor as claimed in claim 4 wherein: said chopping means comprises a ring-shaped light chopping element attached to said front rotor support cone, said light chopping element having a plurality of apertures located on its periphery; and said position sensing means comprises a lamp, said lamp mounted in said housing so as to project light through the apertures in said ring-shaped light chopping element when said apertures are in predetermined positions, and a photocell, said photocell mounted in said housing so as to detect light passing from said lamp through said apertures in said ring-shaped light chopping element when said apertures are in said predetermined positions.
Claim 7
Dependent Claim
28 words
An electronically commutated brushless direct current motor as claimed in claim 1 wherein said shaft rotates in said housing and said rotor is fixedly attached to said shaft.
Claim 8
Dependent Claim
81 words
An electronically commutated brushless direct current motor as claimed in claim 9 wherein said rotor comprises: a front rotor section, said front rotor section being ring-shaped and having a plurality of salient poles that project outwardly and pass aid field and said armature when said rotor is rotated; and a back rotor section, said back rotor section being ring-shaped and having a plurality of salient poles that project outwardly and pass said field and said armature when said rotor is rotated.
Claim 9
Dependent Claim
112 words
An electronically commutated brushless direct current motor as claimed in claim 7 wherein: said chopping means comprises a ring-shaped light chopping disc attached to one of said rotor sections, said light chopping disc having a plurality of apertures located on its periphery; and said position sensing means comprises a lamp, said lamp mounted in said housing so as to project light through the apertures in said ring-shaped light chopping disc when said apertures are in predetermined positions, and a photocell, said photocell mounted in said housing so as to detect light Passing from said lamp through said apertures in said ring-shaped light chopping disc when said apertures are in said predetermined positions.
References Cited (Backward Citations)
US3134039A
Cited
US3304450A
Cited
US3215878A
Cited
US3283191A
Cited
US3299335A
Cited
US3319100A
Cited
US3321652A
Cited
US3374410A
Cited
US3418550A
Cited
US3467844A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |